Simphoenix JGD-80 ER20 2.2kw 40000rpm

Hi chaps,

I'm looking for a little help with a VFD. I have a 220v Simphoenix e550 2.2kw single phase vfd - brand new along with a 40,000 rpm atc.

I can run the spindle and vfd fine when the spindle isn't grounded.

If it is grounded it trips my RCD/GFCI. I cannot bypass the rcd. The problem is the machine is grounded. If the spindle is fitted to the machine that in turn grounds the spindle which in turn kills power to our building.

The vfd was setup by the supplier on shipment. Originally we thought it might be the spindle but we changed that out and it made no difference.

I've read the manual, contacted the supplier and manufacturer and am at a loss.

Manual: https://purelogic.ru/data/docs/elekt..._manual_ru.pdf

Does anyone have any ideas?

You could try a new RCD, I'm not sure if they have higher rated versions like they do MCB but you could ask. We often have trouble with In-rush tripping MCB's when using VFD's but we just change them out for a "D" rated type and it fixes the issue. I suspect you could have something similar going on but with RCD.?

After that then it very much sounds to me like the spindle is shorting to ground and that's why it's tripping the Residual current device. You have Earth leakage and if it doesn't happen when the spindle isn't grounded then to me it must be the spindle.

Edit: I use have an ABB VFD which as a Screw in the side for EMC filter grounding and when fitted it does the same and trips the RCD. Does it have anything like this.?

If only it was that easy. The RCD is right after the meter, we'd need to get the mains disconnected at street level to swap it out safely.

I thought the same thing. The spindles run in at around $1500 usd, bought another after discussing it with the manufacture and they tested this for ground leakage too. Same deal. There are allot of articles online about vfd's triggering GFCI's due to the frequency.

Ermm not good maybe try another make of VFD but if it's the Incoming side that is too sensitive it will probably happen again.? . . You may just have to bite the bullet and get that sorted.! . . . .Sorry, I can't be of more help.

I found this article https://www.precision-elec.com/wp-co...zGc6o7L15ZxGvq

In that it suggests setting a higher starting frequency and changing the acel/decel times.

With nothing to loose I tried it and set starting freq to 15, acel and decel to 1 second.

I was able to start the spindle and did not blow the power....

I also took some measurements and there is 0.1mv of leakage, and whilst I can't check the range can see a spike on startup.

We have some other things running in the background so this could be a fluke. It is interesting though.

Quote:

---

Originally Posted by Mr*Beaver

I found this article https://www.precision-elec.com/wp-co...zGc6o7L15ZxGvq

In that it suggests setting a higher starting frequency and changing the acel/decel times.

With nothing to loose I tried it and set starting freq to 15, acel and decel to 1 second.

I was able to start the spindle and did not blow the power....

I also took some measurements and there is 0.1mv of leakage, and whilst I can't check the range can see a spike on startup.

We have some other things running in the background so this could be a fluke. It is interesting though.

---

Yes, it's not uncommon to have to play with settings sometimes to stop VFD from faulting, esp when using heavy tools or loads, I had it recently with an ATC spindle and had to play with settings which were different to what was recommended to get it to work reliably but it's not common to trip the MCB. It usually just throws an error code in the VFD.

I suspect you might still hit trouble when underload or heavy startup.?

Yep, I had been through the settings a couple of times which is a little frustrating. There wasn't any load but it seems to be working.

I did error trip it on decel, think it's time to order some more bits... braking resistor.

I had a similar problem when I commissioned my machine (Sunfar VFD driving JGH-85 spindle); the RCB tripped out about 40% of the time when switching the control box on with the VFD isolated and 100% of the time with the VFD switched on. I did a lot of prodding and poking and the issue seemed to be the EMI filters and the capacitors to ground therein. If you're switching the mains with a mechanical double pole switch, the 2 poles don't make at exactly the same time, so for a short instance you're connecting a cap from one leg (L or N) to ground = current imbalance = trip out. The only sure-fire way I found to solve it was changing the RCD for a type F device which also handles HF current draw to boot which should solve any problems when running. Strange that your RCD is straight after the meter, surely there's a master fuse in circuit? If so a qualified sparky would be able to legally pull that to change the RCD thankfully I have a good mate who is one :-)