I recently bought a milling machine with a 3hp motor. I purchased a
7.5 hp rotary phase converter and hooked it up to my mill. I have a
100 amp 220 service to my house. Unfortunity I have noticed that when
I first turn the mill on the lights in my shop quickly dim due to
starting of the mill which I understand. My problem is my electric
line is shared with my neighbor then goes to the transformer on the
pole. Another neighbor is also hooked up to the same transformer and
everytime I start the mill the neighbors lights also dim quickly...My
question is due you think I should get the power company to fix the
problem? Do I really need to get a bigger service (200amp) even
though I am only running one machine?

Thanks

wrote:
I recently bought a milling machine with a 3hp motor. I purchased a
7.5 hp rotary phase converter and hooked it up to my mill. I have a
100 amp 220 service to my house. Unfortunity I have noticed that when
I first turn the mill on the lights in my shop quickly dim due to
starting of the mill which I understand. My problem is my electric
line is shared with my neighbor then goes to the transformer on the
pole. Another neighbor is also hooked up to the same transformer and
everytime I start the mill the neighbors lights also dim quickly...My
question is due you think I should get the power company to fix the
problem? Do I really need to get a bigger service (200amp) even
though I am only running one machine?
The simplest thing would be to get a VFD, which can slow-start
the motor. I don't get any blink of the lights when I start my
7.5 Hp lathe!

Putting in a 200 A service may not cause the power company to replace
the transformer, depending on its current size.

Jon

Someone else told me about them but are they very pricey? Where could
I get them?

When I start the phase converter it dims for a second but when I
operate the mill thats when the light dim for the neihbors. Its really
noticable that I need to do something about it. I also notice when I
do turn on the mill, the converter growns alittle, like theres alot of
power being used. I sometimes wonder maybe its the converter?

Another question would be should I use a VFD unit instead of the rotory
phase converter? From what I can tell ,I can ramp up the spindle speed
of the mill and would not get that surge.

He already has that, he was asking about VFD.

--

Clif Holland KA5IPF
www.avvid.com


"Ignoramus408" wrote in message
...
On 12 Nov 2005 17:28:16 -0800, Carbonite wrote:
Someone else told me about them but are they very pricey? Where could
I get them?


you could make your own

http://igor.chudov.com/projects/Phase-Converter/

--

On 12 Nov 2005 16:49:06 -0800, wrote:

I recently bought a milling machine with a 3hp motor. I purchased a
7.5 hp rotary phase converter and hooked it up to my mill. I have a
100 amp 220 service to my house. Unfortunity I have noticed that when
I first turn the mill on the lights in my shop quickly dim due to
starting of the mill which I understand. My problem is my electric
line is shared with my neighbor then goes to the transformer on the
pole. Another neighbor is also hooked up to the same transformer and
everytime I start the mill the neighbors lights also dim quickly...My
question is due you think I should get the power company to fix the
problem? Do I really need to get a bigger service (200amp) even
though I am only running one machine?

Thanks

You probably want to talk to the local power utility before you do
anything - they probably need to put in a larger transformer at the
pole to handle the start surge of that big a motor, when combined with
the normal loads of the other houses on the same transformer.

It's also possible that there is a dirty connection or two in the
high voltage lines coming into the common transformer, or on the low
voltage side where you and your neighbors all hook up. They can send
a lineman up there with a voltmeter to look for bad connections.

And another probable source of the problem is the service drop wires
to your house. It is common for utilities to chat rather ruthlessly
on the voltage drop of service wires - you install 1/0 TW Copper wires
up the old mast for a 100A service to allow a bit over the mandated
minimums, and they use #2 XLPE Aluminum service wire up to the pole.
Sure, there's a lot of voltage drop in the circuit from that service
wire, but they're the utility and they can do it - and save some money
on wire in the process.

Myself, I'd change the main service and riser to a 200A Copper-buss
service panel as the first step, to minimize any voltage drop problems
that may be in your equipment - and if your old panel is over 20 years
old, it's probably due anyway.

If you've done any major square- footage additions to your house,
you might even jump a notch to a 400A service, then when you get that
great deal on a Lathe you are still OK.

(I have to do that myself - bump up from an old 200A fused-switch
main service to a 400A. But I've already reworked the main breaker
panel, the 200A was a bit oversized when it was installed, and we've
converted the kitchen, water heater and clothes dryer from Electric to
Gas to ease the load. See "Shoemaker's Children Go Barefoot...")

