A quick question, what supply voltages are available in the USA for industrial users?

Everybody at work is telling me that the US system uses 120v per phase so 120v single phase and 240v three phase.

Now I am sure that I saw 400 or so volts on various panels when i worked in the Timken steel plant in Ohio for a short time.

is this just my imagination or is 415/440v three phase available (to industry etc)

I always thought it was 110V with a centre earth, i.e. live = +55V and neutral = -55V. It is the safe voltage dangerous current philosophy.

I believe that domestic premises get 2 phases - use 1 phase at 110v for general stuff, 2 phases at 220v for heavier stuff like cookers. Hence the reason why USA folk keep saying that it's easy to make 3-phase converters - yes it is, when you have 2 phases available to begin with!

Unsure about industrial premises (so no real answer to your question! )

Like above

Domestic is 120 V AC 60 Hz

Larger domestic is 240 V 2phase 60Hz ( with neutral to give 120 v ac)

Industrial 240V 3 phase 60 Hz

RD

hmmm, well put it another way.

We are currently looking at buying up to 6 used 65Kw to 125Kw 3 phase extruders from the USA and are trying to budget the costs of converting them to run in the UK.

A bit of internet research has confirmed that the bigger supplies in the USA used in factories etc are indeed 400+ volts, concensus seems to be 480v 3 phase. (which rings a bell from when I was over there)

Its all getting a bit hectic as we have some folks over at the auction today and no clue as to what is required to drive 60 hz unknown voltage kit on 50hz 415volt!!!????

I'd ring the Extruder manufactures...

US do have access to 480v 60Hz 3phase

http://users.pandora.be/worldstandards/electricity.htm#3voltage

I supervised a recent commercial build-out of warehouse space for my sister in laws dance studio. Service there was 480. Electricians installed 480v flourescent fixtures.

Can't help with any specifices though.

T