revtothelimit - motorbike forum

I've recently moved house and am setting up my workshop / garage. I have a Tormach mini lathe which is a 110V US version similar to the Clarke and other versions on sale in the UK and I power it via a 230v/110v site type transformer. This worked fine in my previous house which had antique wiring with fuses and no RCD.

The new house however is fitted with RCDs and I find that sometimes (but not always) when I power the transformer up it trips both the local one in the garage and the one in the house that supplies the garage. I believe this is because of an initial current surge to the transformer.

Any wise people here who can suggest a solution?

Just a few suggestions until a qualified sparks pops by.......

1) Do ALL the circuits go through the rcd ? Some older units left one circuit off the rcd to avoid tripping " freezer " problems . A bit of swapping may cure ?

2) A sparks could install a live fused spur thus avoiding the rcd ?

3) Is it the transformer or the lathe that is causing the trip ? ( Try the transformer without the lathe connected ) . A large capacitor across the problem device may alleviate the problem ?

If in ANY doubt , use a sparks !!!!!!!!!

1: Yes, all are RCD protected. Too safe!
2: Probably easier (and cheaper) to buy a 230 volt motor......
3: I've tried both and it seems to happen whether or not it's connected. For some reason it doesn't happen every time I connect it.

I suspect 2 above is going to be the real solution although I may have to change the lathe control board as well.

And I totally agree with your last point!