Thread: VFD (?) tripping RCD
Left the spindle on for about an hour last night. It was fine. Just been using the lathe for quite a while and no problems there. So the former implies it's not the spindle and the latter implies it's not. That or it's nothing to do with the VFD.
I'm going to try it once more as normal, then if that fails I'll use an extension lead.
[*]Measured the voltage above with the spindle running, same result. If I disconnect the earth wire I get 180VAC between frame and earth...so I didn't do that for long!
something to do with filters in the VFD providing a path to earth - which then trips the RCD
Try measuring the leakage current of the VFD on its own. If that is the problem connect it via a separate, lower sensitivity RCD but make sure your earth bonding is good!
Last edited by russell; 27-11-2011 at 01:50 PM.
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It might help to try and replace the mains rcd, i had the same problem with the house main fuse popping all the time(through the night also) it turns out that after a couple of times the main rcd was too sensative,all fuses are ment to be changed after a couple off trips.(told by an electrition)
Update... worked for a long long time running the lathe and coolant pump in parallel (machining stainless). Long enough for the cast iron headstock to warm up a bit.
Failed after about 3 minutes on the router, but this time only the VFD, circuit breaker didn't trip. I just got the 'ELuS' error... I've only had an error before on the VFD when I've been getting a bit carried away on the lathe and overloaded it (so not often).
I'm going to buy another VFD now as I could do with having two anyway as then I can run the lathe and router at the same time. I think I'll get a 3kW one as the lathe plus pump is borderline on the 2.2kW. It will help diagnose the problem, though I hope to have sorted it by then.
Just a thought Jonathan But
Have you checked your water pump and pipes ?? on the router
would it help if I came with my VFD at the weekend to try ??
make sure your RCD is rated at 30mA and NOT 100mA. Around 50mA can kill with the correct fault path through your body, which I think is from your left hand through your body to right foot then to ground.
have you checked for rodent damage ??
as you are away from your work shop in the week rodents will get in and chew cables (just a thought)
has your water pipe got a blockage if a filter is fitted it my be blocked, is the water flowing around your motor ??