How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

On Tue, 27 Jan 2015 09:12:43 +0630, yyy378
wrote:

How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes.

Sounds like you're doing construction. How about a long heavy duty
extension cord for the scanner until you get to a circuit not affected
by the saw. Or, find a receptacle possibly closer to you for the
scanner that is not on the same phase as the saw. (110 volt saw?)
That is, which uses a breaker that is on the left half of the breaker
box if the saw uses a braker that is on the right half. This assumes
you have receptacles on both sides of the breaker box. Check back if
you only have lights on the other side. I don't know how big your
building is or how many boxes there are.

This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

Or put the saw on a long heavy duty extension cord, but that's my second
choice because the saw must use a lot more power and might be impeded by
a long extension cord. (Although I have my lawn mower on a 100' foot
heavy duty (but I forget what gauge) extension cord, which is plugged
into an 8 foot light duty extension cord, and I have no problem. (well
it mows the grass well.)

On Tue, 27 Jan 2015 09:12:43 +0630, yyy378
wrote:

How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

That's a very significant voltage drop.
I'd start by making sure you have a large enough cable feeding that saw.
If possible, move the saw so it's wired right near the main service
entrance (breaker box).

If that dont fix the problem, (If the saw is 120V), wure it to the
opposite leg of the system on a 240V system.

If course we dont know if you might have 3 phase wiring, or if the saw's
motor is 120 or 240 volts. If that motor is 120v, it might be worth the
cost to change it to a 240V motor, which will run more efficiently.
Also, could that motor possibly be failing, or have a weak capacitor? A
draw that heavy might mean that motor is a little undersize too.

It's real hard to say whats causing this without seeing all the
components and wiring layout.

Before you invest any significant money in this, call your power company
to inspect the pole transformer and all wiring up on the pole. The
transformer might be too small. They should have a number to identify
their rating, for example a home may have a 10KVA or 15KVA transformer.
But there could be multiple houses /buildings on that same transformer.
Yours could just be too small or feeding too many other buildings.
There could also be a loose connection up at the pole, or the cables to
your building, at the meter, or in your breaker box. All of that should
be checked. Maybe the service entrance is too small for your needs.

I'd begin with the call to the power company to check the pole
transformer. They are required to do that all the way to your elec
meter. All wirring AFTER the meter is your responsibility to check or
hire an electrician to do it. But if you show the power company the
problem, they might take a look at your system and maybe suggest
something, if it's not just needing a bigger transformer.

Here is a little thing I ran across some years ago. A local auto
service garage had a very large air compressor. At the rear of the
garage was a restroom. More than once, while waiting to have some work
done on my car, I'd go in that restroom, and notice the incandescent
lightbulb get real dim when the compressor kicked on.

One day I go in there and see he changed the bulb to a CFL. The
compressor started and the CFL shut off entirely for a few seconds. I
said to the owner, "what's with that light in your restroom". He said
it's always that way when the compressor kicks on, and he's had several
of those CFLs burn out after only a few weeks.

The next time I went there, he had an incandescent bulb in there again.
(I think those surges just killed those CFLs).

A couple years ago, they got a new compressor. He said the old one just
died one day and it was time for a new one. The new one is as big if
not a little bigger than the old one. Ever since that new compressor
was installed, I no longer notice the restroom bulb get dim when the
comp. kicks on. I dont know if any wiring was changed when the new
compressor was installed, but that light dimming has now stopped. Maybe
that motor was failing or under rated, or it could be bad wiring or
other things.....

What you explain is probably shortening the life of all your computers
too.

What happens if you were to remnove that uninterrupted power supply, and
run the scanner directly? Maybe that uninterrupted power supply is weak
too. Either way, you have a problem which could damage all your
sensitive electronics. I'd not leave it like that very long.

BTW: Have you connected a volt meter to that scanner outlet and watched
what the voltage dropped to when he saw kicked on? Most places have
between 115 and 120 volts during normal use. But I've seen readings as
low as 110 and high as 124. Still fairly normal. If you see a drop
below 110, you have a problem....

On 1/26/2015 11:35 PM, wrote:
On Tue, 27 Jan 2015 09:12:43 +0630, yyy378
wrote:

How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

If it is that important to you,. buy a ferro resonant power
conditioner for the scanner.

You might also be able to go inside the scanner and put some big
capacitors on the DC power supply.

I don't understand this at all.
The purpose of a UPS is to prevent that from happening.
You need a better ups...or maybe the batteries are just weak
and not really doing their thing.

Maybe you can put the scanner and the saw on different circuits?
Depending on the wiring of the building that may or may not help.

Having your ups restart every two minutes sounds like "asking for trouble!"

yyy378 wrote:
How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the voltage
drops for a split of a second. This has no immediate effect except on the
scanner. Even though the scanner is plugged into an uninterrupted power
supply, if the saw starts and the scanner is in the middle of scanning,
the scanner will stop and scanning is aborted. When the saw starts, the
uninterrupted power supply produces a click sound. It seems the
protection mechanism is kicked in. Why are the computers not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

An on-line UPS is a power conditioner. Tend to be a few bucks. This would
be connected to the scanner.

Greg

On 01/26/2015 09:42 PM, yyy378 wrote:
How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners, lights, etc. However, we also have a 14" saw. When it starts, the voltage drops for a split of a second. This has no immediate effect except on the scanner. Even though the scanner is plugged into an uninterrupted power supply, if the saw starts and the scanner is in the middle of scanning, the scanner will stop and scanning is aborted. When the saw starts, the uninterrupted power supply produces a click sound. It seems the protection mechanism is kicked in. Why are the computers not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner useless. Is there a device I can add to the saw to minimize the voltage drop? Thanks in advance for all the help.

Is the saw on the same breaker as the scanner?

On 27/01/2015 14:26, mike wrote:
On 1/26/2015 11:35 PM, wrote:
On Tue, 27 Jan 2015 09:12:43 +0630, yyy378
wrote:

How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

If it is that important to you,. buy a ferro resonant power
conditioner for the scanner.

You might also be able to go inside the scanner and put some big
capacitors on the DC power supply.

I don't understand this at all.
The purpose of a UPS is to prevent that from happening.
You need a better ups...or maybe the batteries are just weak
and not really doing their thing.

Maybe you can put the scanner and the saw on different circuits?
Depending on the wiring of the building that may or may not help.

Having your ups restart every two minutes sounds like "asking for trouble!"

I don't understand it either. A computer, monitor, and the scanner are
plugged into the same power strip which, in turn, is plugged into a UPS.
I don't know why the computer is not affected. Perhaps it has something
to do with the power supply of the computer.

I'll try piggybacking one UPS to another to see if that helps.

On 27/01/2015 11:27, wrote:
On Tue, 27 Jan 2015 09:12:43 +0630, yyy378
wrote:

How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

That's a very significant voltage drop.
I'd start by making sure you have a large enough cable feeding that saw.
If possible, move the saw so it's wired right near the main service
entrance (breaker box).

If that dont fix the problem, (If the saw is 120V), wure it to the
opposite leg of the system on a 240V system.

If course we dont know if you might have 3 phase wiring, or if the saw's
motor is 120 or 240 volts. If that motor is 120v, it might be worth the
cost to change it to a 240V motor, which will run more efficiently.
Also, could that motor possibly be failing, or have a weak capacitor? A
draw that heavy might mean that motor is a little undersize too.

It's real hard to say whats causing this without seeing all the
components and wiring layout.

Before you invest any significant money in this, call your power company
to inspect the pole transformer and all wiring up on the pole. The
transformer might be too small. They should have a number to identify
their rating, for example a home may have a 10KVA or 15KVA transformer.
But there could be multiple houses /buildings on that same transformer.
Yours could just be too small or feeding too many other buildings.
There could also be a loose connection up at the pole, or the cables to
your building, at the meter, or in your breaker box. All of that should
be checked. Maybe the service entrance is too small for your needs.

I'd begin with the call to the power company to check the pole
transformer. They are required to do that all the way to your elec
meter. All wirring AFTER the meter is your responsibility to check or
hire an electrician to do it. But if you show the power company the
problem, they might take a look at your system and maybe suggest
something, if it's not just needing a bigger transformer.

