Poly phase transformers

[IAC]

Can anyone help by telling me what the connections are on a poly phase transformer and which connections would be most likely to be used in a factory.

Thanks

 

Delta - grounded Wye is common in North America, especially industrial and commercial systems.

 

[dydt]

In North America and in some countries in Asia, here is some examples of common secondary distribution system via
transformer..

a. Single phase 3 wire....3 wire, 120/240V, 240V branch for power loads and 120V for lighting and receptacles..

b. 3 phase, 4 wire wye system...120/208V, 3 phase 4 wire with neutral grounded

c. 3 phase, 4 wire, wye connected system...480/277V..
277 single phase for some lighting..

d. 3 phase, 3 wire system...this is the common delta connected system with phase to phase voltage of 240, 480 and 600v...in some systems 3 phase 3 wire circuits at 480v fed individual motor loads with single or 3 phase step down transformer, stepping from 480 to 120v used to supply lighting and receptacle circuits..

e. 3 phase, 4 wire delta system...this variation in 3 phase is sometimes called "RED LEG"....one of the transformer secondary windings supplying the system is CENTER TAPPED to derive a grounded neutral conductor...to the two phase legs between which it is connected...

then you have the 380/220v system in europe which you should be familiar with...esp. when you receive or buying a machine from that location....you should be familiar with working around the different system voltages and able to come up with a transformer that will do the job..

there should be some good site or books around that will give you more information on the connections and systems..

good luck..hope this helps..

dydt
toronto