Wiring problems

[martin bakerParticipant @martinbaker81996]

Rewired motor

[martin bakerParticipant @martinbaker81996]

Recently moved premises and dismantled myford super seven for move but on rewiring motor according to my sketched wiring diagram and attempting to turn on the lathe just throws the trip switch on the main power board. I haven’t changed anything I think so don’t understand the problem. I have attached images of the on off switch which I haven’t touched and the inside of the motor. The only wires I have attached are earth/brown to U1/blue to U2 and two black wires to S terminal (one of which I have removed prior to the taking the image) all others are as they were. Can anyone help please. Thank you

 

[Rob keevesParticipant @robkeeves73950]

I would suggest earth and brown are your problems, as you thro the power on you are shorting live to earth, remove the earth there should be a connection on the case of the motor for earth i would suspect. hope this helps.

[Les Jones 1Participant @lesjones1]

Hi Martin,

I do not think the two black wires should go to the same terminal on the motor.

I assume there is a reversing switch on the lathe. If so two of the four wires will go to the run winding the other two will go to the start winding. (I am assuming it is a single phase motor.) When you say it” throws the trip switch on the main power board” do you mean the consumer unit for the house / workshop ? If so do you mean the MCB for that circuit or the main RCD ? If it is the main RCD that trips then there is a fault to earth. If it is an MCB that trips then the lathe is drawing too much current.

(If is a RCBO for that circuit that trips then there is no way to decide if it is an earth fault or over current fault. ) I cannot read the letters against the top and bottom terminals on the motor. Could you say what these are labelled and add a copy of your notes. Do you have a multi meter to help identify the winding in case no one has a lathe with an identical motor to yours ?

Les.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Martin, I agree with Les, that the two black wires probably don’t connect to the same terminal. As they are most likely to be the two used for the start winding as Les says, they probably go to the forward/reverse switch, could it be possible that one of them was on terminal R in your motor photo.

 

One tip I use in these days of digital photos, when disconnecting wires, is to take some photos from different angles, to show clearly where each wire came from. In the example below of my Hobbymat lathe forward/reverse switch, all the wires are white, therefore I removed each wire in turn and slipped a numbered cable marker on them and reconnected them before removing any of the other wires, and then took the photos. The numbers, by the way, just represent the position in the main terminal block that they go to, when reading left to right.

 

Regards Nick.

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