On 5/9/2011 1:26 PM, Bob La Londe wrote:
On 5/8/2011 10:15 PM, Gunner Asch wrote:
Ive got a 5hp PC3 vfd running my Gorton MasterMill.
The top end voltage it is supposed to run on..is 230vts + about 5 volts
It will run down to 200 volts.
Im running it on single phase, been doing it for years.

Now the power company has increased my 220 single phase to about 249
volts and when I try to start it..I keep getting OverVoltage Alarm.

I cant get the power company to change the tap down to a normal voltage,
let alone 220 volts

How do I (cheaply) transform high voltage down 14-29 volts ac?

Id hate to loose the VFD on this mill and have to run it off a RPC
(which also puts out higher voltages)

Gunner


This question comes from the "expert" in machine repair and electrical
things? most people who use electricity would know about autotransformers

On 2011-05-09, azotic wrote:

"Gunner Asch" wrote in message
...
Ive got a 5hp PC3 vfd running my Gorton MasterMill.
The top end voltage it is supposed to run on..is 230vts + about 5 volts
It will run down to 200 volts.
Im running it on single phase, been doing it for years.

Now the power company has increased my 220 single phase to about 249
volts and when I try to start it..I keep getting OverVoltage Alarm.

I cant get the power company to change the tap down to a normal voltage,
let alone 220 volts

How do I (cheaply) transform high voltage down 14-29 volts ac?

Id hate to loose the VFD on this mill and have to run it off a RPC
(which also puts out higher voltages)

Gunner

Variac of approiate size, or a triac type voltage regulator control.
Big ass light dimmer ?

A TRIAC light dimmer is *not* going to produce a reasonable
waveform for the input to a VVD -- sorry.

A big enough Variac or Powerstat could do it -- often without
even needing to use the adjustable wiper if the taps are right.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On May 9, 9:16*pm, "Pete C." wrote:
Gunner Asch wrote:

On Mon, 9 May 2011 14:43:24 -0700 (PDT), Cross-Slide
wrote:

Or is the output 24 volts?

I see I havent gotten everything back from the stroke....sigh

If you do a search on "buck boost wiring" you will find references for
how to wire one of your transformers to "buck" your 249V down to 225V.
Basically, the 24V secondary goes in series with the feed to your RPC,
and the primary just connects to the line. The secondary amp rating at
24V has to be enough to handle the load of your RPC/machine.

http://www.jhlarson.com/ind_tables/G...uckboost01.htm

If your transformers are large enough to handle the single phase load
see single phase diagram A and you'll need only one transformer.

http://www.jhlarson.com/ind_tables/G...uckboost03.htm

If the transformers are only large enough for the three phase load
you'll need to use three of them after the RPC. See diagram F, which is
really the same as the single phase setup in triplicate.

NOOOO !!

Never put a transformer in the Output of a VFD!
It is variable frequency... Those transformers are NOT going to be
amused with 20 HZ !!

Keep the Buck transformers in the Line side, where they get 60 hz.
just the way they like it..

Correct. Even I remembered this G

Except we're talking about an RPC, not a VFD.

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

" Ive got a 5hp PC3 vfd running my Gorton MasterMill.
The top end voltage it is supposed to run on..is 230vts + about 5
volts
It will run down to 200 volts.
Im running it on single phase, been doing it for years. "

azotic wrote:

"Gunner Asch" wrote in message
...
Ive got a 5hp PC3 vfd running my Gorton MasterMill.
The top end voltage it is supposed to run on..is 230vts + about 5 volts
It will run down to 200 volts.
Im running it on single phase, been doing it for years.

Now the power company has increased my 220 single phase to about 249
volts and when I try to start it..I keep getting OverVoltage Alarm.

I cant get the power company to change the tap down to a normal voltage,
let alone 220 volts

How do I (cheaply) transform high voltage down 14-29 volts ac?

Id hate to loose the VFD on this mill and have to run it off a RPC
(which also puts out higher voltages)

Gunner

Variac of approiate size, or a triac type voltage regulator control.
Big ass light dimmer ?


NO!!! Light dimmers are phase controllers and play hell with other
equipment.


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "


It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

Gunner -

There are two methods -

make the input 246 volts drop across two transformer windings - and
one goes to nothing. But the best is on the secondary.

