2 speed Pole changing motor Circuit 1.5kw

[joel89]

Hi all, I have got to build a small panel for a overhead crane long travel drive motors (Old Street crane) The motor is is a 2 speed pole changing motor 750rpm and 1500rpm it needs both slow and fast speed and it also has a link between across 1ph of the slow and fast winding in the motor terminal boxes.

I am guessing this isnt a standard 4 contactor method (slow, fast, fwd, rev) I have been told I may need a pole changing contactor? anybody got any drawings of a reversing pole changing circuit?

Cheers

 

[cliffed]

Sounds interesting,go to kenwood motors site,there are some good ideas there.
At the moment trying to find 2 speed controller for a 4 pole motor.

 

[Andy-1960]

I believe this is called a Dahlander starter, a few years since I've done one of these!

 

[joel89]

thats good i need reversing too, i would imagine i could add FWD & REV contactors in before the mains then feed the other contactors? and that is a 6 wire mines five ive never come across this type of circuit before

 

[Andy-1960]

Yes you can put another pair of contactors upstream to reverse.

I used to do the starter above by putting K1 in the middle with K2 and K3 on either side, you can then put mechanical interlocks between K2 - K1 and K1 - K3.

 

[cliffed]

Well done ,interesting stuff,love it

 

[joel89]

spoke to a crane electrician today, they use 5 wire to avoid using 4 contactors and 6 wires.

2 contactors fwd + rev and pole changing contactor 2 phase NO/NC. cheating way of doing it really