30mA RCD Tripping, New Induction Hob

[nitro23456]

Ok, update.

I left everything on last night apart from cooker circuit MCB.

Put it on this morning and RCD tripped.

Went round turning things off at sockets/switches and now all MCB's are on and everything ok.

Currently the kettle, washing machine, landing light and outside lights are all switched off or unplugged and I can use the hob and bathroom lights.

Must be one of these. I'll attempt to track down which one when I get back from work. Im hoping outside lights.

 

[ericmark]

As to cause, likely some thing with an earth connection, as to cure, if the consumer unit will take RCBO's then that is the way to go. Not a DIY job really.

314.1 Every installation shall be divided into circuits, as necessary, to:
(i) avoid hazards and minimize inconvenience in the event of a fault
(ii) facilitate safe inspection, testing and maintenance (see also Section 537)
(iii) take account of danger that may arise from the failure of a single circuit such as a lighting circuit
(iv) reduce the possibility of unwanted tripping of RCDs due to excessive protective conductor currents produced by equipment in normal operation
(v) mitigate the effects of electromagnetic interferences (EMI)
(vi) prevent the indirect energizing of a circuit intended to be isolated.

In the main it is considered two circuits are enough to "(iii) take account of danger that may arise from the failure of a single circuit such as a lighting circuit" however that depends on the house, with a caravan we have everything on one RCD however we also have battery powered lights, you may fix it now, but likely it will return, being able to run items from a ring final on a different RCD it the main way to find what is causing the RCD to trip.

A quick cure is to use an insulation tester on the neutral to earth connections for each circuit, and find what circuit is really at fault. However there are some things you can do, unplug anything not in use which has an earth connection.

The one which is often used as an example is a bit of damp toast or bread stuck in the toaster, this is the real fault, but the fault is an earth neutral fault, so with no power being used it does not trip the RCD, however plug in the kettle and pop the RCD trips, making one think it is kettle at fault.

 

[nitro23456]

I have a plug in RCD which I use for outside stuff like pressure washer for the car.

Would that be any use to help narrow it down? I.e plug the kettle in using it and rule that out.

Half the problem im having is im at work in day light hours so having to do everything in the dark when the RCD cuts everything.

 

[EFLImpudence]

I have a plug in RCD which I use for outside stuff like pressure washer for the car.
Would that be any use to help narrow it down? I.e plug the kettle in using it and rule that out.

Probably not.

If it were a 10mA one it may find a faulty appliance but you won't be able to connect it to the hob or (without a lot of bother) the lights.
If it is 30mA like the main one then it is extemely unlikely to help.

Half the problem im having is im at work in day light hours so having to do everything in the dark when the RCD cuts everything.

As you said, then - "Time for a professional i think."

As to what tools are required -
An earth-leakage clamp meter and an RCD tester.

 

[nitro23456]

Narrowed it down to the washing machine.

That's the wifes Christmas present sorted as well then.

 

[ericmark]

Narrowed it down to the washing machine.

That's the wifes Christmas present sorted as well then.

Don't forget the PPE required when she throws stuff at you. Mine would go crazy if I bought her a new kitchen appliance for a Christmas present. I would need a hard hat and be in spare bedroom for the year.