Have your main transformer attached.
In parallel to it - e.g. same breakers and same on/off.....

The secondary is '24v' AC. The wires are phase generating.
One when put in series with the main power secondary - adds - and you
get 280v or something. Swap the 24v wires (or the primary if easier)
and you get 220v across both.


The secondary current has to be equal or more than that of the
big transformer secondary.

5700 volt-amp = wattage (no phase angle)
5700W/220V = 26 amp ? maybe 30.0 amp. So the 24v transformer has to
have a 30 amp or more secondary current.

I can do a drawing for you if you need. I do this method on my 3-phase.

Martin



On 5/9/2011 2:55 AM, Gunner Asch wrote:
On Mon, 09 May 2011 00:06:29 -0700, Gunner
wrote:

On Mon, 09 May 2011 01:19:57 -0400, "Michael A. Terrell"
wrote:


Gunner Asch wrote:

Ive got a 5hp PC3 vfd running my Gorton MasterMill.
The top end voltage it is supposed to run on..is 230vts + about 5 volts
It will run down to 200 volts.
Im running it on single phase, been doing it for years.

Now the power company has increased my 220 single phase to about 249
volts and when I try to start it..I keep getting OverVoltage Alarm.

I cant get the power company to change the tap down to a normal voltage,
let alone 220 volts

How do I (cheaply) transform high voltage down 14-29 volts ac?

Id hate to loose the VFD on this mill and have to run it off a RPC
(which also puts out higher voltages)


How much current do you need? A simple buck transformer will do the
job, as long as it's secondary can handle the current.

I believe its 5.7kva

Gunner

Ok...Im going to look REALLY stupid here. Sigh..blame it on the stroke.
Or not..shrug

Ive got a BUNCH of 120/240 transformers..all marked 120/240 12/24

So if I wire one up to 240..does it mean that it will REDUCE the voltage
-24 volts?

Or is the output 24 volts?

I see I havent gotten everything back from the stroke....sigh

Gunner

DoN. Nichols wrote:

A big enough Variac or Powerstat could do it -- often without
even needing to use the adjustable wiper if the taps are right.

Or a 24V buck/boost in buck mode, for about 10% of the cost.

Cheers!
Rich

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

On Mon, 09 May 2011 19:48:23 -0700, "." wrote:

On 5/9/2011 1:26 PM, Bob La Londe wrote:
On 5/8/2011 10:15 PM, Gunner Asch wrote:
Ive got a 5hp PC3 vfd running my Gorton MasterMill.
The top end voltage it is supposed to run on..is 230vts + about 5 volts
It will run down to 200 volts.
Im running it on single phase, been doing it for years.

Now the power company has increased my 220 single phase to about 249
volts and when I try to start it..I keep getting OverVoltage Alarm.

I cant get the power company to change the tap down to a normal voltage,
let alone 220 volts

How do I (cheaply) transform high voltage down 14-29 volts ac?

Id hate to loose the VFD on this mill and have to run it off a RPC
(which also puts out higher voltages)

Gunner


This question comes from the "expert" in machine repair and electrical
things? most people who use electricity would know about autotransformers

Expert? Who might that be? It obviously isnt me, and it damned sure
isnt you. Hell..you dont even have a name. So Ill just pick one so I can
address you. Humm...Cockbite? No..thats already taken...let me
see....VulvaFace? No..he is over on another
newsgroup....hummm...Asshat?..Nope..that guy is on a Liberal site.
****4Brains..thats it....!!

So ****4Brains....how many autotransformers are there in machine tools?
Omniturns? (0) Bridgeports? (0) Gortons? (0)...
In fact..can you name (1)?
Some..some Moogs have (2). Im just starting to learn how to service
Moog/Visimetrics

Heads up ****4Brains...Im a machine tool repair guy. Not a ****ing
electrical engineer. AND I had a stroke about 24 months ago. It took
me over a year before I could even START remembering names of long
standing clients. I could drive there..but couldnt remember their
names. I could ask about their new dogs, their families, how their
vacations went and so forth..but their individual names...nada

Now..Im pretty close to an expert on firearms. Been asked to testify in
court as an expert witness a time or two, even have my name as co-author
of some publications. But ****4Brains...no VFDs or autotransformers on
firearms.

