Bosch WTA4007GB/01 tripping RCD

[kazgaz]

Hi everyone

Got an old Bosch dryer in our shed which was tripping the main split RCD in our 10yr old consumer unit. The element was knackered so I replaced it for a new one which worked perfectly for around 15 mins. It's just tripped the RCD again and continues to do so immediately after I try to start it again. I've replaced the plug and tried running an extension lead from the kitchen to the dryer and the same thing is happening.

My missus wants a new dryer now as this one is older than my teenage son. We'll probably get a new one but my curiosity is wanting to know what could be possibly causing it to trip the RCD. Next culprit could be the motor. How would I test this?

As ever, thanks in advance!

 

[PrenticeBoyofDerry]

Does the RCD trip only? Does the RCD trip when plugged in only or when you press the on button?

 

[jj4091]

Disconnect & insulate the wires to the element then try the machine again, you may well have been sold a duff one. If it still trips the next thing would be to check the wiring looms & control boards for rodent damage or other infestations (with it being in a shed ). I doubt it is the motor as they are brushless induction motors so it would have to be awfully damp to trip the rcd.

 

[kazgaz]

Does the RCD trip only? Does the RCD trip when plugged in only or when you press the on button?

Hi, the RCD on the consumer unit trips after around 10 to 15 minutes after the dryer has started. Once it trips and I reset the RCD and trying to start the machine again it trips instantly.

Disconnect & insulate the wires to the element then try the machine again, you may well have been sold a duff one. If it still trips the next thing would be to check the wiring looms & control boards for rodent damage or other infestations (with it being in a shed ). I doubt it is the motor as they are brushless induction motors so it would have to be awfully damp to trip the rcd.

Hi, I've checked all of the cabling for rodent damage and there appears to be none. I did think I may well have been sold a duff element, but I removed it again and I am getting continuity through the element and an ohms reading of around 20 ohms. Does this mean the element is ok?

Sorry for the delay in replying, been away camping the last couple of days whilst the weather was nice.

Cheers.

 

[jj4091]

Not necessarily, if it is the insulation of the element is breaking down when hot it will probably short to earth ( the body of the element) & you will not be able to test that with a multimeter. Once it has tripped disconnect & insulate the leads to the element & try again. If it is faulty it should not then trip instantly but will probably come up with an error code instead because the element is no longer heating.

 

[PrenticeBoyofDerry]

The element is favourite to be the issue, you say RCD trips after about 15 minute in. Once the the RCD trps and you reset, then turn appliance straight back on again how long before the next trip?

There are other components that could be responsible, such as thermostat and the motor, but we need to eliminate the element first.

 

[kazgaz]

The element is favourite to be the issue, you say RCD trips after about 15 minute in. Once the the RCD trps and you reset, then turn appliance straight back on again how long before the next trip?

Hi PrenticeBoy, machine trips straight away after I reset it.

Not necessarily, if it is the insulation of the element is breaking down when hot it will probably short to earth ( the body of the element) & you will not be able to test that with a multimeter. Once it has tripped disconnect & insulate the leads to the element & try again. If it is faulty it should not then trip instantly but will probably come up with an error code instead because the element is no longer heating.

There are over components that could be help reasonable, such as thermostat and the motor, but we need to eliminate the element first.

Hi jj4091, it looks like it is the element. I disconnected it and the dryer ran for a full 90 minute cycle. Back to the supplier on flea bay I think?

Thanks a lot for your assistance guys, very much appreciated!

 

[jj4091]

Personally I think O.M. elements are a false economy.

 

[kazgaz]

Personally I think O.M. elements are a false economy.

Your probably right jj4091. Over the 13 years I've had the dryer I've replaced the element three times, so I'm not doing too bad. I've had earache from the Mrs and we've decided to bite the bullet and get a new dryer.! 13 years from a dryer I think is not too bad!

Thanks again.