OT:- Trippin mains - Electricity gurus in da house?

This sort of question is often well answered on uk.d-i-y,

I suspect you need to say what type of circuit breakers they are. Typically heating elements have some leakage to earth, so they trip some of the current comparing type as they leak a bit.

AJH

and an overheated support can char and leak more current.

Steve

It sounds like an (the) RCD that is tripping, does it incorporate a little 'test' button too?

RCD's are, on the whole, a major PITA.

AJH is correct with uk.d-i-y

Hi Lee, circuit breakers are for short / overload protection RCD's are for shock protection ( generally ) The main switch you talk about, are you sure it is an RCD does it have a push to test button on it if so it is an RCD and this would indicate a fault with something, are you sure it is the tumble dryer ? does it trip out every time you switch it on if so then there is probably something wrong inside, could be element, noise filter where mains comes in to dryer, also motor, all are possible. Hope this helps.

I've got a turbo diesel :-) Rich

Rich uttered summat worrerz funny about:

Oh snap I've got a TD too!

Yes it has a test button on it and once it's switched off it kills the supply to the whole house.

Pretty certain it's the Tumble dryer, if it's still switched on some times the trip wotsit won't reset, switching it off at the mains though ensures it resets. Never happens when the tumble dryer is off.

I did think it could have been an overload previously as the Tumble dryer , washing machine and Kettle had all been on on previous occasions (Mrs D can multi-task!) but tonight only the Tumble dryer was on and again would not reset until the power to the Tumble dryer was off altogether. ... would go now, no doubt there will be £50 off in January, BUM!

I'll bung a post on uk.wotsit - so many NG's :-)

Lee D

Do you know someone with an insulation resistance tester ( megger ) you could trace the fault with it ??

I need an intercooler :-( Rich

It sounds like you have an earth leakage problem. I suspect it will either be the motor or the heating element.

Whole house RCDs are a real pain. I had a problem with my electrics and we would wake up in the morning with the whole house in darkness!

You can get RCBOs which are individual RCDs for each circuit, you are then allowed to fit a less sensitive RCD on the whole house. This means that just the circuit causing the problem trips, not the whole house.

OK, I'll fix your house, can you fix my LT77 gearbox in return :-)

Cheers

Peter

Unless of course the dryer has electronic trickery to control it which the megger will fry unless used carefully.

no doubt there will be £50 off in January, BUM!

I refuse to let my wife have one, they gobble a lot of electricity. If she had one it would be used 100% of the time, irrespective of a heatwave.

It's the washing line on dry days and the maid-aid in front of the kitchen range when it's wet.

Julian.

Not a major help, but don't forget to consider that the tumble dryer is plugged into one socket all the time (I assume). Thus, it may be that the socket is the problem, not necessarily the dryer.

Run the dryer on another socket (or plug something else into the tumble dryer socket) and compare the results. Easy enough to pull the faceplate and check that all looks well inside.

HTH

Tim Hobbs uttered summat worrerz funny about:

Yep, will explore further tomorrow when I can knock the mains off without causing mass hysteria to the 'ickle peeps. Tis in the garage so could well be a spider in the socket having a bad day.

The down side is I've got to do the washing to check it out, perhaphs Mrs D should have a sickie...... OUCH

;-)

Lee D

damp or condensation can cause it to trip too, the lights in the garage used to trip the rcd when they got damp

On or around Thu, 07 Dec 2006 19:14:41 GMT, "Julian" enlightened us thusly:

so's being electrocuted, mind.

RCD = residual current device, which used to be called and ELCB = earth leakage circuit breaker.

as may be, earth faults can trip it. typically, it'll trip on 30mA in the earth.

Residual current I think describes the fact that the live current and netural current don't match, as some of it is going astray. when the bit that's going astray is going through you, you'll be glad of the breaker.

The ordinary kind of MCB (Miniature circuit breaker, I think) which are often fitted to individual circuits trip only on overload, typically a rign main will have 32A ones.

If you've isolated the fault to the tumble drier then get it checked; if it's a new fault (i.e. wasn't doing it before) chances are there's summat wrong with it.

On or around Fri, 08 Dec 2006 09:10:50 +1300, EMB enlightened us thusly:

exactly what I were thinking.

I've got a megger - 250v DC one...

and scroll down a bit...

Sort of. AIUI the ELCB has given way to the RCD. They do work in a different way because the RCD just looks at current in neutral and live - if they differ by more than 30mA (in your case) then it trips, current in the earth conductor isn't a factor with an RCD.

The trouble is that lots of devices in the home use high value resistors between live and ground for RF suppression, and these currents throughout the house are cumulative, and the RCD thus becomes 'hair trigger'

There is just as much chance that it's just some dampness in the thing, it's been very wet indeed round here of late, there could be nothing wrong at all. Also, if you unplug all the other devices that use resistors between live and earth for RF suppression (Sky digiboxes etc) then the chances are that the dryer will no longer trip the RCD.

I've got a twin to that somewhere in my shed, and a newer one (sans crank handle) that I actually use.

Only to be used between live and earth or neutral and earth why else would you want to test between live and neutral when it's and earth fault you are trying to find ????

Rich

On or around Thu, 07 Dec 2006 22:04:19 GMT, "Rich" enlightened us thusly:

Modern meggers apply 500V though and could make for over-voltage on the electronics.

I certainly does sound like an RCD that is tripping.

It could possibly be damp in the dryer, espicially if the vent to outside is blocked or it is venting into the back of the dryer. Try running the dryer empty to dry things out.

The other prime suspect is the mains filter in the dryer. The capacitors can become 'leaky' and draw excessive current. You could by-pass it as a test and see if the tripping stops. It should be easy to spot it will be the first thing the mains comes to in the dryer. It will be a metal case with a ground connection and inputs and outputs for line and neutral. Usually 3 or

4 inches long and rectangular or sort of tubular in shape and usually silver in colour. If you do by-pass it don't leave it like that, get a new one and put it in, otherwise spikes could get everywhere.

Usual warnings about playing with mains voltage electricity apply, also the capacitors in these filters can store some charge and give you a belt even when unplugged, so it is best to short each connection to ground to make sure it is discharged; after disconnecting from the supply of course.

regards Jeff