Here is a little thing I ran across some years ago. A local auto
service garage had a very large air compressor. At the rear of the
garage was a restroom. More than once, while waiting to have some work
done on my car, I'd go in that restroom, and notice the incandescent
lightbulb get real dim when the compressor kicked on.

One day I go in there and see he changed the bulb to a CFL. The
compressor started and the CFL shut off entirely for a few seconds. I
said to the owner, "what's with that light in your restroom". He said
it's always that way when the compressor kicks on, and he's had several
of those CFLs burn out after only a few weeks.

The next time I went there, he had an incandescent bulb in there again.
(I think those surges just killed those CFLs).

A couple years ago, they got a new compressor. He said the old one just
died one day and it was time for a new one. The new one is as big if
not a little bigger than the old one. Ever since that new compressor
was installed, I no longer notice the restroom bulb get dim when the
comp. kicks on. I dont know if any wiring was changed when the new
compressor was installed, but that light dimming has now stopped. Maybe
that motor was failing or under rated, or it could be bad wiring or
other things.....

What you explain is probably shortening the life of all your computers
too.

What happens if you were to remnove that uninterrupted power supply, and
run the scanner directly? Maybe that uninterrupted power supply is weak
too. Either way, you have a problem which could damage all your
sensitive electronics. I'd not leave it like that very long.

BTW: Have you connected a volt meter to that scanner outlet and watched
what the voltage dropped to when he saw kicked on? Most places have
between 115 and 120 volts during normal use. But I've seen readings as
low as 110 and high as 124. Still fairly normal. If you see a drop
below 110, you have a problem....




This is 220 V. The transformer is 100 KVA, 3 phase. It feeds one office,
one warehouse, and one office/shop which is where I reside. The office
has lights, computers, A/C, etc. No heavy machine. The warehouse has
mainly lights. There are only two cables coming to this office/shop.
Thus, it can only be single phase. There are two breaker panels wired in
parallel. I have tried putting the saw to the other breaker panel (two
are 10 meters away) to no avail. I guess this is what is expected for
parallel panels.

Although the power is supposed to be 220 V, the needle on a refrigerator
safeguard points to something like 210V. When the saw starts, the
voltage may drop to something like 170 or 180 V (difficult to tell by a
needle.)

This is a new saw, about one month old. I hope the motor is not failing.

We have a 30 KVA generator dedicated to our building only. Next time
when it runs, I'll watch closely to see if the voltage drop happens
again. If it won't happen, I can be quite sure the incoming power lines
is the culprit. If it happens again, I don't know what to do next. Would
changing the saw cable to a bigger one (smaller gauge number) help? I
have no clue.

On 27/01/2015 16:02, Mike Homes wrote:
On 01/26/2015 09:42 PM, yyy378 wrote:
How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in
the middle of scanning, the scanner will stop and scanning is aborted.
When the saw starts, the uninterrupted power supply produces a click
sound. It seems the protection mechanism is kicked in. Why are the
computers not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the
voltage drop? Thanks in advance for all the help.

Is the saw on the same breaker as the scanner?

Same breaker panel but not same breaker. I have tried plugging the saw
to another breaker panel to no avail. The two breaker panels are
parallel, not serial.

On Tue, 27 Jan 2015 17:06:27 +0630, yyy378
wrote:



That's a very significant voltage drop.
I'd start by making sure you have a large enough cable feeding that saw.
If possible, move the saw so it's wired right near the main service
entrance (breaker box).

If that dont fix the problem, (If the saw is 120V), wure it to the
opposite leg of the system on a 240V system.

If course we dont know if you might have 3 phase wiring, or if the saw's
motor is 120 or 240 volts. If that motor is 120v, it might be worth the
cost to change it to a 240V motor, which will run more efficiently.
Also, could that motor possibly be failing, or have a weak capacitor? A
draw that heavy might mean that motor is a little undersize too.

It's real hard to say whats causing this without seeing all the
components and wiring layout.

Before you invest any significant money in this, call your power company
to inspect the pole transformer and all wiring up on the pole. The
transformer might be too small. They should have a number to identify
their rating, for example a home may have a 10KVA or 15KVA transformer.
But there could be multiple houses /buildings on that same transformer.
Yours could just be too small or feeding too many other buildings.
There could also be a loose connection up at the pole, or the cables to
your building, at the meter, or in your breaker box. All of that should
be checked. Maybe the service entrance is too small for your needs.

I'd begin with the call to the power company to check the pole
transformer. They are required to do that all the way to your elec
meter. All wirring AFTER the meter is your responsibility to check or
hire an electrician to do it. But if you show the power company the
problem, they might take a look at your system and maybe suggest
something, if it's not just needing a bigger transformer.

Here is a little thing I ran across some years ago. A local auto
service garage had a very large air compressor. At the rear of the
garage was a restroom. More than once, while waiting to have some work
done on my car, I'd go in that restroom, and notice the incandescent
lightbulb get real dim when the compressor kicked on.

One day I go in there and see he changed the bulb to a CFL. The
compressor started and the CFL shut off entirely for a few seconds. I
said to the owner, "what's with that light in your restroom". He said
it's always that way when the compressor kicks on, and he's had several
of those CFLs burn out after only a few weeks.

The next time I went there, he had an incandescent bulb in there again.
(I think those surges just killed those CFLs).

A couple years ago, they got a new compressor. He said the old one just
died one day and it was time for a new one. The new one is as big if
not a little bigger than the old one. Ever since that new compressor
was installed, I no longer notice the restroom bulb get dim when the
comp. kicks on. I dont know if any wiring was changed when the new
compressor was installed, but that light dimming has now stopped. Maybe
that motor was failing or under rated, or it could be bad wiring or
other things.....

What you explain is probably shortening the life of all your computers
too.

What happens if you were to remnove that uninterrupted power supply, and
run the scanner directly? Maybe that uninterrupted power supply is weak
too. Either way, you have a problem which could damage all your
sensitive electronics. I'd not leave it like that very long.

BTW: Have you connected a volt meter to that scanner outlet and watched
what the voltage dropped to when he saw kicked on? Most places have
between 115 and 120 volts during normal use. But I've seen readings as
low as 110 and high as 124. Still fairly normal. If you see a drop
below 110, you have a problem....




This is 220 V. The transformer is 100 KVA, 3 phase. It feeds one office,
one warehouse, and one office/shop which is where I reside. The office
has lights, computers, A/C, etc. No heavy machine. The warehouse has
mainly lights. There are only two cables coming to this office/shop.
Thus, it can only be single phase. There are two breaker panels wired in
parallel. I have tried putting the saw to the other breaker panel (two
are 10 meters away) to no avail. I guess this is what is expected for
parallel panels.

Seems like that should be adaquate for the transformer and wiring.

Although the power is supposed to be 220 V, the needle on a refrigerator
safeguard points to something like 210V. When the saw starts, the
voltage may drop to something like 170 or 180 V (difficult to tell by a
needle.)

I'm not sure how that refrigerator setup is wired, but if it's reading
the voltage directly off the source wires, you have a BIG PROBLEM.
You're dropping nearly 50V below the required voltage.

Now take a plain multimeter, set it to AC Volts, 250V or higher scale.
Then SAFELY measure the voltage at the mains. If you're not comfortable
doing this, find someone who is or call an electrician.

An electrician will have equipment to measure current draw too, which
would be helpful.

This is a new saw, about one month old. I hope the motor is not failing.

Anything is possible, but ot's less likely with a new saw.

We have a 30 KVA generator dedicated to our building only. Next time
when it runs, I'll watch closely to see if the voltage drop happens
again. If it won't happen, I can be quite sure the incoming power lines
is the culprit. If it happens again, I don't know what to do next. Would
changing the saw cable to a bigger one (smaller gauge number) help? I
have no clue.

Shuting off the GRID power and running the generator would be a good way
to check to see if the same problems occur. If not, then you know there
is a problem with the power source from the GRID.

I think you have a bigger problem than the saw cable. Too small of a
cable would starve the saw motor, leading to eventual motor damage. It
should not drop voltage in th building by 50v.

