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Posted By: splitzapper ph 3 wire delta to supply 3ph 4 wire y - 01/24/05 06:22 AM
hello there. the electrical utility that serves our place supplies a secondary of 240/208v 3ph,4 wire Delta.will it be ok if a 4 wire, y motor be supplied by this? is it safe if i put the common wire of the motor on the ground wire of the delta supply? What would happen if i do this?

thanks again.....
Posted By: pauluk Re: ph 3 wire delta to supply 3ph 4 wire y - 01/24/05 02:42 PM
Is the motor designed for a wye connection to 120/208 volts?

You won't be able to connect directly to the 4-wire delta (the high leg will be 208V to neutral, and the phase angles will be wrong anyway).
Posted By: JBD Re: ph 3 wire delta to supply 3ph 4 wire y - 01/24/05 02:49 PM
The utility supply voltage is probably 240/120 3 phase 4 wire delta.

The internal construction (winding arragnement) of a motor is not a factor. all you need to worry about is what external connections (leads) are provided.

If you only have 3 voltage leads (one per phase) then your motor will work fine. If you need 4 wires to your motor (extremely rare) it will not work on your 4 wire delta service.
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