So why dont you pack up your **** and mosey along and see if you can
find another group of adults to pester?

Gunner

--
"If I say two plus two is four and a Democrat says two plus two is eight,
it's not a partial victory for me when we agree that two plus two is
six. " Jonah Goldberg (modified)

On Mon, 09 May 2011 23:56:30 -0500, Martin Eastburn
wrote:

Gunner -

There are two methods -

make the input 246 volts drop across two transformer windings - and
one goes to nothing. But the best is on the secondary.

Have your main transformer attached.
In parallel to it - e.g. same breakers and same on/off.....

The secondary is '24v' AC. The wires are phase generating.
One when put in series with the main power secondary - adds - and you
get 280v or something. Swap the 24v wires (or the primary if easier)
and you get 220v across both.


The secondary current has to be equal or more than that of the
big transformer secondary.

5700 volt-amp = wattage (no phase angle)
5700W/220V = 26 amp ? maybe 30.0 amp. So the 24v transformer has to
have a 30 amp or more secondary current.

I can do a drawing for you if you need. I do this method on my 3-phase.

Martin

Ive got it Martin, but many thanks. It rained yesterday, and I had to
load that old Gorton mill in the rain when Id planned on digging out the
10 or more transformers that Ive got scattered around on the shelves out
back. Now that I know how to do it..Ill do it this coming weekend after
I get back from LA..where Im headed in an hour or so. Just have to load
the truck and be on the road.

I know Ive got some that will be big enough to handle 30 or so amps.

Many thanks!!

Gunner




On 5/9/2011 2:55 AM, Gunner Asch wrote:
On Mon, 09 May 2011 00:06:29 -0700, Gunner
wrote:

On Mon, 09 May 2011 01:19:57 -0400, "Michael A. Terrell"
wrote:


Gunner Asch wrote:

Ive got a 5hp PC3 vfd running my Gorton MasterMill.
The top end voltage it is supposed to run on..is 230vts + about 5 volts
It will run down to 200 volts.
Im running it on single phase, been doing it for years.

Now the power company has increased my 220 single phase to about 249
volts and when I try to start it..I keep getting OverVoltage Alarm.

I cant get the power company to change the tap down to a normal voltage,
let alone 220 volts

How do I (cheaply) transform high voltage down 14-29 volts ac?

Id hate to loose the VFD on this mill and have to run it off a RPC
(which also puts out higher voltages)


How much current do you need? A simple buck transformer will do the
job, as long as it's secondary can handle the current.

I believe its 5.7kva

Gunner

Ok...Im going to look REALLY stupid here. Sigh..blame it on the stroke.
Or not..shrug

Ive got a BUNCH of 120/240 transformers..all marked 120/240 12/24

So if I wire one up to 240..does it mean that it will REDUCE the voltage
-24 volts?

Or is the output 24 volts?

I see I havent gotten everything back from the stroke....sigh

Gunner


--
"If I say two plus two is four and a Democrat says two plus two is eight,
it's not a partial victory for me when we agree that two plus two is
six. " Jonah Goldberg (modified)

Rich Grise wrote:

I wonder what the voltage drop would be across a couple electric range
elements?

It's irrelevant, because that is a Very Bad Idea.

Why? Gunner is likely looking for an inexpensive solution.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.


Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

Wes wrote:

Rich Grise wrote:

I wonder what the voltage drop would be across a couple electric range
elements?

It's irrelevant, because that is a Very Bad Idea.

Why? Gunner is likely looking for an inexpensive solution.


And it's already hot enough in the desert.


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

"Michael A. Terrell" wrote in message
m...

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is "
VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.


Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?


Because in the case of an RPC, the entire downstream bus in all probability
has excessive voltage imbalances when measured phase to phase and even even
a few percent of voltage imbalance has a very profoundly negative effect on
motor temtrature rise and energy losses to core heating....

Are YOU that stupid?

--

"Wes" wrote in message
...
Rich Grise wrote:

I wonder what the voltage drop would be across a couple electric range
elements?

It's irrelevant, because that is a Very Bad Idea.

Why? Gunner is likely looking for an inexpensive solution.


