O/T Period Tumbledryers

[FamilyWiggs]

Ok, so I have a tumbledryer that is tripping the RCD that protects all the power circuits in the house, as well as the MCB for the circuit it is on. It trips it as soon as the dryer is plugged in and switched on at the socket, regardless of whether the dryer itself is switched on or not.

It is about 3 years old and shows no other signs of damage.

Now that Mr Wikipedia has resolved his differences with Pippa, I am informed that this is most likely to be an earth leakage fault in the appliance. Given that it occurs whether the machine is switched on I think it is likely to be the power supply in the machine rather than anything related to the heating element or motor.

I can live without a tumbledryer, but Mrs FW is complaining it makes her domestic duties more troublesome. 8) I am loathe to buy her a replacement machine if I can avoid it and repair the existing apparatus. Besides, her birthday is not for another month. :wink:

Can anybody advise me of a useful checklist of testing procedures (in phrases I can understand)? I have a multimeter, a pair of rubber wellies, and healthy dose of can-do.

Thanks all.

 

[MdB]

An RCD will only trip due to earth leakage so it looks very much like this is what you have.

Earth leakage is current returning via the earth line so you have a connection from earth through to something connected to live. Not something that you want. With the drier disconnected you may or may not be able to measure this - resistance measurement between earth and live or between earth and neutral. A resistance below 8000 ohms will cause a trip however I would want values a lot larger than this.

However... My best guess would be a short on a heating element to the case. Some cheap heating elements don't have a separate insulator :shock: between the heating element and their mount which is often an metal component connected to the case. The manufacturer relies on the oxide on the heating element to create the insulation. Many cookers are like this (including mine) and I really don't like it. It can't be a good idea.

This dodgy joint will change resistance with temperature and likely at 50Hz AC rather than the DC that your meter measures. This could mean that you won't measure the fault accurately.

 

[Schoolmarm]

Before the electrical boffins arrive, have you tried plugging into a long extension from another socket?

Have you checked the plug carefully? They are all sealed though now I suppose.

 

[Flyfisher]

We rarely use the tumble dryer since we bought a couple of these: http://www.ecoproductsuk.co.uk/listman/listings/l0085.shtml
OK, that's the smug bit out of the way (though they really are very effective - honestly!).

Like MdB, my first thought on reading the topic title was the heating element, but this seems unlikely if the tumble drier isn't actually switched on. I'd expect the only thing powered on when plugged into the mains socket would be a power supply for the control board (unless of course the control board has failed in such a way that the motor/heater relays are always on). But the power supply might be integral with the control board anyway.

If you're happy delving around and unplugging things then it might be worth trying to isolate the fault to a particular board or other sub assembly (usual safety warnings apply, but you know all that!). Just keep unplugging things until the trippers don't trip - bearing in mind that when they don't trip the internal wiring will be live! - but keep notes about what goes where so you can plug it all back together again. :wink:

You might be lucky and find a simple cable fault. Have a good look for any possibility of wires chafing against metalwork. It can be surprising what a few years of vibration can do - though the manufacturers will have hopefully anticipated such things.

Did I mention about being careful?

 

[Feltwell]

keep notes about what goes where so you can plug it all back together again. :wink:

Digital cameras are your friend - well, mine is anyway, it's saved me on more than one occasion when it comes to those "how the hell did that go together?" moments.

 

[FamilyWiggs]

Before the electrical boffins arrive, have you tried plugging into a long extension from another socket?

Have you checked the plug carefully? They are all sealed though now I suppose.

Yes - we have two suppies and meters in the house Only one trips. Have plugged extension lead into the other supply and trips when I plug in the confounded machine.

Will start to pull it apart as suggested my MdB, FF and FW.

Digital camera is also great for checking the central heating F&E tank when you can't actually see into it, because the clearance above is only 3 inches... and other similar underfloor access/observation issues.

