NEFF S5443 Dishswasher Trips Main RCD

[spectre]

Hi All

Dishwasher gave up the ghost on 24th Dec (merry xmas!). I've had it apart in the past to clear out the pipes in the side panel (this was just to get it

cleaning again properly/remove the gunk). Now as soon as the door is closed (and obviously after the unit is turned on and the program set) it trips the

main house rcd. The unit can be programmed with lights on/door open and remain fine but as soon as the door closes the rcd trips. Any pointers specific

to this make and/or model would be appreciated..

Thanks in advance..

 

[rocks1]

Poss heater fault. Disconnect the wires to heater tape the ends up and see if it trips. If yes do the same with the circulation pump. Then the mains suppressor.

 

[spectre]

Cheers for the reply - I assume then that the heater cycle kicks in immediately (as soon as the door is closed) ? will check each in turn. I was trying to recall (from memory/by sound) if the pump started as soon as said door was shut too.

 

[rocks1]

It completes a circuit once the door is shut. Any earth leakage will trip the supply. Drain comes on after the door is shut sobit tells the brain no water in the base so it will start filling.

 

[spectre]

Cheers again, the short fill hose (I think it's the fill hose anyway) to the front right was full of gunk, and a fair bit of water in the sump - not quite sure how it got there (maybe across the o ring seal if it couldn't get past the gunk and built up to mains pressure). That's all cleared out now. Anyway, a bit of water to underside of motor/pump housing- but when connected to a separate supply across terminals A and B it turned fine and this did not trip the 30mA mains trip (this with the suppressor/capacitor in place so I assume that is fine too) . I assume the heater is the white housing to the right ? - I've removed in turn wires at C,D,E,F,G and also above at H but still it trips as soon as the door is shut. I can't quite reach the drain pump around the back - think I have to remove the base etc/get the whole thing apart., any next steps ?.. your help is much appreciated. Here's a photo with the labels I refer to ...

 

[Echo the husky]

Is that base full of water?!

 

[spectre]

Is that base full of water?!

err, yes - please read above..

 

[rocks1]

Disconnect the circulation pump. That silver one in the front of pic. It's looks flooded and shorting out the circulation pump

 

[spectre]

Disconnect the circulation pump. That silver one in the front of pic. It's looks flooded and shorting out the circulation pump

..already did that - same problem, plus (as above) pump works fine when powered separately

 

[Echo the husky]

A poke about with an insulation tester should quickly identify the problem.

 

[spectre]

Problem sorted (I think) - I found the drain pump actually towards the front/left, and the impeller accessible from inside the drum - there was a load of crud in there too - pumpkin seeds, etc etc. I cleared out, gave the impeller a turn and it now seems to work fine again (after a reset on the control panel). I can only assume the impeller was stuck and that caused the 30mA mains RCD to trip - does that sound plausible (to any _qualified_ electrical types ?) - either that or said drain pump is on the way out and it could happen again soon..

 

[Echo the husky]

Won't have caused it to trip. The pump should be unharmed even if totally stalled. The RCD only detects earth faults. Most drain pumps are of an all plastic construction with no earth connection and even if very faulty would only blow the plug fuse, unless water was cascading over if of course.

Probably something a bit wet but is now all dry casing the tripping. I would try and get some of that water out of the base if you can to stop it condensing on all the electrical parts, but other than that if it's working you should be good to go!

 

[spectre]

Yep, all good so far - cheers for the help. One other thing I thought of - the harness at the front of the image was partially submerged in the sump water (not over the end terminals of course, just the cable insulation). I've lifted it out of that area now but in in theory could that have lead to earth fault (i.e. if the water soaks into the insulation for long enough etc etc) ?

 

[Echo the husky]

(i.e. if the water soaks into the insulation for long enough etc etc) ?

It's not supposed to soak in but after a long while it often does!