Customer Transformer Specs.

We have specified that a customer needs to supply a 208Y 4 Wire 3 Phase 50 Amp connection to our machine.

His reply was that his electrician will install a 240 Volt, 12-208, 45KVA transformer.

I understand the 45KVA, but what does he mean by 240 Volt, 12-208 and will that supply the configuration I need.

I apologize in advance, but I am a little behind when it comes to power distribution jargin. (Programmer by profession)

Did he mean 120-208?

Somebody dropped a zero. It's 240 input, 120/208 output. To get 3 phase, they use 3 transformers on the inside. The electrician will be able to connect these in a 'Y' configuration like you want.

Don't worry, everything is okay.

Oops, I should have figured that out. Thanks guys.

Somebody dropped a zero. It's 240 input, 120/208 output. To get 3 phase, they use 3 transformers on the inside. The electrician will be able to connect these in a 'Y' configuration like you want.

Click to expand...

The above statement implies that you can get 3 phase power from a single phase input by using 3 transformers. The last time I studied this subject, it was impossible the convert 1-phase power to 3-phase with any number of transformers. However, it is possible to do with a "phase converter", which is a horse of a different color.

If going from 1-to-3 phase was as simple as 3 transformers, there would not be numerous companies building phase converters:

http://www.isomatic.co.uk/3phConverterSelection.htm

Probably the input is actually 240 volts 3 phase, and the customer is supplying a 240 volts primary, 208/120 secondary 3-phase transformer.

Your are correct in that the customer now has 240 volt 3 phase in the building and will be installing a transformer to satisfy our machine requirements.

We used to hang large transformers on our machines to get the correct configuration, but now we are leaning towards having the customer supply the correct configuration.

We are a custom machine builder and I am curious if this is an industry trend?

I work in the Semiconductor Manufacturing Equipment industry. The facilities people would rather supply their own power. Supplying transformers, etc. means they have to incorporate 'foreign' parts into their distribution, and then be responsible for it.
In may cases, it works out cheaper for the customer if they supply their own. The person buying your machine thinks it's proper to insist you make the machine conform to his power, but doesn't realize this is not what the Facilities people prefer.
We rarely need to supply transformers after explaining typical Facilities preferences.