Wire size for 200A Subpanel

[mm08822]

This is the machine:

https://www.haascnc.com/machines/vertical-mills/vf-series/models/small/vf-2ss.html

It’s nominally a 30HP spindle but it’s widely understood that Haas rates their spindles at a 200% intermittent capacity level, so the rating is extremely generous. Many people run off single phase in home shops and the 20HP Phase Perfect seems to be the most popular option.

I have a number of people on Practical Machinist saying they run these on as little as a 50A single phase breaker feeding a converter. I don’t doubt them. I just don’t know how much of a dice roll it is. For the money entailed I would want a pretty decent assurance.

So you need to go to mfr and get data that represents your machine. 100 options doesn't narrow anything down.
Also, get their knowledge on phase converters used.
Details for the whole electrical job revolve around this. Undersizing would be the worst, but oversizing wastes money and could be unnecessary grief with POCO.

 

[Viper98912]

Learned something new from this thread, thank you to everyone

 

[35Ford]

One thing you don't want are any surprises for anyone. All the information on the machining center, phase converter and other loads should be included in your service request to National Grid. If they know what you are planning on doing, all that information will be required.

 

[ipgenie]

I was not aware of a hp limit when I bought a 10hp 240v air compressor about 15 years ago. It was a sweet deal I couldn't pass up even though it was oversized for my needs.

Our meter is on the shop and feeds the house. I noticed that the lights in our house dimmed slightly when the compressor started. There are three properties on the transformer on our pole. I asked one neighbor if they had noticed their lights dimming and they said no, but they work out of town and are not home much so I'm not sure weather it affected them or not.

We installed 25kW solar about 5 years ago and the next year there was a short that caught the pole on fire. I talked to the serviceman who is a neighbor who lives about a mile away. He said they replaced the pole and up sized the transformer and no more lights dimming. There are no properties close enough to use our pole so we should be fine moving forward. The serviceman told me that the 10hp compressor should have been approved by the poco but said don't worry about it now.

 

[Metal-Marc]

What do you mean by this?

You have to get into imaginary numbers for that.

 

[sansbury]

You have to get into imaginary numbers for that.

I prefer the irrationals myself.

 

[Metal-Marc]

I prefer the irrationals myself.

It's getting Complex.

 

[BlindViper]

Guess its good thing I am on my own transformer with my 20 hp rotary phase. Power company didnt seemed concerned when I did my 400amp heavy up on the house.