The voltage at load will sag quite a bit--depending on the second series
components' electrical characteristics unless IT also happens to be a purely
resistive load.

--

Michael A. Terrell wrote:
... Are you that stupid?

That's not necessary. Let's keep it civil - it's an RCM tradition.
Pretend that you're talking face-to-face.

Bob

Good luck with that one on Usenet!

But God bless you for it!

------------------

"Bob Engelhardt" wrote in message ...
That's not necessary. Let's keep it civil - it's an RCM tradition.
Pretend that you're talking face-to-face.

Bob

--
Michael A. Terrell wrote:
... Are you that stupid?

PrecisionmachinisT wrote:
....
Are YOU that stupid?

You too - that's enough. Bob

Josepi wrote:
Good luck with that one on Usenet!
....

Yeah, I know about Usenet, but RCM has always been different. An oasis
in a desert of rudeness. It makes such a difference. On many groups
it's so unpleasant reading even when the rudeness is not directed at you.

Bob

"Bob Engelhardt" wrote in message
...
PrecisionmachinisT wrote:
...
Are YOU that stupid?

You too - that's enough. Bob

http://www.youtube.com/watch?v=4qHUb...1&feature=fvwp

--

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

On 2011-05-11, Pete C. wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

Pete C is completely right!!!

i

PrecisionmachinisT wrote:

"Michael A. Terrell" wrote in message
m...

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is "
VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.


Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?


Because in the case of an RPC, the entire downstream bus in all probability
has excessive voltage imbalances when measured phase to phase and even even
a few percent of voltage imbalance has a very profoundly negative effect on
motor temtrature rise and energy losses to core heating....

Are YOU that stupid?


Sigh. Are you saying that you will adjust each transformer as you
change the load?


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.


OK, if a hack job pleases you.


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

On May 12, 12:34*am, "Michael A. Terrell"
wrote:
"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

* *It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

* *Why would you put three after the RPC when one at the input ddoes it
right? *Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

* *OK, if a hack job pleases you.

--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

Remember ......... This multiple transformer idea was in response to a
VFD Question.
A VFD Question ... GET IT?

The original question was about a VFD.
The response was to add transformers to the output.

Do not expect to make it into a sensible discussion. It will not
happen.

"Michael A. Terrell" wrote:

PrecisionmachinisT wrote:

"Michael A. Terrell" wrote in message
m...

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is "
VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.


Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?


Because in the case of an RPC, the entire downstream bus in all probability
has excessive voltage imbalances when measured phase to phase and even even
a few percent of voltage imbalance has a very profoundly negative effect on
motor temtrature rise and energy losses to core heating....

Are YOU that stupid?

Sigh. Are you saying that you will adjust each transformer as you
change the load?

No, I'm saying you use what you have and if you have three small
transformers that will do the job after the RPC, you use those instead
of buying a new transformer.

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

OK, if a hack job pleases you.

A "hack job" utilizing parts you already have on hand vs. spending money
buying new parts will please most HSM folks. We are talking HSM here,
not in a factory where you would have real three phase power anyway.

On May 12, 11:14*am, "Pete C." wrote:
"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

* *It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

* *Why would you put three after the RPC when one at the input ddoes it
right? *Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

* *OK, if a hack job pleases you.

A "hack job" utilizing parts you already have on hand vs. spending money
buying new parts will please most HSM folks. We are talking HSM here,
not in a factory where you would have real three phase power anyway

Wait! You're both right! But, I just re-read the original post. Gunner
doesn't make it clear whether the overvoltage alarm is coming from the
mill or from the VFD. If the latter, then you'd have to make the
adjustment on the single-phase input. If the former, you could do the
adjustment on either end, depending on what transformers you have on
hand.

On May 12, 10:41*am, rangerssuck wrote:
On May 12, 11:14*am, "Pete C." wrote:



"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

* *It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

* *Why would you put three after the RPC when one at the input ddoes it
right? *Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

* *OK, if a hack job pleases you.

A "hack job" utilizing parts you already have on hand vs. spending money
buying new parts will please most HSM folks. We are talking HSM here,
not in a factory where you would have real three phase power anyway

Wait! You're both right! But, I just re-read the original post. Gunner
doesn't make it clear whether the overvoltage alarm is coming from the
mill or from the VFD. If the latter, then you'd have to make the
adjustment on the single-phase input. If the former, you could do the
adjustment on either end, depending on what transformers you have on
hand.