 

[FamilyWiggs]

We rarely use the tumble dryer since we bought a couple of these: http://www.ecoproductsuk.co.uk/listman/listings/l0085.shtml
OK, that's the smug bit out of the way (though they really are very effective - honestly!).

Heating's not working too well at the moment either since I flushed it.... colder inside than out mostly!

 

[Schoolmarm]

 

[JohnB]

We rarely use the tumble dryer since we bought a couple of these: http://www.ecoproductsuk.co.uk/listman/listings/l0085.shtml
OK, that's the smug bit out of the way (though they really are very effective - honestly!).

How do you use them if you're tall and have a low ceiling?

 

[FamilyWiggs]

Well, I pulled it apart, cleaned all the dust out and checked each cable for chafing, etc. I also made sure each fishclip was seated securely.

The good news is the machine is working again and Mrs FW can commence on the backlog of washing.

The bad news is I have no idea what the fault was. :evil:

 

[Zebra]

It's obvious what the fault was. It was just attention-seeking! It just wanted you to take it apart and put it back together again. Often find that sorts things out with no other explanation..... 8)

 

[Flyfisher]

Very strange. I wonder if there is a fault inside the mains cable/plug to the appliance and you've cleared it by disturbing the cable during your investigations. The RCCD tripping suggests some sort of intermittent live-to-earth fault, which sounds like a cable/connection problem given that the dryer now working correctly, i.e. motors, controllers, heating elements don't tend to heal themselves very often!

Might be worth gently flexing/twisting the mains cable to see if you can cause it to trip out again. Or just leave it now it's working again and take Zebra's explanation as the cause. :wink:

 

[FamilyWiggs]

Thanks FF - all very puzzling. I checked every cable and twisted each and every way. It was very caked in felty fluff inside, but since it was bone dry I can't imagine this could have provided a route for an earth leak - so can only assume Zebra is right. :roll:

 

[biffvernon]

Ok, so I have a tumbledryer that is tripping the RCD that protects all the power circuits in the house, as well as the MCB for the circuit it is on.

Maybe you've just got a smart RCD and MCB; they understand the silliness of tumble-dryers.

 

[Zebra]

:lol:
I like the idea of your consumer unit casting moral judgements over which appliances you should be using. It might start switching off when it reckons you've watched enough telly, or thinks you shouldn't have another slice of toast.
On the subject of silly appliances though - leaf-blowers! I mean what's wrong with a rake?

 

[LadyArowana]

On the subject of silly appliances though - leaf-blowers! I mean what's wrong with a rake?

Quite agree, like going around the house with a hairdryer moving the dust.

 

[FamilyWiggs]

Ok, so I have a tumbledryer that is tripping the RCD that protects all the power circuits in the house, as well as the MCB for the circuit it is on.

Maybe you've just got a smart RCD and MCB; they understand the silliness of tumble-dryers.

Quite possibly biff - tell you what, since it is so wet outside I'll chuck some more coal on the fire and dry the clothes in front of that. :wink:

 

[worms]

On the subject of silly appliances though - leaf-blowers! I mean what's wrong with a rake?

You are welcome to come round here and show me how I get the pine needles out of my gravel drive with a rake!
And how do you give the bonfire a boost with a rake?
Or blow the dust out of the car?
Versatile piece of kit a leaf-blower...and that is before you switch it to suck mode!

 

[Zebra]

You are welcome to come round here and show me how I get the pine needles out of my gravel drive with a rake!
And how do you give the bonfire a boost with a rake?
Or blow the dust out of the car?
Versatile piece of kit a leaf-blower...and that is before you switch it to suck mode!

Hmmm, I must admit I hadn't considered any of those scenarios. Hat eaten. Dust out of the car - that's actually quite ingenious. I'd always considered that once dust got under the seat it was there forever.

 

[worms]

I'd always considered that once dust got under the seat it was there forever.

I'd have thought a zebra would have known that all the best safari vehicles are blown out, not hoovered!