Problem with 3 phase electric motor?
#1
Member
Thread Starter
Problem with 3 phase electric motor?
Hi everybody,
So a while ago I bought a 3 phase motor, which I know would like to wire for 220V
The problem is, I've noticed after opening it up, is that 3 of the wires seem to have been cut (see pictures), or at least, something about it looks wrong.
Am I right in assuming that to get the motor started, I'm going to have open up the motor completely and exchange the cut wires with new ones?




So a while ago I bought a 3 phase motor, which I know would like to wire for 220V
The problem is, I've noticed after opening it up, is that 3 of the wires seem to have been cut (see pictures), or at least, something about it looks wrong.
Am I right in assuming that to get the motor started, I'm going to have open up the motor completely and exchange the cut wires with new ones?





Last edited by PJmax; 05-09-19 at 10:28 AM. Reason: cropped/resized pictures
#2
Unfortunately we aren't going to be able to help you from just the pictures. There should be a wiring diagram on the wiring cover. If not...... you'll need to look up the make and model of the motor from the plate. If there is no plate.... the motor may be scrap.
#4
Is your three phase service...... star or delta ?
Your motor looks to have four wires coming out of it. That would be normal..... 3 phases and a neutral. It looks like for some reason the wires were cut from the crimped lugs and reinstalled under nuts.
Your motor looks to have four wires coming out of it. That would be normal..... 3 phases and a neutral. It looks like for some reason the wires were cut from the crimped lugs and reinstalled under nuts.
#6
Member
I am assuming this is an induction motor. Based on the connection diagram in photo 5, there should be 6 wires from the motor field windings attached to the connection block. This is 2 wires per winding (phase). One end of each winding is missing from the connection block. The motor will have to be disassembled to see if the 3 winding ends are available to attach a wire for connection to the connection block. If available, the ends can be identified with a winding using an ohmmeter. Assuming the bar attached to the 3 lugs in the connection block is a shorting bar, for the neutral connection of a 3 phase wye power source, it must be removed before using the ohmmeter. Opposite terminals on the connection block (rows of three) must be connected to a different winding and its correct end to insure a proper rotating magnetic field. I have never done this and if someone else on the forum can’t help, you will need to have a motor repair shop make the winding connections to the connection block. Based on power source being a delta or wye, add jumpers and power at the connection block based on connection diagram. If winding ends are not available, I would think the cost of rewinding washes with the cost of a new motor. Good luck.
#7
I thought I saw three colored wires and a white.
Makes me think they combined the wires inside the motor.
Do you have an ohmmeter ? Check between the three wires on the posts for continuity.
Makes me think they combined the wires inside the motor.
Do you have an ohmmeter ? Check between the three wires on the posts for continuity.
#8
Member
Thread Starter
If its not too complicated, then I'm fine doing it myself, but if it has to be repaired professionally I would rather just try to return it.
Do you think I would be able to manage to make the winding connections myself?
Do you think I would be able to manage to make the winding connections myself?
#9
Agree with Beelzebob and Pete. It would help to have closer pictures of the wires that are connected to terminal block. A description of the number of wires connected and their colors could also help.
The motor nameplate shows 380/220 so a delta connection of the windings would be needed for 220V. That requires access to all 6 ends of the three windings to make the proper connections.
The motor nameplate shows 380/220 so a delta connection of the windings would be needed for 220V. That requires access to all 6 ends of the three windings to make the proper connections.