2 Speed Motor

Good Morning all,

I am doing some work with a 2 speed motor from Brooks & Crompton (It's an older motor, part # not found - UK490-023).

A starter for the motor is being put together, but the unit is in SAf.

On a 2 speed motor, there is 2 sets of windings? Would this mean that in order to start the motor with a enclosed starter you would need 2 contactors/overload relays, one for each set of windings?

Just curious as to how the speeds are typically toggled on these types of motors. I would guess they just have 6 line power inputs - T1,T2,T3,T4,T5,T6...however, are these energized as separate sets, or are they combined for the higher speed?

Thanks in advance,

Hayzed1

I think there are different types of windings in 2 speed motors some are dual wound ie one set of windings for each speed the last one i wired was fed U1 V1 W1 connected to the 3PH line and U2 V2 W2 not connected to run low speed

High speed U2 V2 W2 connected to 3PH line and U1 V1 W1 connected in star

This was achieved by fitting 3 contactors with 1 set of overloads and fitting mechanical and electrical interlocks between the contactors

what is the information on the motor name plate?
y/y, 2y/d, what is the speed ratio? [hige speed/low speed]

If 1 - 2 - 3 ohm out with no reading to 4 - 5 - 6 and 4 - 5 - 6 ohm out you have 2 separate windings, if not and they all ohm together you have 1 winding with 2 speeds. It will make a big difference in how in how the motor is connected to get your 2 speeds.

A starter for the motor is being put together

Click to expand...

How can you build a starter if you don`t know the connection for your speeds? Just a guess, bit i bet it hooks up like davefinic has posted. Here`s some motor info from Ron`s sight that might help?