For the eleventh time... You cannot use transformers on the output of
a VFD !

"Michael A. Terrell" wrote in message
...

PrecisionmachinisT wrote:

"Michael A. Terrell" wrote in message
m...

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is "
VFD
question "

It doesn't matter, since the transformer goes before anything
else.
It operates at line voltage, and in Gunner's case at a constant 60
Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the
three
phase current, not the single phase current.


Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?


Because in the case of an RPC, the entire downstream bus in all
probability
has excessive voltage imbalances when measured phase to phase and even
even
a few percent of voltage imbalance has a very profoundly negative effect
on
motor temtrature rise and energy losses to core heating....

Are YOU that stupid?


Sigh. Are you saying that you will adjust each transformer as you
change the load?


Sigh....

What I'm saying is to balance the RPC output voltage first and THEN apply
power factor correction on an as-needed basis at each individual load.

--

On May 12, 11:56*am, Cross-Slide wrote:
On May 12, 10:41*am, rangerssuck wrote:





On May 12, 11:14*am, "Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

* *It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

* *Why would you put three after the RPC when one at the input ddoes it
right? *Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

* *OK, if a hack job pleases you.

A "hack job" utilizing parts you already have on hand vs. spending money
buying new parts will please most HSM folks. We are talking HSM here,
not in a factory where you would have real three phase power anyway

Wait! You're both right! But, I just re-read the original post. Gunner
doesn't make it clear whether the overvoltage alarm is coming from the
mill or from the VFD. If the latter, then you'd have to make the
adjustment on the single-phase input. If the former, you could do the
adjustment on either end, depending on what transformers you have on
hand.

For the eleventh time... You cannot use transformers on the output of
a VFD !

I'm gonna give that an "it depends." If the VFD is only being used to
generate 3-phase from single-phase and the frequency stays more-or-
less at 60Hz, I don't know why it wouldn't work. Of course, you
wouldn't want to use 60Hz transformers at 20Hz (or at 400Hz), but at
60Hz, why would it be a problem?

"Pete C." wrote in message
ster.com...

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP
is " VFD
question "

It doesn't matter, since the transformer goes before anything
else.
It operates at line voltage, and in Gunner's case at a constant
60 Hz.

It does matter, a set of transformers can most certainly come after
a
RPC, if you only have buck transformers large enough to handle the
three
phase current, not the single phase current.

Why would you put three after the RPC when one at the input ddoes
it
right? Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

OK, if a hack job pleases you.

A "hack job" utilizing parts you already have on hand vs. spending money
buying new parts will please most HSM folks. We are talking HSM here,
not in a factory where you would have real three phase power anyway.

Even within a factory environment it is perfectly sound engineering to
parallel transformers.

Fact is, this is very commonly practiced at the utility substation as well
as individual customer distribution levels.

http://tinyurl.com/3bfr3ay

http://www.icmiinc.com/News.htm

Much of the residential distribution in the city of Campbell River, Canada
for example is tied together at the secondary voltage level with
triplex....240vac--there are literally hundreds of pole tranformers all
coneccted to a same triplex buss....with a transformer mounted to every
third pole or so depending on the actual number of houses per block.

--

On May 12, 4:14*pm, "PrecisionmachinisT"
wrote:
"Pete C." wrote in message

ster.com...







"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP
is " VFD
question "

* *It doesn't matter, since the transformer goes before anything
else.
It operates at line voltage, and in Gunner's case at a constant
60 Hz.

It does matter, a set of transformers can most certainly come after
a
RPC, if you only have buck transformers large enough to handle the
three
phase current, not the single phase current.

* *Why would you put three after the RPC when one at the input ddoes
it
right? *Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

* *OK, if a hack job pleases you.

A "hack job" utilizing parts you already have on hand vs. spending money
buying new parts will please most HSM folks. We are talking HSM here,
not in a factory where you would have real three phase power anyway.

Even within a factory environment it is perfectly sound engineering to
parallel transformers.

