New Plug In Induction Hob Tripping Electrics Occasionally

afromau5 · Nov 13, 2023

Hi all, we had our gas hob removed months ago and finally just got round to putting an induction hob in.

Its a normal 4 ring induction but one of these newer 13amp ones with a moulded plug on.

In the kitchen we have a 45amp cooker switch on the wall which feeds a 2 gang socket in the cupboard underneath. In this we have the oven plugged in (like always) and now the new hob.

Not every time, but a couple of times when turning it on or pan starts heating the house electrics trip off. If i flick back the RCD back on and try again all is ok and works fine. Other times it doesnt trip at all.

Any suggestions on things I can look out for?

Ive attached the consumer unit. Its the far left RCD that trips when it happens

DPG · Nov 13, 2023

With all those circuits you may well be near the trip limit of the RCD. Note this will be well under the nominal 30mA rating of the device.

afromau5 · Nov 13, 2023

DPG said:
With all those circuits you may well be near the trip limit of the RCD. Note this will be well under the nominal 30mA rating of the device.

Thanks. If I was to change the hob for a 'proper' hob thats hardwired to the cooker switch instead of plugged in, would that help at all or is it no different?

If its a good option, given that the cooker has its own circuit can the wiring thats currently feeding the plug socket be used to power the hardwired hob and a single socket for the oven?

timhoward · Nov 14, 2023

afromau5 said:
Thanks. If I was to change the hob for a 'proper' hob thats hardwired to the cooker switch instead of plugged in, would that help at all or is it no different?

In all likelehood, no different.
The RCD on the left is looking for electricity that is going missing in action. If the total missing reached roughly 20-30ma it will trip.
Turning on a large load (e.g. an induction hob) increases the chance of larger amounts of current finding it's way through a neutral-earth fault. The fault could be on any of the protected circuits.

Bottom line, some testing is needed, and unfortunately you'll need a sparks as the test gear required isn't cheap. The good news is that finding out which circuit has the problem is usually quite a quick task.