Appliance isolated - RCD still tripping

[rlwalshy]

Hi all - hope you can give some advise experience.

Last week our saniflow went kapput and tripped out our RCD. Eventually I identified the issue and pulled out the fuse section from the fused spur and then the RCD reset fine.

The problem know is that every once a while (twice per day) the RCD trips. Unusually it's mainly been in the middle of the night or when we're not in (the freezer defrosted whilst on holiday )

I've got a man coming to replace the saniflow next week. I assume it must be related? How come this is happening with the fuse popped out?

 

[Adam_151]

The saniflow is probably still presenting a neutral to earth fault, which causes the RCD to trip only when sufficent current flows through it. which is dependant on overall loading of the system, as well as to an extent the positioning of those loads (when on the same ring circuit as the fault)

To provent it happening, assuming the spur is unswitched, then you should disconnect the outgoing flex from it fully until the device can be repaired

 

[EFLImpudence]

Last week our saniflow went kapput and tripped out our RCD. Eventually I identified the issue and pulled out the fuse section from the fused spur and then the RCD reset fine.

In view of what you say below could this have been a coincidence?

How come this is happening with the fuse popped out?

This is because the Neutral and Earth are not disconnected. Any leakage between these two wires will trip the RCD.

The fault could be water leaking on to the wiring in the saniflow or it could be elsewhere. If the problem is not cured with a new saniflow you will need the circuit tested with the appropriate equipment.

 

[rlwalshy]

Thanks for the replies .. you may have guessed I'm a bit of a novice.

Assuming the issue is with the earth wire would there be any benefit in switching off the relevant circuit on the fusebox as a temporary measure?

Would this stop these 'randam' RCD trips?

Thanks in advance.

 

[holmslaw]

..

 

[PrenticeBoyofDerry]

As holmslaw has stated in above post, the fault is between neutral and earth and even opening the protective device will not remove this connection.
You need to identify the neutral and earth for this circuit at the consumer unit and disconnect them from there termination points on the busbars.
After disconnection it would be advisable to tape the ends of the conductors up for the moment, to prevent contact elsewhere.
This will stop the neutral-earth fault being detected by the RCD.
Remember the safe isolation prior to work being carried out.
Or depending where the fault lies, you could disconnect the neutral and earths at the FCU. If the fault lies upstream to the FCU that should sort the tripping out. Again Isolate circuit.