Hi Kevin, looks like it has been bodged up a bit and it isn't as safe as it should be as the NVR contactor is missing. Below are scans of the circuit diagram. The first two show how the forward/reverse lever makes the connection ditto on SB3/nrn-20 on a single phase motor and the second two shows the same on a three phase motor.

I'm guessing that QF1 may also be missing which is an overcurrent protection.

Regards Nick.

Edited By Nicholas Farr on 09/04/2015 21:07:01

Hi Kevin,
The motor is definitly a single phase motor. IF NO CONNECTIONIONS AT THE REVERSING SWITCH HAVE BEEN CHANGED FROM THE ORIGINAL WIRING then removing the two straps in the motor connection box leaving the existing wires connected to U1 and U2 and connecting the two black wires that have been cut off to terminals V1 and Z2 (Middle top and bottom right) should work. Before trying this can you confirm that the motor runs forward with the reversing switch in both forward and reverse positions and that in the middle of position the motor is stopped. (Assuming there is a middle off position.) I have just read your comment about the mains being connected directly to the reversing switch. In view of this I agree with Nick that you need a competent person to re wire it as in the diagram so you have the NVR function and the interlocks working.

PS I've Just realised why there are two diagrams for single phase operation. One shows the path through the reversing switch for forward. The other shows the paths for reverse.

Les.

Edited By Les Jones 1 on 09/04/2015 23:06:37

Hi Kevin,
Either the wiring on the reversing switch has been changed or the motor has been connected to one of the pair that should go to the main winding (2 and 10 on the reversing switch if it is wired as in the diagram) and one of the pair that would go to the auiliary winding (4 & 6 for one of the wires and 8 &12 for the other wire on the reversing switch if it is wired as in the diagram) Does your lathe have an electrical box containing the contactor (KA1 on the diagram) and the thermal overload unit (QF1 on the diageam) ? Also does it have the start and stop buttons and the interlock switches ? I think you need to get someone on site with electrical knowledge.

Les.

Hi Kevin,
You need an electrician with a knowledge of motors or someone like a number of members of this forum with reasonable electrical knowledge. Not just an electrician that can only wire houses. It is possible that the box with the start buttons and contactor have been removed. It is also possible that it was never fitted. If the panic button is the latching type and the contacts rated high enough for the motor current it could have been wired without the stop start buttons and contactor. From some threads on this forum I think some Myford lathes just had a Dewhurst reversing switch without any NVR unit or thermal overload. My lathe (Chester DB10G) was not fitted with thermal overloads.

Les.

Hi Kevin and Les, as far as I'm aware all Warco 220 lathes came with the contactor box wired in. The photo below shows this box situated at the right hand end of the splash back.

The Warco 220 is the same as the Mashstroy 210T and the emergency stop is wired integral within the lathe itself and can be seen at the right hand end of the bed. I think at some time in its past, the contactor box had developed a fault and someone has just removed it and put a plug on the end of the flex that went into the box. Peter G. Shaw did a write up in MEX 192 of how he repaired a fault on his own Warco 220 lathe contactor box.

Regards Nick.

Hi Kevin, if you can check all the connections as Les has suggested, I think you will find they are all correct as I've studied your photos again and they look to be right, but you do need to make sure.

In the meanwhile and this may help Les more than yourself, I have been able to lift the cover on mine and your connection block is not all that different. The links shown in my diagram, have not be used in the wiring.

In the photo below the block is designated as follows, from top left to bottom right and reading left to right. W1 V1 U1 # V2 U2 W2

Mine also has two capacitors, but I don't know their values, but one is physically slightly smaller. The larger one comes in though the top grommet on the right hand side and the smaller one comes through the bottom grommet on the right hand side. The wiring coming in from the left hand side is from the forward/reverse.

I'm sure yours can be corrected from all this info, but I do agree with Les that you really do need an NVR for safety reasons as much as anything else.

Regards Nick.

Edited By Nicholas Farr on 11/04/2015 10:45:41

Hi Kevin,
Have you identified and labeled the 4 wires in the motor connection box ? If so here is the next task to confirm that the reversing switch is working as it should be. You need to create a table for each of the three positions of the reversing switch to indicate which of the mains plug pins that each of the 4 wires ( A, B, C, D) connect to.

Somthing like this

Forward

A ?
B ?
C ?
D ?

Middle (off)

A ?
B ?
C ?
D ?

Reverse

A ?
B ?
C ?
D ?

You will replace the question mark with either L (Live), N (Neutral) or NC (No connection)

When I have confirmed that the results of these tests are as expected I will tell you how to connect the 4 wires to the motor terminals.

The tests that you have done so far confirm it is wired as in the diagram Nick posted. (Apart from the strarter being removed)

Les.

Nick,
The diagram in Kevin's motor makes it very clear how to wire it up.

Les.