BVut just to know, what is the amperage of that saw? What gauge is the
cable (cord). How long is the cord? Are you using an extension cord?
(what gauge is the ext cord if you have one). What size breaker is
feeding that saw?

Besides what I already said, the NEXT thing you should do is call your
power company. After all, part of the reason you pay them, is to
maintain PROPER power for your needs. They should not charge you to do
an equipment check. Maybe you have everything on one leg of the 3 phase
and the other two are sitting idle???? (Unbalanced load).

One other thought. You have that 30KVA generator. There has to be a
switching device that completely isolates the generator from the GRID.
(REQUIRED by code to prevent backfeeding into the GRID.)

There could be some sort of problem with that switching device.....

On 1/27/2015 5:06 AM, yyy378 wrote:


On 27/01/2015 14:26, mike wrote:
On 1/26/2015 11:35 PM, wrote:
On Tue, 27 Jan 2015 09:12:43 +0630, yyy378
wrote:

How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

If it is that important to you,. buy a ferro resonant power
conditioner for the scanner.

You might also be able to go inside the scanner and put some big
capacitors on the DC power supply.

I don't understand this at all.
The purpose of a UPS is to prevent that from happening.
You need a better ups...or maybe the batteries are just weak
and not really doing their thing.

Maybe you can put the scanner and the saw on different circuits?
Depending on the wiring of the building that may or may not help.

Having your ups restart every two minutes sounds like "asking for
trouble!"

I don't understand it either. A computer, monitor, and the scanner are
plugged into the same power strip which, in turn, is plugged into a UPS.
I don't know why the computer is not affected. Perhaps it has something
to do with the power supply of the computer.

I'll try piggybacking one UPS to another to see if that helps.

Well, the 1st thing I'd try is to plug the scanner directly into the
power and not through the UPS. Most UPSs actually switch the output
from the mains to the inverter built inside. Some UPSs actually run the
load on the inverter all the time. This would probably be good in you
case, however, those UPSs are getting fewer and farther between.
Computer power supplies tend to have enough storage to hold during the
switchover, however, most scanners use a small wall wart power supply
and may not have enough capacitance to hold over during the switchover.
If that doesn't work, I'd try replacing the wall wart. Some are
switching power supplies (more are going this way now) and some are
analog. That probably doesn't make a difference as it's all in how much
capacitance (holdover capability) it has. So, if the plug to the
scanner is a generic plug, changing the wall wart should be easy.

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

On 1/27/2015 5:39 AM, yyy378 wrote:



Is the saw on the same breaker as the scanner?

Same breaker panel but not same breaker. I have tried plugging the saw
to another breaker panel to no avail. The two breaker panels are
parallel, not serial.

You'd get better results if you put it on the opposite phase.

On Tuesday, January 27, 2015 at 2:56:19 AM UTC-5, mike wrote:
On 1/26/2015 11:35 PM, wrote:
On Tue, 27 Jan 2015 09:12:43 +0630, yyy378
wrote:

How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

If it is that important to you,. buy a ferro resonant power
conditioner for the scanner.

You might also be able to go inside the scanner and put some big
capacitors on the DC power supply.

I don't understand this at all.
The purpose of a UPS is to prevent that from happening.
You need a better ups...or maybe the batteries are just weak
and not really doing their thing.

Maybe you can put the scanner and the saw on different circuits?
Depending on the wiring of the building that may or may not help.

Having your ups restart every two minutes sounds like "asking for trouble!"

+1

It sounds like the UPS is no good. If it can't handle a voltage drop,
what's it going to do with a power loss, etc? First thing I'd do is just
try plugging the scanner in directly, no UPS and see what happens. It's
possible the UPS senses the power drop, then screws up in the response.
The scanner might tolerate the momentary drop in voltage. IDK why you need
a UPS on a scanner anyway.

Aside from that, some investigation into the sizing of the conductors,
what circuits loads are on, what the root cause is, would be worthwhile too.

On 1/27/2015 5:36 AM, yyy378 wrote:



This is 220 V. The transformer is 100 KVA, 3 phase. It feeds one office,
one warehouse, and one office/shop which is where I reside. The office
has lights, computers, A/C, etc. No heavy machine. The warehouse has
mainly lights. There are only two cables coming to this office/shop.
Thus, it can only be single phase. There are two breaker panels wired in
parallel. I have tried putting the saw to the other breaker panel (two
are 10 meters away) to no avail. I guess this is what is expected for
parallel panels.

Although the power is supposed to be 220 V, the needle on a refrigerator
safeguard points to something like 210V. When the saw starts, the
voltage may drop to something like 170 or 180 V (difficult to tell by a
needle.)

This is a new saw, about one month old. I hope the motor is not failing.

We have a 30 KVA generator dedicated to our building only. Next time
when it runs, I'll watch closely to see if the voltage drop happens
again. If it won't happen, I can be quite sure the incoming power lines
is the culprit. If it happens again, I don't know what to do next. Would
changing the saw cable to a bigger one (smaller gauge number) help? I
have no clue.

It may or may not be the incoming lines. I'd say though, that wiring at
some point is not up to the job as you are trying to suck a lot of juice
through a small straw. It could be the lines to the panels. I've seen
similar situations when a power tool is on too small of a line even
though there was plenty of power coming to the panel from the stret.
Moving things around to distribute the load properly and assuring the
individual lines are adequate is the way to start. If you are not
familiar with tracing loads, get an electrician and he can do it for you.

On Tue, 27 Jan 2015 16:36:58 +0630, yyy378
wrote in

I don't understand it either. A computer, monitor, and the scanner are
plugged into the same power strip which, in turn, is plugged into a UPS.
I don't know why the computer is not affected. Perhaps it has something
to do with the power supply of the computer.

I'll try piggybacking one UPS to another to see if that helps.

Is it possible that the UPS feeding the scanner is defective?
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Web based forums are like subscribing to 10 different newspapers
and having to visit 10 different news stands to pickup each one.
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newspapers delivered to your door every morning.

How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

That's a very significant voltage drop.
I'd start by making sure you have a large enough cable feeding that saw.
If possible, move the saw so it's wired right near the main service
entrance (breaker box).

If that dont fix the problem, (If the saw is 120V), wure it to the
opposite leg of the system on a 240V system.

If course we dont know if you might have 3 phase wiring, or if the saw's
motor is 120 or 240 volts. If that motor is 120v, it might be worth the
cost to change it to a 240V motor, which will run more efficiently.
Also, could that motor possibly be failing, or have a weak capacitor? A
draw that heavy might mean that motor is a little undersize too.

It's real hard to say whats causing this without seeing all the
components and wiring layout.

Before you invest any significant money in this, call your power company
to inspect the pole transformer and all wiring up on the pole. The
transformer might be too small. They should have a number to identify
their rating, for example a home may have a 10KVA or 15KVA transformer.
But there could be multiple houses /buildings on that same transformer.
Yours could just be too small or feeding too many other buildings.
There could also be a loose connection up at the pole, or the cables to
your building, at the meter, or in your breaker box. All of that should
be checked. Maybe the service entrance is too small for your needs.

I'd begin with the call to the power company to check the pole
transformer. They are required to do that all the way to your elec
meter. All wirring AFTER the meter is your responsibility to check or
hire an electrician to do it. But if you show the power company the
problem, they might take a look at your system and maybe suggest
something, if it's not just needing a bigger transformer.

Here is a little thing I ran across some years ago. A local auto
service garage had a very large air compressor. At the rear of the
garage was a restroom. More than once, while waiting to have some work
done on my car, I'd go in that restroom, and notice the incandescent
lightbulb get real dim when the compressor kicked on.

One day I go in there and see he changed the bulb to a CFL. The
compressor started and the CFL shut off entirely for a few seconds. I
said to the owner, "what's with that light in your restroom". He said
it's always that way when the compressor kicks on, and he's had several
of those CFLs burn out after only a few weeks.

The next time I went there, he had an incandescent bulb in there again.
(I think those surges just killed those CFLs).

A couple years ago, they got a new compressor. He said the old one just
died one day and it was time for a new one. The new one is as big if
not a little bigger than the old one. Ever since that new compressor
was installed, I no longer notice the restroom bulb get dim when the
comp. kicks on. I dont know if any wiring was changed when the new
compressor was installed, but that light dimming has now stopped. Maybe
that motor was failing or under rated, or it could be bad wiring or
other things.....

