Oven trip new replacement RCB when being switched off.

[BorisJ]

Oh dear!

We had better start informing various manufactures they have been building their RCD's wrong!
View attachment 13445 View attachment 13446 etc.. etc...

I dear. I meant MCB.

 

[sirsparkabit]

I dear. I meant MCB.

Multiconfusual. Complete. Bozo

 

[runningpiglet]

I'm having my house re-wired and have an RCB trip issue with the oven. The oven works fine and does not trip while in use, and never tripped the previous RCB, which has now been replaced.

It's a Bosch oven controlled by a rotary switch. When you are turning the oven off, turn the switch anti-clockwise, (Straight from "oven" to "off") the new RCB trips. If you rotate the switch clockwise, through all the other settings (grill, fan, etc.) to the off position, the RCB does not trip.

The electrician says this is a fault with the oven. I have told then the oven never trip the previous RCB when being switched off, but they still say its an oven fault.

So the question is - Is this an oven fault that was previously undetected by the older RCB, or is it related to the new RCB or the new wires to the oven?

TIA

The electrician and you are both right! The oven switch is sparking on switch off, this doesn’t often actually cause leakage to earth so strictly speaking an RCD shouldn’t trip however many modern
RCDs do because they are sensitive to the spark’s radio interference. The ideal solution would be to fix or replace the switch, fitting an RC snubber device across the switch to suppress the spark is another option, worst option would be to try loads of alternative RCDs until you find one that doesn’t trip on the spark (while still responding correctly to 30mA imbalances).