vfd

[tito103]

Can a 6 lead motor used from an old wye - delta starter be wired to a VFD, and how would you wire it. (nameplate data 60hp, 460 volt, 3 phase. lead #'s 1,2,3,7,8,9

 

[davidbeach]

Wire the motor in delta and take the three leads to the VFD. Depending on the age of the motor, the insulation may or may not react favorably to the VFD output. If the motor is fan cooled by a fan on the motor shaft (most likely), you will need to watch what you do with the motor at lower speeds to avoid overheating. In a fan/pump application you may be fine down a ways as the load power will fall off at least as fast as the motor self cooling. An application that may result in a more constant power or constant torque load will probably cause the motor to overheat at lower speeds unless additional cooling is provided.

 

[powerjunx]

tito103,

"..(nameplate data 60hp, 460 volt, 3 phase. lead #'s 1,2,3,7,8,9)"

Tap your motor to VFD as DELTA connection as line1(1&6); line2(2&4); line3(3&5).

In your case; i think it's not 7,8,9; it should be 4,5,6 for a motor having 6 leads out.

A posible drawback when using VFD, the motor winding insulation might not sustain the harshness of harmonic effect produced by VFD itself. Consequently, the winding coating will erroded and will build up tiny pinholes to the extent the coating will detach to the winding and lead to interturn short-circuit faults,etc.