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Electric company problems

rustedhooks

Plastic
Joined
Sep 26, 2015
Hello all,was just wondering if some has run into this particular problem with the power company as I have.
In the process of adding 2 cnc machines to my shop, a Fadal 4020 with 15hp motor, Okuma ESL10 lathe with 15/20 hp. Have the usual manual machine tools, 16x40 lathe, and small Bridgeport clone, Harig surface grinder. Did all the needed electrical calculations based on max load of the machines, wanted to be able to run at least the 2 cnc's at the same time. So after consulting with an electrician and the guys at Phase Perfect, determined that I needed the PT3110, 40 hp phase converter, and I would need to upgrade my existing 200 amp service to 400 amp. Called the power company to come down and take a look, showed them the data tags from the machines and the PP converter, well get a call from the engineer with power company and he told me that they would not be able to do this because I would pull to much current across thier single phase lines. My shop has its own meter, 200 amp, I am in a rural area, the power company is a co-op. Anyone have past experience in a situation like this?
 
It's entierly possible that your load will cause excessive unbalance, more so If they are a small cooperative and/or are using open delta distribution transformers. Can you negotiate with them for a reasonable price for three phase?
 
I am 5 miles from the nearest 3 phase lines. I could buy another building that has easy access to 3 phase cheaper then I can have it run here....it would be in the 5 figures, possibly 6 figures to get it run 5 miles. I can still run my shop, although only one machine at a time.
 
Having done the phase converter thing years ago, I think you might be surprised
at how little power you can run a machine on, especially the Fadal..

Yeah, its a 15HP motor, 22.5 peak.. But how often are you using that much power??
Probably not all that often...

Where I ran into problems, the lathe... Compared to a 40 taper VMC, spinning up a big
heavy lathe chuck, and big ass spindle, and big ass bearings takes a ton of juice.

I had to set my spindle ramp times out to 5 seconds, and I still couldn't use high gear..
 
I dont think I would ever used the rated power on either machine. I just dont understand why the power company says thier lines would not handle it.
 
How many amps does the 40hp Phase Perfect require? That's plenty of phase converter for your machines!

I am betting your existing 200 amp single phase service will handle the 40hp PP, and thus you don't need to upgrade to a 400 amp service....which is pretty rare for single phase anyway.

A member here, Ox, runs a small factory's worth of manual and cnc machines on a 50hp rotary phase converter.

You have to take the cnc machine's nameplate ratings with a grain of salt - they are rated basically as if every electrical load on the machine is maxed to the limit at the same time. Which never happens....
 
Are you at the end of the line or somewhere else?

The line is probably about maxed out and the co-op doesn't want to fight with the power supplier they buy electricity from over the cost of upgrading the transformers and wires to increase the capacity of the branch you're on.
 
It'll run fine on 200A. Your phase converter is even overkill. The lathe will pull the most when the spindle starts. You could run all that off a 100A breaker. If you don't think so, get a amp meter and monitor the feed to the PP for a while when you are pulling heavy loads.

Edit: Like already said, that nameplate is calculated using max loads for every motor/fan/pump etc. Its way silly. Think what kind of craziness you would be machining to have every axis maxed and the spindle maxed. I use an app FSWizard for picking cutting parameters. Its cool because it shows you theoretical HP needed and tool loads etc. Example, for a 1" EM, 1" deep, .5" stepover, 694rpm, 16 in/min in 304SS (for me this would just be stupid cutting) its a 12HP cut.
My thought is that its probably more relavent to look at the actual HP needed to do some types of cutting, and what your tools can take. Get a feel for what your machine will actually be pulling under various real world cutting.
 
Well it seems the engineer at the electric co-op MISREAD an email from his consultant, as I got a phone call late Friday afternoon telling me I was approved for the 400 amp service.
 
Good for you!

Some years ago when we were looking to buy our building we had our electrician come in as we needed 3 phase power.
Electrician went to power company, told him what was needed. Power company came down looked everything over and said no problem...my electrician made sure to get that in writing.
We bought building, ran the electric service, poured a concrete floor, brought in the machine from out old place...all ready for service the power company is called, they send down a crew...they look it over and say" No, we are not running 3 phase here. "

At first our jaws dropped, but then my electrician said not to worry...just figure out what you spent on building, upgrades, moving and what you make when running and send the power company your bill...each month till they give you power. Reps from power company got a bit interested as electrician pulls a signed commitment for service.

Long story short...power company does what they want...sort of.
 
Well it seems the engineer at the electric co-op MISREAD an email from his consultant, as I got a phone call late Friday afternoon telling me I was approved for the 400 amp service.

