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I have just had the local engineer out to what started to be an intermittent fault, where the m/c would throw out the main circuit breaker (not just the ring main). This got worse, with the m/c tripping out as soon as it was turned on.
The engineer found some background earth leakage, however this remainend when the following were disconnected: Heater element, Motor, Mains capacitor, Pump and finally the first (black) of the module boards – leading him to assume that none of these were at fault.
Closer inspection of the m/c found a fractured brown sensor wire @ the front of the m/c which was repaired, however the background leakage still appears. An initial test on the pump / spin cycle indicates that the trip stays in. However the leakage did not seem significantly reduced after this repair. Also it would appear that a couple of the LED display elements now burn brighter than the others.
Does anybody have any ideas as to the cause of this, what other investigations I can undertake and whether there might be an economic resolution? The m/c is about 7 years old I think.
Re: Bosch WFP 3300 – Earth trip problem
This doesn’t make sense. If you disconnect the mains suppressor and apply power, the machine is not connected to the mains. If you are still reading leakage, it can only be the mains cable, can’t it?
UKW does not support or condone live testing, please don’t do it.
Penguin45.
Re: Bosch WFP 3300 – Earth trip problem
Penguin45 wrote:This doesn’t make sense. If you disconnect the mains suppressor and apply power, the machine is not connected to the mains. If you are still reading leakage, it can only be the mains cable, can’t it?
I read this differently and assumed the machine is being tested for earth leakage with a meter and possibly from inside the cabinet rather than the plug end!
A couple of possibilities to consider:
- 1. Are there any signs of water leaking or is the machine situated in a damp area?
2. Are any of the wires chaffed and touching the cabinet or any other ‘earthed’ part of the machine?
Remember though, as Penguin so rightly says:
UKW does not support or condone live testing, please don’t do it.
Twoten you’re absolutely right; of course it wasn’t plugged in. The plug was removed and a multimeter tested across the earth terminal and the live / neutral pins, since the m/c is leaking to earth.
Your conclusions are exactly what the Engineer & I came up with. With regard to damp however, the m/c has been in the same place for 5 years now and never misbehaved even during damp winters.
Therefore maybe there is a residual “normal” background leakage – probably due to some damp – and the broken sensor wire was all that was required to push the leakage over the circuit breaker’s threshold (although it did not appear to be touching the cabinet). It was run after this sensor wire was mended for a short cycle last night without incident .
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