What you explain is probably shortening the life of all your computers
too.

What happens if you were to remnove that uninterrupted power supply, and
run the scanner directly? Maybe that uninterrupted power supply is weak
too. Either way, you have a problem which could damage all your
sensitive electronics. I'd not leave it like that very long.

BTW: Have you connected a volt meter to that scanner outlet and watched
what the voltage dropped to when he saw kicked on? Most places have
between 115 and 120 volts during normal use. But I've seen readings as
low as 110 and high as 124. Still fairly normal. If you see a drop
below 110, you have a problem....




This is 220 V. The transformer is 100 KVA, 3 phase. It feeds one office,
one warehouse, and one office/shop which is where I reside. The office
has lights, computers, A/C, etc. No heavy machine. The warehouse has
mainly lights. There are only two cables coming to this office/shop.
Thus, it can only be single phase. There are two breaker panels wired in
parallel. I have tried putting the saw to the other breaker panel (two
are 10 meters away) to no avail. I guess this is what is expected for
parallel panels.

Although the power is supposed to be 220 V, the needle on a refrigerator
safeguard points to something like 210V. When the saw starts, the
voltage may drop to something like 170 or 180 V (difficult to tell by a
needle.)

This is a new saw, about one month old. I hope the motor is not failing.

We have a 30 KVA generator dedicated to our building only. Next time
when it runs, I'll watch closely to see if the voltage drop happens
again. If it won't happen, I can be quite sure the incoming power lines
is the culprit. If it happens again, I don't know what to do next. Would
changing the saw cable to a bigger one (smaller gauge number) help? I
have no clue.


*You may be able to change the taps on the transformer to boost the voltage. There should be a wiring diagram on the inside or outside of the transformer. Power would have to be shut off to the entire transformer to make the change.

Boy! This **** is way outa my reach, fellers.
I'll just stick to my rubber saws and screwdrivers.

On 27/01/2015 20:50, John G wrote:
How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

That's a very significant voltage drop.
I'd start by making sure you have a large enough cable feeding that saw.
If possible, move the saw so it's wired right near the main service
entrance (breaker box).

If that dont fix the problem, (If the saw is 120V), wure it to the
opposite leg of the system on a 240V system.

If course we dont know if you might have 3 phase wiring, or if the saw's
motor is 120 or 240 volts. If that motor is 120v, it might be worth the
cost to change it to a 240V motor, which will run more efficiently.
Also, could that motor possibly be failing, or have a weak capacitor? A
draw that heavy might mean that motor is a little undersize too.

It's real hard to say whats causing this without seeing all the
components and wiring layout.

Before you invest any significant money in this, call your power company
to inspect the pole transformer and all wiring up on the pole. The
transformer might be too small. They should have a number to identify
their rating, for example a home may have a 10KVA or 15KVA transformer.
But there could be multiple houses /buildings on that same transformer.
Yours could just be too small or feeding too many other buildings.
There could also be a loose connection up at the pole, or the cables to
your building, at the meter, or in your breaker box. All of that should
be checked. Maybe the service entrance is too small for your needs.

I'd begin with the call to the power company to check the pole
transformer. They are required to do that all the way to your elec
meter. All wirring AFTER the meter is your responsibility to check or
hire an electrician to do it. But if you show the power company the
problem, they might take a look at your system and maybe suggest
something, if it's not just needing a bigger transformer.

Here is a little thing I ran across some years ago. A local auto
service garage had a very large air compressor. At the rear of the
garage was a restroom. More than once, while waiting to have some work
done on my car, I'd go in that restroom, and notice the incandescent
lightbulb get real dim when the compressor kicked on.

One day I go in there and see he changed the bulb to a CFL. The
compressor started and the CFL shut off entirely for a few seconds. I
said to the owner, "what's with that light in your restroom". He said
it's always that way when the compressor kicks on, and he's had several
of those CFLs burn out after only a few weeks.

The next time I went there, he had an incandescent bulb in there again.
(I think those surges just killed those CFLs).

A couple years ago, they got a new compressor. He said the old one just
died one day and it was time for a new one. The new one is as big if
not a little bigger than the old one. Ever since that new compressor
was installed, I no longer notice the restroom bulb get dim when the
comp. kicks on. I dont know if any wiring was changed when the new
compressor was installed, but that light dimming has now stopped. Maybe
that motor was failing or under rated, or it could be bad wiring or
other things.....

What you explain is probably shortening the life of all your computers
too.

What happens if you were to remnove that uninterrupted power supply, and
run the scanner directly? Maybe that uninterrupted power supply is weak
too. Either way, you have a problem which could damage all your
sensitive electronics. I'd not leave it like that very long.

BTW: Have you connected a volt meter to that scanner outlet and watched
what the voltage dropped to when he saw kicked on? Most places have
between 115 and 120 volts during normal use. But I've seen readings as
low as 110 and high as 124. Still fairly normal. If you see a drop
below 110, you have a problem....




This is 220 V. The transformer is 100 KVA, 3 phase. It feeds one office,
one warehouse, and one office/shop which is where I reside. The office
has lights, computers, A/C, etc. No heavy machine. The warehouse has
mainly lights. There are only two cables coming to this office/shop.
Thus, it can only be single phase. There are two breaker panels wired in
parallel. I have tried putting the saw to the other breaker panel (two
are 10 meters away) to no avail. I guess this is what is expected for
parallel panels.

Although the power is supposed to be 220 V, the needle on a refrigerator
safeguard points to something like 210V. When the saw starts, the
voltage may drop to something like 170 or 180 V (difficult to tell by a
needle.)

This is a new saw, about one month old. I hope the motor is not failing.

We have a 30 KVA generator dedicated to our building only. Next time
when it runs, I'll watch closely to see if the voltage drop happens
again. If it won't happen, I can be quite sure the incoming power lines
is the culprit. If it happens again, I don't know what to do next. Would
changing the saw cable to a bigger one (smaller gauge number) help? I
have no clue.


*You may be able to change the taps on the transformer to boost the voltage. There should be a wiring diagram on the inside or outside of the transformer. Power would have to be shut off to the entire transformer to make the change.


We rent this place. Power cables go from the transformer to landlord's
office building. Everything has to go through the landlord. Anyway, last
week an electrician came, checked the system, and claimed the system has
no problems. There is nothing he can do. Well, I don't know how much I
can trust the electrician. The government (Burma) doesn't have electric
code and doesn't issue licenses for electricians. Virtually anyone can
be an electrician.

On 27/01/2015 20:44, CRNG wrote:
On Tue, 27 Jan 2015 16:36:58 +0630, yyy378
wrote in

I don't understand it either. A computer, monitor, and the scanner are
plugged into the same power strip which, in turn, is plugged into a UPS.
I don't know why the computer is not affected. Perhaps it has something
to do with the power supply of the computer.

I'll try piggybacking one UPS to another to see if that helps.

Is it possible that the UPS feeding the scanner is defective?

I'll try a different one and see.

On 01/26/2015 08:42 PM, yyy378 wrote:
How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.



The UPS is evidently only "consumer grade".

You'd be better off with a Ferroresonant transformer type UPS.

It will not cut out at all and in a worst case scenario just drop by a
couple of volts...but more importantly...zero interruption.


They are of course more expensive.


It may be better to just find a completely separate circuit for the saw

"yyy378" wrote in message
...


On 27/01/2015 14:26, mike wrote:
On 1/26/2015 11:35 PM, wrote:
On Tue, 27 Jan 2015 09:12:43 +0630, yyy378
wrote:

How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

If it is that important to you,. buy a ferro resonant power
conditioner for the scanner.

You might also be able to go inside the scanner and put some big
capacitors on the DC power supply.

I don't understand this at all.
The purpose of a UPS is to prevent that from happening.
You need a better ups...or maybe the batteries are just weak
and not really doing their thing.

Maybe you can put the scanner and the saw on different circuits?
Depending on the wiring of the building that may or may not help.

Having your ups restart every two minutes sounds like "asking for
trouble!"

