Charnwood W583 issue

[Urga]

I've acquired a second hand Charnwood planer thicknesser, which was working up until I cleaned it and set up the tables. Now it seems to have developed a fault which instantly trips the breakers in my garage and house.
Here is what I have established in trying to get to the bottom of this.
I have renewed the feed cable in case there was a break causing a short. This was jointed just before the internal joint box within the machine.
There is no visible damage to any cable within the machine, and I cannot find any leakage to ground or shorts using the multimeter.
There appears to continuity for all cables tested.
The NVR switch appears to be functioning correctly. I wired the feed cable directly to the NVR and the machine works. However, this bypasses the microswitches and emergency stop, not good.
I have individually disconnected the above switches and connected the cables together to see if that helped the problem. No success, and I am assuming that this means the switches are good? I also tested to ground on all the switch terminals.
My thinking is that if all the switches appear to be working OK, then the fault lies within a cable somewhere? However, I can't detect any lack of continuity or short using my meter?
The motor and capacitor must be fine if it starts(belts removed) when these safety features are bypassed. Hence, my testing of the microswitches and emergency stop button.
I really am baffled by this. The machine seemed to be running fine when I took if off my van, so it must be done to me cleaning and fettling?
Can anyone point me to something I may have overlooked, or maybe have had a similar issue themselves?

Thanks in advance
David

 

[Urga]

A little update, in case anyone is interested.
I rewired all the connections within the joint box with Wagos and managed to get the machine to run, but only when the earths were left disconnected?
Does this point to an issue with the motor? All the earth cables have continuity with each other and I can't detect a short to either the L or N?
Getting there, but still none the wiser

 

[Bingy man]

I’m no expert but it seams that you have narrowed it down to an earth fault . One of the earths are possibly shorting against a live or neautral . The earth s are doing their job and shutting off the supply via the rcd . Not all faults are visible . I think I’d be reconnecting the earths 1 at time until it trips to narrow it down even further . Use extreme caution as no earth is no safety line for you .. hope to his helps

 

[Urga]

I’m no expert but it seams that you have narrowed it down to an earth fault . One of the earths are possibly shorting against a live or neautral . The earth s are doing their job and shutting off the supply via the rcd . Not all faults are visible . I think I’d be reconnecting the earths 1 at time until it trips to narrow it down even further . Use extreme caution as no earth is no safety line for you .. hope to his helps

Thanks for your reply.
I have indeed tried connecting the earths one at a time, resulting in a trip each time.
After further Googling, it appears that the motor capacitors can cause an earth leakage, if faulty. This would cause a trip. Unfortunately I don't have a device that would detect an earth leakage, so maybe will just have to replace the capacitors and hope that they are the cause.

 

[Sachakins]

Worth new capacitor, normally around about £5, so not a bank breaker

 

[MorrisWoodman12]

Can you isolate the caps from ground? Temporarily of course. Possibly give you further info.

 

[Bingy man]

Thanks for your reply.
I have indeed tried connecting the earths one at a time, resulting in a trip each time.
After further Googling, it appears that the motor capacitors can cause an earth leakage, if faulty. This would cause a trip. Unfortunately I don't have a device that would detect an earth leakage, so maybe will just have to replace the capacitors and hope that they are the cause.

Yes they won’t cost a massive amount and with the motor running without the earths then the actual motor is probably ok ..

 

[Urga]

Thanks for the responses. I'll replace the capacitors and update on whether it was successful. Hopefully, if it works, it might help anyone else who encounters a similar problem.

 

[Urga]

Well capacitors replaced (even though I suspected there was nothing wrong with them) to no avail. Still trips the RCD in the garage and the house. So it appears I have an earth problem elsewhere in the machine? Can anyone point me to a resource/person of knowledge on this matter? I'm totally out of ideas as to what to try next.