Single Phase motor controled by 3 phase contactor
Single Phase motor controled by 3 phase contactor
(OP)
I have a 120VAC 6amp non reversing motor to control.
I dont know how to wire it to a three pole contactor normally used for a 3phase motor. I have the correct size contactor from the manufacuture's data table for single phase use.(allen bradley 100-C09) Does this mean I only wire one pole? Do I jumper all three pole together?
I also dont know how to size an overload.
Is this the correct way to control a single phase motor in a comercial enviroment?
Thanks for the help.
I dont know how to wire it to a three pole contactor normally used for a 3phase motor. I have the correct size contactor from the manufacuture's data table for single phase use.(allen bradley 100-C09) Does this mean I only wire one pole? Do I jumper all three pole together?
I also dont know how to size an overload.
Is this the correct way to control a single phase motor in a comercial enviroment?
Thanks for the help.





RE: Single Phase motor controled by 3 phase contactor
I.E: your inputs are labelled 1-3-5 and your outputs from the overload are labelled 2-4-6....you would put a link wire between terminals 3 & 6 ...then your supply wires would go to terminals 1 & 5 .....and your motor leads would go on terminals 2 & 4.
hope this helps
Jeff
www.motors-direct.co.uk
RE: Single Phase motor controled by 3 phase contactor
Jeff gives good advice on wiring. From the amps, you're less than one horsepower and obviously automatically started. If for continuous duty, NEC 430-32(c) applies. You size your overload for 125% of nameplate FLA IF it has a service factor 1.15 or greater OR IF marked with a temperature rise not over 40 degrees C. Otherwise, size at 115% of nameplate FLA. Other exceptions might apply too -- IF your motor is thermally protected internally, or impedance protected against overload, you don't need separate overload relays and can leave the overload relay out of the circuit.
If you do need overloads, your local electical parts distributor probably has a chart from his supplier to choose the proper ones. Take in all the nameplate data, including FLA, service factor, and temperature rise.
Let us know what you wind up doing!!
Old Dave
RE: Single Phase motor controled by 3 phase contactor
The NEC worries about safety (could care less if motor gets damaged) and NEMA worries about protecting the motor (with safety in mind as well).
RE: Single Phase motor controled by 3 phase contactor
"Venditori de oleum-vipera non vigere excordis populi"
RE: Single Phase motor controled by 3 phase contactor
I hate learning new stuff at this age...
Old(er) Dave
RE: Single Phase motor controled by 3 phase contactor
Another big confusion is that "SF" applies to HP and not amp draw. If it is "SFA" or similar then amps is applicable. Just thought I would throw that out too.