Fact is, this is very commonly practiced at the utility substation as well
as individual customer distribution levels.

http://tinyurl.com/3bfr3ay

http://www.icmiinc.com/News.htm

Much of the residential distribution in the city of Campbell River, Canada
for example is tied together at the secondary voltage level with
triplex....240vac--there are literally hundreds of pole tranformers all
coneccted to a same triplex buss....with a transformer *mounted to every
third pole or so depending on the actual number of houses per block.


Indeed, a few years ago they replace all of the pole transformers in
my area. B\Nobody lost poer during this operation, as they are all im
parallel - primaries and secondaries.

The reason for the swap (and this did require shutting off thje power
for about 15 minutes) was the new transformers had switchable
primaries. They changed from the existing 8KV to 13KV, which saved
them over half of their I2R losses in the HV cable. They brought in
over 200 bucket trucks to throw these switches. It was quite a sight.

The net result, as far as it concerns me, is that my power has been a
rock-solit 117V, where it used to often drop as low as 95V, and now I
don't have that incessant clicking and clacking from the undervoltage
trip in my UPSs.

"Pete C." wrote:

"Michael A. Terrell" wrote:

PrecisionmachinisT wrote:

"Michael A. Terrell" wrote in message
m...

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is "
VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.


Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?


Because in the case of an RPC, the entire downstream bus in all probability
has excessive voltage imbalances when measured phase to phase and even even
a few percent of voltage imbalance has a very profoundly negative effect on
motor temtrature rise and energy losses to core heating....

Are YOU that stupid?

Sigh. Are you saying that you will adjust each transformer as you
change the load?

No, I'm saying you use what you have and if you have three small
transformers that will do the job after the RPC, you use those instead
of buying a new transformer.


So, you are going to use them on the output to protect the load, but
not the VFD or the RPC?

What good will they do on the output, if the three phase motor in
your RPC is saturating and smoking, or on fire?


You do know that if the three transformers are identical, they can be
run in parallel?


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

PrecisionmachinisT wrote:

"Michael A. Terrell" wrote in message
...

PrecisionmachinisT wrote:

"Michael A. Terrell" wrote in message
m...

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is "
VFD
question "

It doesn't matter, since the transformer goes before anything
else.
It operates at line voltage, and in Gunner's case at a constant 60
Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the
three
phase current, not the single phase current.


Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?


Because in the case of an RPC, the entire downstream bus in all
probability
has excessive voltage imbalances when measured phase to phase and even
even
a few percent of voltage imbalance has a very profoundly negative effect
on
motor temtrature rise and energy losses to core heating....

Are YOU that stupid?


Sigh. Are you saying that you will adjust each transformer as you
change the load?


Sigh....

What I'm saying is to balance the RPC output voltage first and THEN apply
power factor correction on an as-needed basis at each individual load.


And overvolt the RPC motor? Not very smart, is it?


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

Cross-Slide wrote:

On May 12, 12:34 am, "Michael A. Terrell"
wrote:
"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

OK, if a hack job pleases you.

--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

Remember ......... This multiple transformer idea was in response to a
VFD Question.
A VFD Question ... GET IT?

The original question was about a VFD.
The response was to add transformers to the output.

Do not expect to make it into a sensible discussion. It will not
happen.


Certainly not on this newsgroup, where most posters think 'Ohm's law'
is merely a rough guideline and that the laws of physics don't apply to
them.
--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP is " VFD
question "

It doesn't matter, since the transformer goes before anything else.
It operates at line voltage, and in Gunner's case at a constant 60 Hz.

It does matter, a set of transformers can most certainly come after a
RPC, if you only have buck transformers large enough to handle the three
phase current, not the single phase current.

Why would you put three after the RPC when one at the input ddoes it
right? Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

OK, if a hack job pleases you.

A "hack job" utilizing parts you already have on hand vs. spending money
buying new parts will please most HSM folks. We are talking HSM here,
not in a factory where you would have real three phase power anyway.


The OP has a problem with a VFD with an overvoltage condition on it's
input. Please explain how your hack job on the output will fix that.


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

PrecisionmachinisT wrote:

"Pete C." wrote in message
ster.com...

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP
is " VFD
question "

It doesn't matter, since the transformer goes before anything
else.
It operates at line voltage, and in Gunner's case at a constant
60 Hz.

It does matter, a set of transformers can most certainly come after
a
RPC, if you only have buck transformers large enough to handle the
three
phase current, not the single phase current.