I don't understand it either. A computer, monitor, and the scanner are
plugged into the same power strip which, in turn, is plugged into a UPS. I
don't know why the computer is not affected. Perhaps it has something to
do with the power supply of the computer.

I'll try piggybacking one UPS to another to see if that helps.

Another thought, assuming the UPS unit or units are working properly, is to
cut the power to the UPS while the scanner operates, let the UPS carry the
load for a few seconds, and switch the power back on when the scanner is
done. That way the saw, whatever it's doing, can't affect anything on the
plug strip.

TK



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On 1/27/2015 12:34 PM, wrote:
On Tue, 27 Jan 2015 08:36:30 -0500, Art Todesco
wrote:

On 1/27/2015 5:06 AM, yyy378 wrote:


On 27/01/2015 14:26, mike wrote:
On 1/26/2015 11:35 PM, wrote:
On Tue, 27 Jan 2015 09:12:43 +0630, yyy378
wrote:

How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

If it is that important to you,. buy a ferro resonant power
conditioner for the scanner.

You might also be able to go inside the scanner and put some big
capacitors on the DC power supply.

I don't understand this at all.
The purpose of a UPS is to prevent that from happening.
You need a better ups...or maybe the batteries are just weak
and not really doing their thing.

Maybe you can put the scanner and the saw on different circuits?
Depending on the wiring of the building that may or may not help.

Having your ups restart every two minutes sounds like "asking for
trouble!"

I don't understand it either. A computer, monitor, and the scanner are
plugged into the same power strip which, in turn, is plugged into a UPS.
I don't know why the computer is not affected. Perhaps it has something
to do with the power supply of the computer.

I'll try piggybacking one UPS to another to see if that helps.

Well, the 1st thing I'd try is to plug the scanner directly into the
power and not through the UPS. Most UPSs actually switch the output
from the mains to the inverter built inside. Some UPSs actually run the
load on the inverter all the time. This would probably be good in you
case, however, those UPSs are getting fewer and farther between.
Computer power supplies tend to have enough storage to hold during the
switchover, however, most scanners use a small wall wart power supply
and may not have enough capacitance to hold over during the switchover.
If that doesn't work, I'd try replacing the wall wart. Some are
switching power supplies (more are going this way now) and some are
analog. That probably doesn't make a difference as it's all in how much
capacitance (holdover capability) it has. So, if the plug to the
scanner is a generic plug, changing the wall wart should be easy.


If this is a wall wart supply, the capacitor trick is easy. Get a male
cord and female connector the right size and just plug the capacitor
in across the line.

If it's a DC output wall wart. Some are AC.

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On 27/01/2015 18:46, wrote:
On Tue, 27 Jan 2015 17:06:27 +0630, yyy378
wrote:



That's a very significant voltage drop.
I'd start by making sure you have a large enough cable feeding that saw.
If possible, move the saw so it's wired right near the main service
entrance (breaker box).

If that dont fix the problem, (If the saw is 120V), wure it to the
opposite leg of the system on a 240V system.

If course we dont know if you might have 3 phase wiring, or if the saw's
motor is 120 or 240 volts. If that motor is 120v, it might be worth the
cost to change it to a 240V motor, which will run more efficiently.
Also, could that motor possibly be failing, or have a weak capacitor? A
draw that heavy might mean that motor is a little undersize too.

It's real hard to say whats causing this without seeing all the
components and wiring layout.

Before you invest any significant money in this, call your power company
to inspect the pole transformer and all wiring up on the pole. The
transformer might be too small. They should have a number to identify
their rating, for example a home may have a 10KVA or 15KVA transformer.
But there could be multiple houses /buildings on that same transformer.
Yours could just be too small or feeding too many other buildings.
There could also be a loose connection up at the pole, or the cables to
your building, at the meter, or in your breaker box. All of that should
be checked. Maybe the service entrance is too small for your needs.

I'd begin with the call to the power company to check the pole
transformer. They are required to do that all the way to your elec
meter. All wirring AFTER the meter is your responsibility to check or
hire an electrician to do it. But if you show the power company the
problem, they might take a look at your system and maybe suggest
something, if it's not just needing a bigger transformer.

Here is a little thing I ran across some years ago. A local auto
service garage had a very large air compressor. At the rear of the
garage was a restroom. More than once, while waiting to have some work
done on my car, I'd go in that restroom, and notice the incandescent
lightbulb get real dim when the compressor kicked on.

One day I go in there and see he changed the bulb to a CFL. The
compressor started and the CFL shut off entirely for a few seconds. I
said to the owner, "what's with that light in your restroom". He said
it's always that way when the compressor kicks on, and he's had several
of those CFLs burn out after only a few weeks.

The next time I went there, he had an incandescent bulb in there again.
(I think those surges just killed those CFLs).

A couple years ago, they got a new compressor. He said the old one just
died one day and it was time for a new one. The new one is as big if
not a little bigger than the old one. Ever since that new compressor
was installed, I no longer notice the restroom bulb get dim when the
comp. kicks on. I dont know if any wiring was changed when the new
compressor was installed, but that light dimming has now stopped. Maybe
that motor was failing or under rated, or it could be bad wiring or
other things.....

What you explain is probably shortening the life of all your computers
too.

What happens if you were to remnove that uninterrupted power supply, and
run the scanner directly? Maybe that uninterrupted power supply is weak
too. Either way, you have a problem which could damage all your
sensitive electronics. I'd not leave it like that very long.

BTW: Have you connected a volt meter to that scanner outlet and watched
what the voltage dropped to when he saw kicked on? Most places have
between 115 and 120 volts during normal use. But I've seen readings as
low as 110 and high as 124. Still fairly normal. If you see a drop
below 110, you have a problem....




This is 220 V. The transformer is 100 KVA, 3 phase. It feeds one office,
one warehouse, and one office/shop which is where I reside. The office
has lights, computers, A/C, etc. No heavy machine. The warehouse has
mainly lights. There are only two cables coming to this office/shop.
Thus, it can only be single phase. There are two breaker panels wired in
parallel. I have tried putting the saw to the other breaker panel (two
are 10 meters away) to no avail. I guess this is what is expected for
parallel panels.

Seems like that should be adaquate for the transformer and wiring.

Although the power is supposed to be 220 V, the needle on a refrigerator
safeguard points to something like 210V. When the saw starts, the
voltage may drop to something like 170 or 180 V (difficult to tell by a
needle.)

I'm not sure how that refrigerator setup is wired, but if it's reading
the voltage directly off the source wires, you have a BIG PROBLEM.
You're dropping nearly 50V below the required voltage.

Now take a plain multimeter, set it to AC Volts, 250V or higher scale.
Then SAFELY measure the voltage at the mains. If you're not comfortable
doing this, find someone who is or call an electrician.

An electrician will have equipment to measure current draw too, which
would be helpful.

This is a new saw, about one month old. I hope the motor is not failing.

Anything is possible, but ot's less likely with a new saw.

We have a 30 KVA generator dedicated to our building only. Next time
when it runs, I'll watch closely to see if the voltage drop happens
again. If it won't happen, I can be quite sure the incoming power lines
is the culprit. If it happens again, I don't know what to do next. Would
changing the saw cable to a bigger one (smaller gauge number) help? I
have no clue.

Shuting off the GRID power and running the generator would be a good way
to check to see if the same problems occur. If not, then you know there
is a problem with the power source from the GRID.

I think you have a bigger problem than the saw cable. Too small of a
cable would starve the saw motor, leading to eventual motor damage. It
should not drop voltage in th building by 50v.

BVut just to know, what is the amperage of that saw? What gauge is the
cable (cord). How long is the cord? Are you using an extension cord?
(what gauge is the ext cord if you have one). What size breaker is
feeding that saw?

Besides what I already said, the NEXT thing you should do is call your
power company. After all, part of the reason you pay them, is to
maintain PROPER power for your needs. They should not charge you to do
an equipment check. Maybe you have everything on one leg of the 3 phase
and the other two are sitting idle???? (Unbalanced load).

One other thought. You have that 30KVA generator. There has to be a
switching device that completely isolates the generator from the GRID.
(REQUIRED by code to prevent backfeeding into the GRID.)

