Neff B15M52N3GB/01 electric oven tripping RCD intermittently

[Racash01]

The RCD trips when using my Neff electric oven every now and then sometimes it doesn’t trip at all, and it is not function dependent, I have checked the blub holder, function switch thermostat all three elements and everything seems fine the resistance readings I have are as follows: Bottom element 41.7 ohms, Motor element 25.3 ohms, Top grill element 40.6/35.1 ohms (dule power) and Oven fan motor resistance reading is 95.2 ohms. The only thing I can think off is the oven motor has this is on the high side (be it slightly). I’m I right in thinking it could be the motor or is the reading of 95.2 on the oven motor, ok? Any help with this will be much appreciated. Thank you.

[tubafan]

The RCD is tripped by leakage to earth and you don’t appear to have tried to measure that. Unfortunately a normal multimeter isn’t ideal for taking that measurement but is still worth a go. Otherwise you’ll need to isolate each part in turn to find which one is causing the trips.

[electrofix]

the resistance readings you have are ok and as tubafan is saying its an earth fault you have

the intermittant part of this makes it difficult to find as it can be an earth fault on one of the elements or a bad joint sparking causing the trip to go

you also have to understand the trip in most houses measure multiple circuits and it adds up. The trip goes when it get to 30 so if you cooker is 25 it wont trip till you turn something else on with a reading of 6 and it goes

Dave

[Racash01]

Thank you for helping me out here,

I realise that this is not going to be an easy fault to find, the only reason I thought it might be the oven fan is due to a surge that this might create, but as the fault is intermittent, I think I should wait until the fault gets worse (as this might make it easier to fault find).

The other option I have is to get the cooker wiring checked out by an electrician, the rating and MCB type is a Crabtree is B40 61/b40 and the RCCB is on a split load and the one that trips is a Crabtree B40/30mA 61/B14030. I’m I right in thinking that these are of a standard rating for a cooker circuit?

I am just trying to rule out any nuisance RCCB/RCD tripping. Of course, I will get a qualified electrician to check the cooker circuit out properly if this is what is required.

Racash.

[electrofix]

if its tripping a 40 a breaker and not the RCD thats a whole different ball game

it might just be the breaker or connections to have a problem

what you have to realise is to blow a breaker the current has to be higher than its rated current. that means pulling over 40A ( 10 KW)

unless there are other things on the circuit that’s hard

turn off the breaker and see if anything else goes off

Dave

[tubafan]

That Crabtree device is an RCBO so I think this is still much more likely to be an earth fault issue than an overload one. As electrofix has said pulling over 40A on a cooker circuit takes some doing.

[Racash01]

I’m sorry I think I caused some confusion by mentioning both the RCCB and the MCB on my pervious reply.

The electric cooker is the only appliance connected on the B40 61/B14030 RCCB circuit which is the one that is intermittingly tripping.

I’m I right in thinking that as the B40 RCCB acts like both a MCB and a RCD the electric oven is wired correctly in line with the B40 RCCB and a cooker isolation switch?

Racash

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