Most home builders make the main panel as small as possible to save
money, a 100A or 125A panel, or a 70A "Crowfoot" (six breakers, no
Main) in the older days. And then over the years you've gone and
added on one or two bedrooms and a Den, and central air conditioning,
and a big swimming pool/spa with a 1.5 HP filter pump and a 2 HP spa
booster, and a microwave oven, and a toaster oven, and that big-screen
entertainment center, and a computer and laser printer...

The conversion of your garage into a home shop with the upgraded
lighting, and the fans, and the 7.5 HP rotary phase converter and 3 HP
mill, and the 50A welder outlet - that's just the last nail in the
coffin. If this sounds a lot like your house, I can guarantee that
you need to upgrade the main service.

Make sure that you generously oversize all the wires - use 4/0 or
250MCM Copper for the 200A mast riser where 3/0 THHN would do, and
oversize the wires heading into your shop sub-panel and the phase
converter the same way.

The Electrical Codes are a /minimum/ standard - there's no rule at
all against doing a better job than you have to. ;-)

And get the utility to use the right sized riser wires to the pole,
too - they'll grumble about it, but if you twist their arm you can
probably get them to break out the 250MCM or 350MCM Aluminum wire.

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.

This doesn't sound right to me. Talk it over with the power company and
see if you can get them to check the situation out.

Steve

Carbonite wrote:

When I start the phase converter it dims for a second but when I
operate the mill thats when the light dim for the neihbors. Its really
noticable that I need to do something about it. I also notice when I
do turn on the mill, the converter growns alittle, like theres alot of
power being used. I sometimes wonder maybe its the converter?

I read a number of the other posts and don't disagree with any of them.
But since your neighbors get the dimming, too, I'd go to the utility
company right away. You are going to have to do that sooner or later
anyhow.
We live out in the country where we have our own transformer on the
pole.
Some years ago we replaced an old farmhouse with a new house and
installed a 200 amp breaker box with "400 amp" leads to the pole. Three
years later on a hot summer day, we were holding a power hammer
rebuilding workshop and the power went out. I called the utility co.
and they came out right away. Reset the breaker on the pole and told me
"gee, you sure are pulling a lot of power. You are drawing 54 amps on
one leg and 57 amps on the other!" (To which I said "Sure sounds like I
have 'em well balanced.")
I told 'em that 55 amps shouldn't be a problem since I have a 200
amp service that is almost new that they recently hooked up to.
----Now, HERE comes the point:
They said --- 'yeh, but we never install transformers big enough to
handle the max load from your main box. We always assume that you only
got that big box so you'd have a lot of extra breakers!!!"
So, if your utility co. used that reasoning and if they did it 20
or 30 or 40 years ago, it's quite likely that the whole neighborhood is
underpowered.

By the way, they removed my old 5 or 7.5 KVA transformer and installed a
10 or 15 KVA and no troubles since.

Pete Stanaitis

wrote:
I recently bought a milling machine with a 3hp motor. I purchased a
7.5 hp rotary phase converter and hooked it up to my mill. I have a
100 amp 220 service to my house. Unfortunity I have noticed that when
I first turn the mill on the lights in my shop quickly dim due to
starting of the mill which I understand. My problem is my electric
line is shared with my neighbor then goes to the transformer on the
pole. Another neighbor is also hooked up to the same transformer and
everytime I start the mill the neighbors lights also dim quickly...My
question is due you think I should get the power company to fix the
problem? Do I really need to get a bigger service (200amp) even
though I am only running one machine?

Thanks

If you are pullng down a neighbor, it's the power company's problem.
Best bet is to have the NEIGHBOR call the power co and ask them to
install (temporarily) a line voltage recorder. Then run the mill on a
series of heavy cuts. 3 minutes on, 2 minute off, etc. Nice square wave
forms on the recorder will get their attention.