There could be some sort of problem with that switching device.....



The electric system in this country is notorious. Every house that can
afford a generator has one. When there is a power outage, you hear
generators humming everywhere. Some people have stabilizer also because
the power from the grid may be only 180 or 190 V.

I have a 30 KVA 3 phase stabilizer. Not sure if it will help or can be
used in a single phase environment.

My multimeter is also analogue. I still have to rely on the needle to
tell the voltage. What I said about 50V drop is just my guess. It is
difficult to tell the actual number from a small needle pointer.

The saw is 2000W, 8.8A. The wire feeding the saw is slightly less than
13 gauge (2.5 mm2 cross section).

The switching device for the generator is a simple double knife switch.
It needs to be manually switched between grid and generator.

On Monday, January 26, 2015 at 9:42:53 PM UTC-5, yyy378 wrote:
How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

Back in the 1970s I worked as coiper service tech. Our buildings wiring was ancient and undersized. copies either came out too light or way too dark depending on the line volatege at the time of the copiers use

my work around was to set the exposure lamp as brite as possible, then the key operator could use a high wattage dimmer to darken the copies as needed......

it worked well for a couple years till the building was demolished for a highway project

"bob haller" wrote in message
...
On Monday, January 26, 2015 at 9:42:53 PM UTC-5, yyy378 wrote:
How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.

Back in the 1970s I worked as coiper service tech. Our buildings wiring
was ancient and undersized. copies either came out too light or way too
dark depending on the line volatege at the time of the copiers use

my work around was to set the exposure lamp as brite as possible, then the
key operator could use a high wattage dimmer to darken the copies as
needed......

it worked well for a couple years till the building was demolished for a
highway project

then what happened?

On Monday, January 26, 2015 at 7:42:53 PM UTC-7, yyy378 wrote:
How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted.

Is it the voltage drop, or is it the line noise accompanied by the
voltage drop? Because if it's just line noise you may be able to
fix the problem by plugging the scanner into a surge protector
containing a line filter made of both inductors and capacitors. Many
surge protectors lack one, as do even some backup power supplies.
For example, I had a cheap 350VA Belkin backup with no such filter
in it, and the computer would freeze or reboot when a laser printer
plugged into the same AC outlet was turned on, but the computer
always ran fine when I instead plugged it into an old APC backup.
Or maybe you just need to try a different AC adapter for the scanner
(be sure it puts out the same voltage and at least as much current
and that its plug is of the correct polarity) because some of those
adapters contain better line filters than others do. If none of that
helps, try plugging the saw into a different AC outlet through a
super-heavy extension cord made of #10 or #12 wire.

On 28/01/2015 09:23, wrote:
On Monday, January 26, 2015 at 7:42:53 PM UTC-7, yyy378 wrote:
How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted.

Is it the voltage drop, or is it the line noise accompanied by the
voltage drop? Because if it's just line noise you may be able to
fix the problem by plugging the scanner into a surge protector
containing a line filter made of both inductors and capacitors. Many
surge protectors lack one, as do even some backup power supplies.
For example, I had a cheap 350VA Belkin backup with no such filter
in it, and the computer would freeze or reboot when a laser printer
plugged into the same AC outlet was turned on, but the computer
always ran fine when I instead plugged it into an old APC backup.
Or maybe you just need to try a different AC adapter for the scanner
(be sure it puts out the same voltage and at least as much current
and that its plug is of the correct polarity) because some of those
adapters contain better line filters than others do. If none of that
helps, try plugging the saw into a different AC outlet through a
super-heavy extension cord made of #10 or #12 wire.

I just measured the voltage with a multimeter. The voltage is 210 V.
Once the saw starts, the voltage drops to around 185V before coming back
to 205 till the saw stops. Then, the voltage goes up to 210.

philo wrote:
On 01/26/2015 08:42 PM, yyy378 wrote:
How to minimize voltage drop caused by heavy machine?

We have a typical office environment including computers, scanners,
lights, etc. However, we also have a 14" saw. When it starts, the
voltage drops for a split of a second. This has no immediate effect
except on the scanner. Even though the scanner is plugged into an
uninterrupted power supply, if the saw starts and the scanner is in the
middle of scanning, the scanner will stop and scanning is aborted. When
the saw starts, the uninterrupted power supply produces a click sound.
It seems the protection mechanism is kicked in. Why are the computers
not affected but only the scanner?

The saw starts roughly every two minutes. This renders the scanner
useless. Is there a device I can add to the saw to minimize the voltage
drop? Thanks in advance for all the help.



The UPS is evidently only "consumer grade".

You'd be better off with a Ferroresonant transformer type UPS.

It will not cut out at all and in a worst case scenario just drop by a
couple of volts...but more importantly...zero interruption.


They are of course more expensive.


It may be better to just find a completely separate circuit for the saw

Best.

I say again, use an on-line ups. It outputs near sine wave. Input power
never sees the output. Sounds like a similar price to a ferro xfmr.

And NO, not two ups in series.

How much does scanner cost ?

Greg

On 27/01/2015 18:46, wrote:
On Tue, 27 Jan 2015 17:06:27 +0630, yyy378
wrote:



That's a very significant voltage drop.
I'd start by making sure you have a large enough cable feeding that saw.
If possible, move the saw so it's wired right near the main service
entrance (breaker box).

If that dont fix the problem, (If the saw is 120V), wure it to the
opposite leg of the system on a 240V system.

If course we dont know if you might have 3 phase wiring, or if the saw's
motor is 120 or 240 volts. If that motor is 120v, it might be worth the
cost to change it to a 240V motor, which will run more efficiently.
Also, could that motor possibly be failing, or have a weak capacitor? A
draw that heavy might mean that motor is a little undersize too.

It's real hard to say whats causing this without seeing all the
components and wiring layout.

Before you invest any significant money in this, call your power company
to inspect the pole transformer and all wiring up on the pole. The
transformer might be too small. They should have a number to identify
their rating, for example a home may have a 10KVA or 15KVA transformer.
But there could be multiple houses /buildings on that same transformer.
Yours could just be too small or feeding too many other buildings.
There could also be a loose connection up at the pole, or the cables to
your building, at the meter, or in your breaker box. All of that should
be checked. Maybe the service entrance is too small for your needs.

I'd begin with the call to the power company to check the pole
transformer. They are required to do that all the way to your elec
meter. All wirring AFTER the meter is your responsibility to check or
hire an electrician to do it. But if you show the power company the
problem, they might take a look at your system and maybe suggest
something, if it's not just needing a bigger transformer.

Here is a little thing I ran across some years ago. A local auto
service garage had a very large air compressor. At the rear of the
garage was a restroom. More than once, while waiting to have some work
done on my car, I'd go in that restroom, and notice the incandescent
lightbulb get real dim when the compressor kicked on.

One day I go in there and see he changed the bulb to a CFL. The
compressor started and the CFL shut off entirely for a few seconds. I
said to the owner, "what's with that light in your restroom". He said
it's always that way when the compressor kicks on, and he's had several
of those CFLs burn out after only a few weeks.

The next time I went there, he had an incandescent bulb in there again.
(I think those surges just killed those CFLs).

A couple years ago, they got a new compressor. He said the old one just
died one day and it was time for a new one. The new one is as big if
not a little bigger than the old one. Ever since that new compressor
was installed, I no longer notice the restroom bulb get dim when the
comp. kicks on. I dont know if any wiring was changed when the new
compressor was installed, but that light dimming has now stopped. Maybe
that motor was failing or under rated, or it could be bad wiring or
other things.....

What you explain is probably shortening the life of all your computers
too.

What happens if you were to remnove that uninterrupted power supply, and
run the scanner directly? Maybe that uninterrupted power supply is weak
too. Either way, you have a problem which could damage all your
sensitive electronics. I'd not leave it like that very long.

BTW: Have you connected a volt meter to that scanner outlet and watched
what the voltage dropped to when he saw kicked on? Most places have
between 115 and 120 volts during normal use. But I've seen readings as
low as 110 and high as 124. Still fairly normal. If you see a drop
below 110, you have a problem....




