REWIREING A NEW MOTOR ON A LATHE Ask questions and find answers to many subjects relating to electrics and electrical work

[maxcorrigan]

Brand new to this forum my problem is i need to wire in a new CROMPTON capacitor start 3/4 HP motor on a lathe this has three terminals connection Z2 and U2 U1 being Neutral and Live. The BROOKE GRYPHON MOTOR it is replacing has four connections A1 A2 Z1 Z2 all of which are in use and wired in to a DEWHURST Type A reversing drum type switch, can anyone tell me laymans terms how i can do this? possibly with a diagram (if needed) using the same Dewhurst switch, already in place on the lathe
I have tried to get various electricians round to sort this out but they either don't know or don't want to know! that is if they turn up at all
so here's hoping i can get help on this forum
Regards Max..............[/b]

[ericmark]

A1 - A2 would normally be main windings U1 - U2 is another marking for same thing Z1 - Z2 is the start winding and reversing these will reverse motor some times non reversing motors will only have one start winding connection which it would seem is the case with your motor. As to exact wiring you will have to follow what came with the motor as there are many configurations on single phase motors some have capacitor permanently connected and other use some form of start switch or combination. Those made by Brook Crompton which don't require a switch will have PDA in the type number somewhere. Those needing a start switch or button normally have EDA or TDA in the type number. The use of this type of motor has in the main been replaced with three phase motors now using a inverter which converts the 230 volt single phase to 230 volt three phase with speed variation as well. Most small three phase motors are 230 volt delta wired and 400 volt star wired so can be run with ease on a single phase supply. As a result electricians don't come across many single phase motors any more. Especially for lathes where some soft start is an advantage. Brook Crompton web site does have pdf documents available on general wiring. So I think you have wrong type of motor but without details that come with motor hard to be certain.

[maxcorrigan]

[quote="ericmark"]A1 - A2 would normally be main windings U1 - U2 is another marking for same thing Z1 - Z2 is the start winding and reversing these will reverse motor some times non reversing motors will only have one start winding connection which it would seem is the case with your motor. As to exact wiring you will have to follow what came with the motor as there are many configurations on single phase motors some have capacitor permanently connected and other use some form of start switch or combination. Those made by Brook Crompton which don't require a switch will have PDA in the type number somewhere. Those needing a start switch or button normally have EDA or TDA in the type number. The use of this type of motor has in the main been replaced with three phase motors now using a inverter which converts the 230 volt single phase to 230 volt three phase with speed variation as well. Most small three phase motors are 230 volt delta wired and 400 volt star wired so can be run with ease on a single phase supply. As a result electricians don't come across many single phase motors any more. Especially for lathes where some soft start is an advantage. Brook Crompton web site does have pdf documents available on general wiring. So I think you have wrong type of motor but without details that come with motor hard to be certain.[/quote]

Eric thanks for your reply to my query i have been advised by somebody on the isle of man that that the two internal leads Z2 and U1 to be disconnected and reconnected too R and S terminals this then will take the fourth wire and provide reverse motion this man has bought the same motor that i have and has it up and running so hopefully i will get the same result once i figure out where each wire goes!!
Thanks for your help anyrate Max..........