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[hobbis]

Hi, can you help. We have an electric Lofra cooker that when you use the oven or grill it trips the RCD. The other electrical appliances do not trip the RCD.

The RCD is a Tenby R8030 type. 30mA sensitivity.

[kbrownie]

hobbis
Has this just started, is it a new problem, has it worked ok in the past.
Check all terminals are tight and correctly installed and check for moisture/damp in and around cables.
KB

[hobbis]

Hi, Thanks for taking the trouble to reply. It is a new cooker which we have been the top hotplates only. It was the first time we tried to use the grill it tripped the RCD and then we tested the oven and the same thing happened. We did have all our electrics rewired and a new box done by what we lwter learned was a doggy electrician. I am now nervous to ask another electricain until I have some confidence on what might be causing the problem. It will have to be looked at by an electrician but how will I know he isn't trying to rip me off, women do get ripped off so I need to have some facts if poss.
Thanks

[kbrownie]

hobbis,
RCDs main function is trip when an above permtted value of earth leakage is measured. i.e. your likely to have 30ma RCD so if a value of around 30milli-amps of earth leakage is detected on the circuits protected by this RCD it will trip( the true tripping value is about 25ma)
So where assuming it only trips when cooker is being used, have you tried using it with nothing else on in the house? does it still trip?
earth leakage is when the the currents passing through the line/live do not equal the return current in the neutral, this normally lost via earth through the circuits, it is not unusual to have a small amount as most equipment does have some, PC and Refrigerators are amongst the highest.
So it may not be your circuit that is faulty but your cooker, it may be worth returning it and exchanging for a new one.
The cooker is best put on circuit on it's own especailly if it has a large power output.
KB
PS.
If you feel the need to call an electrician, try find one that is part of one of these schemes Google "competentperson.co.uk"
Have three round for a look and you will get a good idea of price.
KB

[bd3cc]

Have experienced brand new cookers tripping an RCD, so many were connected on to the "non RCD" side of a split load board for this reason.
As yours is not a new build, and does not come under 17th edition regs, I would try to move it to the non RCD side of the CU.
I doubt that the circuit is faulty, as a cooker circuit is a single cable, but do, as suggested ,check the tightness of the connections.
A suggestion only, but am ready to be shot down.