Part Winding Start

[iggy2]

Contractor is replacing an MCC with new. Two motors (25HP and 7.5HP) are 6 lead motors, with existing part wound starter buckets. The MCC is rated 800A, on a 1600A, 208V 3 ph service.

Can these motors be connected to an across the line starter (i.e. two leads each on T1, T2 and T3)? All info I see is that there is low start torque anyway, and the service is pretty stiff....

Does anyone know what the starting current is reduced to when part winding start?

 

[hpec]

Re: Part Winding Start

Yes the windings can be connected in parallel. Part winding starting reduces the normal starting current to approx. 65%. The starting torque is reduced to 42% of normal starting torque. If you square the percent of current reduction you will obtain the reduced starting tourque.

Hpec