Keep in mind that 2 or 3 volts variation is considered 'normal' by the
power co. You might want to get a good voltmeter, plug it in at the
neighbor's place and see what readings you get.

wrote:

I recently bought a milling machine with a 3hp motor. I purchased a
7.5 hp rotary phase converter and hooked it up to my mill. I have a
100 amp 220 service to my house. Unfortunity I have noticed that when
I first turn the mill on the lights in my shop quickly dim due to
starting of the mill which I understand. My problem is my electric
line is shared with my neighbor then goes to the transformer on the
pole. Another neighbor is also hooked up to the same transformer and
everytime I start the mill the neighbors lights also dim quickly...My
question is due you think I should get the power company to fix the
problem? Do I really need to get a bigger service (200amp) even
though I am only running one machine?

Thanks

I looked into a VFD for my mill but decided against it. Part of the reason
was expense (the spindle motor is 10hp so a VFD is lotsa $$) but the main
reason was that all the information I could gather said that the VFDs didn't
like to ramp up one motor and then ramp up another. My table drive motor is
3hp, so after the spindle is going I'd need to turn on/off the table drive,
plus there's a light and a coolant pump. I still need to build a rotary
phase converter for this machine..... this winter for sure.

al.



"Carbonite" wrote in message
oups.com...
Another question would be should I use a VFD unit instead of the rotory
phase converter? From what I can tell ,I can ramp up the spindle speed
of the mill and would not get that surge.

In article ,
says...
This doesn't sound right to me. Talk it over with the power company and
see if you can get them to check the situation out.


It would be worth checking on the power company's policies
before calling attention to yourself. Our local power
company (Central Maine Power) reserves the right to refuse
service to single phase motors and phase converters larger
than 5HP. I've never heard of it happening, but presumably
there's a reason for the provision in the tariffs - perhaps
so they can avoid spending money to upgrade long rural
feeds that are approaching their capacity.

Ned Simmons

I remember one time asking about having a 3 phase line put in, its
about 1/4 mile down the street where 3 phase power is. They told me
about $25,000 to put it in and recommended phase converter.

I was told by someone that they will put a meter on the line and check
for voltage drops. I talked to a person that sells phase converters
and he can't believe that I am pulling more than 100 amps from my
service. We will see, I will keep on there backs for sure.

On Sun, 13 Nov 2005 18:24:14 GMT, "Al MacDonald"
wrote:
"Carbonite" wrote in message
roups.com...

Another question would be should I use a VFD unit instead of the rotory
phase converter? From what I can tell ,I can ramp up the spindle speed
of the mill and would not get that surge.

I looked into a VFD for my mill but decided against it. Part of the reason
was expense (the spindle motor is 10hp so a VFD is lotsa $$) but the main
reason was that all the information I could gather said that the VFDs didn't
like to ramp up one motor and then ramp up another. My table drive motor is
3hp, so after the spindle is going I'd need to turn on/off the table drive,
plus there's a light and a coolant pump. I still need to build a rotary
phase converter for this machine..... this winter for sure.

Consider two VFD's or rotary converters - one sized for the spindle
motor, one for the table drive motor. Better than trying to kludge it
to make one VFD do both, which probably can't work anyway.

The work lights and the controls can easily be converted to a
separate 120V or 120-208/240V single phase power feed - the lights are
more than likely either incandescent or fluorescent. The only tricky
part is integrating any automation controls on the mill with the
outboard VFD's, but you can do almost anything with a little
forethought.

The coolant pump is more than likely oversized for the load and can
use a static converter, or you build a small rotary converter, or
change the stupid pump motor out to a single-phase.

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.

Ned Simmons wrote:

In article ,
says...


This doesn't sound right to me. Talk it over with the power company and
see if you can get them to check the situation out.




It would be worth checking on the power company's policies
before calling attention to yourself. Our local power
company (Central Maine Power) reserves the right to refuse
service to single phase motors and phase converters larger
than 5HP. I've never heard of it happening, but presumably
there's a reason for the provision in the tariffs - perhaps
so they can avoid spending money to upgrade long rural
feeds that are approaching their capacity.

Ned Simmons


Yipes. I'll keep that in mind for future complaints (being in Maine).

Steve

Update on my phase converter problem. I called NYSEG and they came out
and said that the transformer on the pole was too small. I guess I was
accually hooked up to two other houses on the same transformer. On top
of that the neighbors used to have 100 amp services and upgraded to 150
amp services. Wether that made a difference or not we will see. The
power company ask for my loads and ask about the neighbors service.
They are putting in the new transformer and larger wire for free. I
will keep my 100 amp service and they said I was within my service.
Thanks everyone for responding, I will let you all know what the
outcome is.

Steve