Ask The Trades - Print Page

Ask The Trades
https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> power tools tripping rcd https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1404148609 Message started by Natedog on Jun 30^th, 2014, 6:16pm

Title: power tools tripping rcd
Post by Natedog on Jun 30^th, 2014, 6:16pm

I'm the shed I've got a small-ish old Clarke wood lathe (a cwl6 if that means anything to you) and an old 6" bench grinder.

Both of them will sometimes trip the main rcd in the fusebox. With the lathe, it's roughly once every 6 or 7 times you turn it on. Don't use the grinder often enough to have spotted any pattern.

Anyone care to have a guess why they do this?

And it's not the shed wiring, coz there isn't any. They run on a long extension from the living room. Other power tools (bandsaw and table saw) don't do it.

Cheers

Title: Re: power tools tripping rcd
Post by CWatters on Jul 1^st, 2014, 7:04pm

I'm not an electrician but...

Is it an RCD or RCBO (combined RCD and MCB)?

Long leads can cause excess voltage drop. This can cause some types of motor to draw more current. which might trip out an MCB.

or could just be damp causing the RCD (earth leakage detector) to trip out. If it is the RCD tripping out then this could indicate a potentially dangerous fault so don't ignore it.

Using extension leads for this is definitely not recommended. You should seriously consider getting a proper supply installed.

Title: Re: power tools tripping rcd
Post by londonman on Jul 2^nd, 2014, 7:13pm

Im guessing they are both induction motors? I'd put money on the starting capacitor being a little leaky.

Title: Re: power tools tripping rcd
Post by Natedog on Aug 12^th, 2014, 11:08pm

yes, i know using an extension lead isn't an ideal solution, but due to the distance from house to shed, digging a suitable trench to bury a supply cable in is prohibitively expensive.

no idea if they have induction motors or not. haven't been able to use my lathe as the drive belt broke and i havan't got round to sourcing a replacement. need to pull everything out of the shed to put in a new workbench that i scored off freecycle, so i will pull the covers off the lathe at the same time and have a looksee

Title: Re: power tools tripping rcd
Post by londonman on Aug 16^th, 2014, 5:10pm

When it's running if it sounds like a knackered vacuum cleaner then it's not induction !