Running a 4 kW motor

[ban-all-sheds]

I have nothing new to add.

Indeed you don't.

I wonder if you think that repeating that often enough will make people forget that what you have nothing new to add to was an untrue allegation?

Kind Regards, John

Hypocrite.

 

[JohnW2]

I wonder if you think that repeating that often enough will ...

Nope, and I'm not going to repeat it any more in this thread.

Kind Regards, John

 

[dave1w]

Doing a bit of googling 220V 3 phase is found in US in smaller domestic applications. It’s a big country so I imagine there could be a lot.

 

[ban-all-sheds]

Are you absolutely sure that you have found reference to 220V 3-phase in smaller domestic applications, and not 220V split-phase?

http://www.ccontrolsys.com/w/Electrical_Service_Types_and_Voltages​

and:

The most common supply systems in the USA are probably.

Single phase, 3 wire, 120/240 volt. Common for detached homes and small businesses.

Three phase, 4 wire at 208/240 volt. Commonly used for apartment blocks and smaller business premises. Each flat or apartment typically served with two phase and the neutral. All three phases the norm for a business.

Three phase 4 wire at 277/480 volt. Not permitted domestically but popular for larger offices and for factories.

Three phase delta with mid point of one phase grounded. 120 volts between the grounded neutral and the ends of the winding that has the grounded centre tap.
240 volts between any phase and any other .
208 volts between the grounded neutral and the other phase. This phase is known as the "wild phase" and should be identified by orange marking.
Sometimes used domesticly so as to permit of a three phase central air conditioner and the usual single phase 120/240 volt loads.
DANGER some old services of this type may NOT isolate the wild phase by the opening of the main switch !

Three phase delta, ungrounded, floating.

Three phase delta, corner grounded, one phase is grounded and therefore three phase loads need only TWO pole switches, fuses and breakers, rather than the three pole devices needed for normal 3 phase.

Also be aware that some LV three phase supplies are derived from 3 phase MV by use of just TWO single phase transformers rather than the three that would be expected, this saves the cost of one transformer.
Such supplies are known as "open delta" The capacity of a two transformer open delta transformer bank is 57% of a three transformer bank, and not 66.6% as one might expect.​