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?
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).
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.