Why would you put three after the RPC when one at the input ddoes
it
right? Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you have
for example three 1KVA transformers on hand but no 3KVA transformers,
it's a pretty easy choice to use the three you have downstream rather
than buy a new transformer to use upstream.

OK, if a hack job pleases you.

A "hack job" utilizing parts you already have on hand vs. spending money
buying new parts will please most HSM folks. We are talking HSM here,
not in a factory where you would have real three phase power anyway.

Even within a factory environment it is perfectly sound engineering to
parallel transformers.


Three transformers on the individual phases isn't 'parallel'.


Fact is, this is very commonly practiced at the utility substation as well
as individual customer distribution levels.

http://tinyurl.com/3bfr3ay

http://www.icmiinc.com/News.htm

Much of the residential distribution in the city of Campbell River, Canada
for example is tied together at the secondary voltage level with
triplex....240vac--there are literally hundreds of pole tranformers all
coneccted to a same triplex buss....with a transformer mounted to every
third pole or so depending on the actual number of houses per block.

--


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

"Michael A. Terrell" wrote in message
m...

PrecisionmachinisT wrote:

"Michael A. Terrell" wrote in message
...

PrecisionmachinisT wrote:

"Michael A. Terrell" wrote in message
m...

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the OP
is "
VFD
question "

It doesn't matter, since the transformer goes before anything
else.
It operates at line voltage, and in Gunner's case at a constant
60
Hz.

It does matter, a set of transformers can most certainly come after
a
RPC, if you only have buck transformers large enough to handle the
three
phase current, not the single phase current.


Why would you put three after the RPC when one at the input ddoes
it
right? Are you that stupid?


Because in the case of an RPC, the entire downstream bus in all
probability
has excessive voltage imbalances when measured phase to phase and even
even
a few percent of voltage imbalance has a very profoundly negative
effect
on
motor temtrature rise and energy losses to core heating....

Are YOU that stupid?


Sigh. Are you saying that you will adjust each transformer as you
change the load?


Sigh....

What I'm saying is to balance the RPC output voltage first and THEN apply
power factor correction on an as-needed basis at each individual load.


And overvolt the RPC motor? Not very smart, is it?


You ****ing moron--do I have to spell out every last detail ?

--just a couple posts ago I told you about voltage imbalance and its effect
on motor heating....which is a WAY more serious situation than is running
20% or so above ( or below nominal ) with BALANCED voltages.



1) Balance the converter, generally, capacitors are used.

2) Transform the output if needed ( notably, most 3ph transformers have taps
which allow for a slight buck/ boost adjustment on a per-phase basis )

3) Apply power factor at each load, if needed....

But since it's apparent you're just arguing for arguements then I'm done
with it now goodbye TROLL

--

"Michael A. Terrell" wrote in message
m...

PrecisionmachinisT wrote:

"Pete C." wrote in message
ster.com...

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

"Pete C." wrote:

"Michael A. Terrell" wrote:

Cross-Slide wrote:

Maybe YOU are talking about an RPC, but the subject of the
OP
is " VFD
question "

It doesn't matter, since the transformer goes before
anything
else.
It operates at line voltage, and in Gunner's case at a
constant
60 Hz.

It does matter, a set of transformers can most certainly come
after
a
RPC, if you only have buck transformers large enough to handle
the
three
phase current, not the single phase current.

Why would you put three after the RPC when one at the input
ddoes
it
right? Are you that stupid?

I'm not stupid, but you may be if you are that clueless as to the
context and the point I made about the transformer sizing. If you
have
for example three 1KVA transformers on hand but no 3KVA
transformers,
it's a pretty easy choice to use the three you have downstream
rather
than buy a new transformer to use upstream.

OK, if a hack job pleases you.

A "hack job" utilizing parts you already have on hand vs. spending
money
buying new parts will please most HSM folks. We are talking HSM here,
not in a factory where you would have real three phase power anyway.

Even within a factory environment it is perfectly sound engineering to
parallel transformers.


Three transformers on the individual phases isn't 'parallel'.

Oh I see....and the moon is made of cheese, too....


You can't fix stupid.

Certainly seems true in the case of YOUR stupidity.

--