This is 220 V. The transformer is 100 KVA, 3 phase. It feeds one office,
one warehouse, and one office/shop which is where I reside. The office
has lights, computers, A/C, etc. No heavy machine. The warehouse has
mainly lights. There are only two cables coming to this office/shop.
Thus, it can only be single phase. There are two breaker panels wired in
parallel. I have tried putting the saw to the other breaker panel (two
are 10 meters away) to no avail. I guess this is what is expected for
parallel panels.

Seems like that should be adaquate for the transformer and wiring.

Although the power is supposed to be 220 V, the needle on a refrigerator
safeguard points to something like 210V. When the saw starts, the
voltage may drop to something like 170 or 180 V (difficult to tell by a
needle.)

I'm not sure how that refrigerator setup is wired, but if it's reading
the voltage directly off the source wires, you have a BIG PROBLEM.
You're dropping nearly 50V below the required voltage.

Now take a plain multimeter, set it to AC Volts, 250V or higher scale.
Then SAFELY measure the voltage at the mains. If you're not comfortable
doing this, find someone who is or call an electrician.

An electrician will have equipment to measure current draw too, which
would be helpful.

This is a new saw, about one month old. I hope the motor is not failing.

Anything is possible, but ot's less likely with a new saw.

We have a 30 KVA generator dedicated to our building only. Next time
when it runs, I'll watch closely to see if the voltage drop happens
again. If it won't happen, I can be quite sure the incoming power lines
is the culprit. If it happens again, I don't know what to do next. Would
changing the saw cable to a bigger one (smaller gauge number) help? I
have no clue.

Shuting off the GRID power and running the generator would be a good way
to check to see if the same problems occur. If not, then you know there
is a problem with the power source from the GRID.

I think you have a bigger problem than the saw cable. Too small of a
cable would starve the saw motor, leading to eventual motor damage. It
should not drop voltage in th building by 50v.

BVut just to know, what is the amperage of that saw? What gauge is the
cable (cord). How long is the cord? Are you using an extension cord?
(what gauge is the ext cord if you have one). What size breaker is
feeding that saw?

Besides what I already said, the NEXT thing you should do is call your
power company. After all, part of the reason you pay them, is to
maintain PROPER power for your needs. They should not charge you to do
an equipment check. Maybe you have everything on one leg of the 3 phase
and the other two are sitting idle???? (Unbalanced load).

One other thought. You have that 30KVA generator. There has to be a
switching device that completely isolates the generator from the GRID.
(REQUIRED by code to prevent backfeeding into the GRID.)

There could be some sort of problem with that switching device.....



I just measured the voltage with a multimeter. The voltage is 210 V.
Once the saw starts, it drops for a split of a second to around 185 V
before coming back to 205 V till the saw stops. Then, the voltage goes
up to 210V.

I also measure the voltage at the service entrance. It is 214~215 v.
There is also a 5V drop when the saw is running.

On Wed, 28 Jan 2015 14:30:09 +0630, yyy378
wrote:

helps, try plugging the saw into a different AC outlet through a
super-heavy extension cord made of #10 or #12 wire.

I just measured the voltage with a multimeter. The voltage is 210 V.
Once the saw starts, the voltage drops to around 185V before coming back
to 205 till the saw stops. Then, the voltage goes up to 210.


I saw you post this in a rely to my last message. I did not know you're
outside the USA, which means I am not sure what you really have for
power, or if the power company will help you. However, that is still a
huge voltage drop and not normal. You said the saw is 2000W. That's
not all that large and should not becausing such a drop. Some wiring,
maybe the entrance cables are too small...... I dont know what else to
say!

But here's a thought. Get a 12V Deep Cycle battery and an inverter to
convert to 120V AC. Plug the scanner into the inverter connected to the
battery. Then get a battery charger, probably 5 to 10 amp. Charger,
but make sure it's a charger with "overcharge prevention" (shuts off
when the battery is charged). Connect the charger from an outlet to the
battery. PROBLEM SOLVED. You're running the scanner off the battery!
(Of course make sure the inverter is big enough for the scanner, which I
doubt uses very much power).

yyy378:

My biggest takeaway from all the suggestions here is to get either
the saw or the scanner off the same circuit as the other. If there are
spare circuits in your breaker, have the saw moved to its own.

Simplistic I know, but that's how I think.

On Wednesday, January 28, 2015 at 3:07:12 AM UTC-5, yyy378 wrote:
On 27/01/2015 18:46, wrote:
On Tue, 27 Jan 2015 17:06:27 +0630, yyy378
wrote:



That's a very significant voltage drop.
I'd start by making sure you have a large enough cable feeding that saw.
If possible, move the saw so it's wired right near the main service
entrance (breaker box).

If that dont fix the problem, (If the saw is 120V), wure it to the
opposite leg of the system on a 240V system.

If course we dont know if you might have 3 phase wiring, or if the saw's
motor is 120 or 240 volts. If that motor is 120v, it might be worth the
cost to change it to a 240V motor, which will run more efficiently.
Also, could that motor possibly be failing, or have a weak capacitor? A
draw that heavy might mean that motor is a little undersize too.

It's real hard to say whats causing this without seeing all the
components and wiring layout.

Before you invest any significant money in this, call your power company
to inspect the pole transformer and all wiring up on the pole. The
transformer might be too small. They should have a number to identify
their rating, for example a home may have a 10KVA or 15KVA transformer.
But there could be multiple houses /buildings on that same transformer.
Yours could just be too small or feeding too many other buildings.
There could also be a loose connection up at the pole, or the cables to
your building, at the meter, or in your breaker box. All of that should
be checked. Maybe the service entrance is too small for your needs.

I'd begin with the call to the power company to check the pole
transformer. They are required to do that all the way to your elec
meter. All wirring AFTER the meter is your responsibility to check or
hire an electrician to do it. But if you show the power company the
problem, they might take a look at your system and maybe suggest
something, if it's not just needing a bigger transformer.

Here is a little thing I ran across some years ago. A local auto
service garage had a very large air compressor. At the rear of the
garage was a restroom. More than once, while waiting to have some work
done on my car, I'd go in that restroom, and notice the incandescent
lightbulb get real dim when the compressor kicked on.

One day I go in there and see he changed the bulb to a CFL. The
compressor started and the CFL shut off entirely for a few seconds. I
said to the owner, "what's with that light in your restroom". He said
it's always that way when the compressor kicks on, and he's had several
of those CFLs burn out after only a few weeks.

The next time I went there, he had an incandescent bulb in there again.
(I think those surges just killed those CFLs).

A couple years ago, they got a new compressor. He said the old one just
died one day and it was time for a new one. The new one is as big if
not a little bigger than the old one. Ever since that new compressor
was installed, I no longer notice the restroom bulb get dim when the
comp. kicks on. I dont know if any wiring was changed when the new
compressor was installed, but that light dimming has now stopped. Maybe
that motor was failing or under rated, or it could be bad wiring or
other things.....

What you explain is probably shortening the life of all your computers
too.

What happens if you were to remnove that uninterrupted power supply, and
run the scanner directly? Maybe that uninterrupted power supply is weak
too. Either way, you have a problem which could damage all your
sensitive electronics. I'd not leave it like that very long.

BTW: Have you connected a volt meter to that scanner outlet and watched
what the voltage dropped to when he saw kicked on? Most places have
between 115 and 120 volts during normal use. But I've seen readings as
low as 110 and high as 124. Still fairly normal. If you see a drop
below 110, you have a problem....




This is 220 V. The transformer is 100 KVA, 3 phase. It feeds one office,
one warehouse, and one office/shop which is where I reside. The office
has lights, computers, A/C, etc. No heavy machine. The warehouse has
mainly lights. There are only two cables coming to this office/shop.
Thus, it can only be single phase. There are two breaker panels wired in
parallel. I have tried putting the saw to the other breaker panel (two
are 10 meters away) to no avail. I guess this is what is expected for
parallel panels.

Seems like that should be adaquate for the transformer and wiring.

Although the power is supposed to be 220 V, the needle on a refrigerator
safeguard points to something like 210V. When the saw starts, the
voltage may drop to something like 170 or 180 V (difficult to tell by a
needle.)