Glad to hear its working out. Ran into kinda the same issue here. Had to drop a particularly large transformer ( and attending cost ) to run new service to my shop for my Puma 300L. As others have stated, the nameplate ratings are with everything running 100% etc. I went to another shop to run current tests on their Puma 300 and it spiked at like 70A when ramping up. Run was like 15-20A . Nonetheless the power co-op required service to the nameplate, along with usage estimations based on FLC. Yeah...... $1500 deposit to connect ( estimated usage like $500/mo ) and $4300 for transformer and to drop a pedestal 10' from pole. Last bill was $140 and I ran it hard and long ...
 
My professional machinist friend and mentor down the road from me has been machining for 35 years now. He went to CNC some 15 years ago and has a lot of other machines that use 3 phase. (2 Monarchs, two CNC;s, two Bridgeports, Drill presse, etc. ) Back when he moved in all of his machines, he asked the local electric company if he could get three phase power for them. They sent out an engineer who made some notes and he got it approved in a week. The cost? Free for the hookup. He's had 3 phase ever since. All the engineer wanted to see was whether he had enough machines to warrant the company pulling a line in 100 yards to his shop! Man have things changed now. It wolud cost you big money nowadays to get 3 phase. The OP should probably forget buying lottery tickets. He's used all of his luck getting 400 amps! LOL.
 
Why are US power companies so reluctant to supply three phase? For 50% more cable from the substation and the same number of poles, they can transmit 73% more power. They also get a network that's far easier to balance and is more resiliant to faults. Surely any farm of more than a couple of hundred acres and any business with more than a couple of machines is a candidate for wanting a three phase supply. Let alone offices and stores with large A/C and lighting loads?
 
I am 5 miles from the nearest 3 phase lines. I could buy another building that has easy access to 3 phase cheaper then I can have it run here....it would be in the 5 figures, possibly 6 figures to get it run 5 miles. I can still run my shop, although only one machine at a time.

Well, that sucks, but its just how it is man. I think several here including me have had to pony up.

However if you have a 200A service why are you calling them? Just run it.
 
I have been thinking along the same lines. The 400a services I see are actually one meter socket with 2- 200a disconnects. Have you seen any that are just one big 400a service? I am not ready to do this yet but for mine I was thinking the 30hp phase perfect which as I recall wants 200a. Put this on one 200a disconnect feed my 3phase panel which is currently fed by a 30hp american rotary. Then feed my 200a single phase panel with the other 200a disconnect.
 
Why are US power companies so reluctant to supply three phase? For 50% more cable from the substation and the same number of poles, they can transmit 73% more power. They also get a network that's far easier to balance and is more resiliant to faults. Surely any farm of more than a couple of hundred acres and any business with more than a couple of machines is a candidate for wanting a three phase supply. Let alone offices and stores with large A/C and lighting loads?

Uhm, some of our single phase is just a single wire up there on the poles.

Three phase, I see 3 wires, sometimes (4) (for a 277 to ground customer).

If your sending 3 phase to every customer, you have to make sure all (3)
wires are intact. With single phase you only have to maintain that one, single
wire.

I'm just not seeing your point, maybe our electricity distribution mannerisms
are different ?

I did notice, in Chile and Argentina, even residential areas have 3 phase
pole xformers. (and a single box at that, not 3 units on one pole)
 
In the US single phase power to most residential / non 3 phase buildings is on two lines. Its actually 2 120V lines so that you can combine them and get 240V single for larger household items like clothes dryers, air conditioners, etc. So in that case its just one extra line to get 3 phase. Thats also how the phase converters work - the first two phases just pass through the converter - the 3rd phase is "manufactured" by the phase converter.

To the OP - I would buy the 40hp Phase Perfect, hook it up, and then see how many amps you are pulling. I have the 20hp which PP will tell you needs a 110A breaker. I have it running my Hurco VM10i (15hp) just fine on a 70amp breaker. If I add another machine on that line like a compressor or something I might need to upgrade that, but I doubt it. The PP units only need a few extra watts to run their circuits and account for some loss, unlike rotaries which have alot of parasitic loss.

Now - if the electric company is running the new 400A lines for free, well, then by all means do it!
 
No help what so ever
Over here you have 3 phases everywhere in the street Underground No above ground lines Only the really high voltage transport lines are above ground
But here we use the star system that gets you 240 volts from any of the phases and the star point
while the potential difference between phases is 400 volts
Some domestic houses have 3phase comming in Some single phase Depending on time of install and regent But if you ask for 3 phases you get it without any hassle
The higher amps will cost you money though in service costs But that is the same for everyone
I downgraded from 3x63 amps to 3x32 amps It saved me more as €1000/year


Peter
 








 
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