I'm not sure how that refrigerator setup is wired, but if it's reading
the voltage directly off the source wires, you have a BIG PROBLEM.
You're dropping nearly 50V below the required voltage.

Now take a plain multimeter, set it to AC Volts, 250V or higher scale.
Then SAFELY measure the voltage at the mains. If you're not comfortable
doing this, find someone who is or call an electrician.

An electrician will have equipment to measure current draw too, which
would be helpful.

This is a new saw, about one month old. I hope the motor is not failing.

Anything is possible, but ot's less likely with a new saw.

We have a 30 KVA generator dedicated to our building only. Next time
when it runs, I'll watch closely to see if the voltage drop happens
again. If it won't happen, I can be quite sure the incoming power lines
is the culprit. If it happens again, I don't know what to do next. Would
changing the saw cable to a bigger one (smaller gauge number) help? I
have no clue.

Shuting off the GRID power and running the generator would be a good way
to check to see if the same problems occur. If not, then you know there
is a problem with the power source from the GRID.

I think you have a bigger problem than the saw cable. Too small of a
cable would starve the saw motor, leading to eventual motor damage. It
should not drop voltage in th building by 50v.

BVut just to know, what is the amperage of that saw? What gauge is the
cable (cord). How long is the cord? Are you using an extension cord?
(what gauge is the ext cord if you have one). What size breaker is
feeding that saw?

Besides what I already said, the NEXT thing you should do is call your
power company. After all, part of the reason you pay them, is to
maintain PROPER power for your needs. They should not charge you to do
an equipment check. Maybe you have everything on one leg of the 3 phase
and the other two are sitting idle???? (Unbalanced load).

One other thought. You have that 30KVA generator. There has to be a
switching device that completely isolates the generator from the GRID.
(REQUIRED by code to prevent backfeeding into the GRID.)

There could be some sort of problem with that switching device.....



I just measured the voltage with a multimeter. The voltage is 210 V.
Once the saw starts, it drops for a split of a second to around 185 V
before coming back to 205 V till the saw stops. Then, the voltage goes
up to 210V.

I also measure the voltage at the service entrance. It is 214~215 v.
There is also a 5V drop when the saw is running.


5 volt drop at the service due to an 8 amp load doesn't sound good.....
IDK what the service rating is, but extrapolating that, if the service
was rated at 100A and you pulled that, you'd have ~60V drop.

On Wednesday, January 28, 2015 at 8:36:15 AM UTC-5, wrote:
yyy378:

My biggest takeaway from all the suggestions here is to get either
the saw or the scanner off the same circuit as the other. If there are
spare circuits in your breaker, have the saw moved to its own.

Simplistic I know, but that's how I think.

Did you see the recent post where he reported that the saw, when running,
pulls 8A and that results in a steady 5V drop measured at the *service*?

On 28/01/2015 20:06, wrote:
yyy378:

My biggest takeaway from all the suggestions here is to get either
the saw or the scanner off the same circuit as the other. If there are
spare circuits in your breaker, have the saw moved to its own.

Simplistic I know, but that's how I think.

I have tried it.

The entrance cable feeds two breaker panels which are wired in parallel.
I have moved the saw from one panel to the other with no noticeable
difference.

On 01/28/2015 02:05 AM, gregz wrote:



The UPS is evidently only "consumer grade".

You'd be better off with a Ferroresonant transformer type UPS.

It will not cut out at all and in a worst case scenario just drop by a
couple of volts...but more importantly...zero interruption.


They are of course more expensive.


It may be better to just find a completely separate circuit for the saw

Best.

I say again, use an on-line ups. It outputs near sine wave. Input power
never sees the output. Sounds like a similar price to a ferro xfmr.

And NO, not two ups in series.



Just though of something I did once and it worked.

I put a ferroresonant line conditioner transformer between a cheap UPS
and the load and it worked fine.

On 28/01/2015 15:14, wrote:
On Wed, 28 Jan 2015 14:30:09 +0630, yyy378
wrote:

helps, try plugging the saw into a different AC outlet through a
super-heavy extension cord made of #10 or #12 wire.

I just measured the voltage with a multimeter. The voltage is 210 V.
Once the saw starts, the voltage drops to around 185V before coming back
to 205 till the saw stops. Then, the voltage goes up to 210.


I saw you post this in a rely to my last message. I did not know you're
outside the USA, which means I am not sure what you really have for
power, or if the power company will help you. However, that is still a
huge voltage drop and not normal. You said the saw is 2000W. That's
not all that large and should not becausing such a drop. Some wiring,
maybe the entrance cables are too small...... I dont know what else to
say!

But here's a thought. Get a 12V Deep Cycle battery and an inverter to
convert to 120V AC. Plug the scanner into the inverter connected to the
battery. Then get a battery charger, probably 5 to 10 amp. Charger,
but make sure it's a charger with "overcharge prevention" (shuts off
when the battery is charged). Connect the charger from an outlet to the
battery. PROBLEM SOLVED. You're running the scanner off the battery!
(Of course make sure the inverter is big enough for the scanner, which I
doubt uses very much power).


2000 w is not much. I just remember that the electric meter is rated
10,000 W. Maybe in this case, 2000 W is not that small.

On Wednesday, January 28, 2015 at 9:14:35 AM UTC-5, yyy378 wrote:
On 28/01/2015 15:14, wrote:
On Wed, 28 Jan 2015 14:30:09 +0630, yyy378
wrote:

helps, try plugging the saw into a different AC outlet through a
super-heavy extension cord made of #10 or #12 wire.

I just measured the voltage with a multimeter. The voltage is 210 V.
Once the saw starts, the voltage drops to around 185V before coming back
to 205 till the saw stops. Then, the voltage goes up to 210.


I saw you post this in a rely to my last message. I did not know you're
outside the USA, which means I am not sure what you really have for
power, or if the power company will help you. However, that is still a
huge voltage drop and not normal. You said the saw is 2000W. That's
not all that large and should not becausing such a drop. Some wiring,
maybe the entrance cables are too small...... I dont know what else to
say!

But here's a thought. Get a 12V Deep Cycle battery and an inverter to
convert to 120V AC. Plug the scanner into the inverter connected to the
battery. Then get a battery charger, probably 5 to 10 amp. Charger,
but make sure it's a charger with "overcharge prevention" (shuts off
when the battery is charged). Connect the charger from an outlet to the
battery. PROBLEM SOLVED. You're running the scanner off the battery!
(Of course make sure the inverter is big enough for the scanner, which I
doubt uses very much power).


2000 w is not much. I just remember that the electric meter is rated
10,000 W. Maybe in this case, 2000 W is not that small.

Doh! That's about a 40A service? Even so, if the conductors are
properly sized and everything is in proper order, a 2000W load
shouldn't drop the service voltage 5V.

trader_4 wrote:

Did you see the recent post where he reported that the saw, when running,
pulls 8A and that results in a steady 5V drop measured at the *service*?

What's the service, a hamster wheel? Or a breaker box fed by 100 feet of
cheap extension cord?

On Wednesday, January 28, 2015 at 9:52:47 AM UTC-5, rbowman wrote:
trader_4 wrote:

Did you see the recent post where he reported that the saw, when running,
pulls 8A and that results in a steady 5V drop measured at the *service*?

What's the service, a hamster wheel? Or a breaker box fed by 100 feet of
cheap extension cord?

Did you see the next recent post, where he reported that the meter is
rated 10KW? Not exactly a hamster wheel, but it sounds like 40A.
Given that he says the 8A motor load drops it by 5V, the 100ft of
cheap extension cord, or cheap something, sounds possible.

On Wednesday, January 28, 2015 at 9:13:19 AM UTC-5, yyy378 wrote:
On 28/01/2015 20:06, wrote:
yyy378:

My biggest takeaway from all the suggestions here is to get either
the saw or the scanner off the same circuit as the other. If there are
spare circuits in your breaker, have the saw moved to its own.

Simplistic I know, but that's how I think.

I have tried it.

The entrance cable feeds two breaker panels which are wired in parallel.
I have moved the saw from one panel to the other with no noticeable
difference.

Since you were seeing a 5V drop at the service itself, that makes sense.