Faulty cooker of faulty consumer unit? please help

POPART_3

I bought a new kitchen inclusive of oven and hob (homark 02-700401) over a year ago and stored it a spare room until I was able to fit it.

I finally got round to putting it in a couple of months ago and tried it out, albeit very briefly and all seemed ok. Since then I have had a new Protek Supra range ip40 RCD consumer unit installed and on trying the oven thereafter the RCD tripped after about 1 minute either when on oven or grill. On resetting and trying again it came on for maybe 40 seconds and then tripped again and the cycle continued. The electrician who fitted the consumer unit told me that it would be the appliance that was at fault and to seek appliance advice.

On looking around the web i found an article which indicated that the elements may be damp and that if one were to persevere and get some heat through, on drying out the problem may be solved. I kept on trying to no avail, then unwired the cooker from the mains and connected it instead to a normal extension lead and plugged the cooker on via a socket on another circuit. With perseverence the cooker and the oven both eventually came on and stayed on for 20 mins or so until switched off. I then connected the cooker back to its original circuit on the cooker rcd and found myself back at square one....tripping immediately. I disconnected it again and put it back on the extension lead, plugged it in a normal wall socket again, which worked fine before and this time it just started tripping again.

A mate of mine took the cooker to his house (non RCD) and it blew his fuse immediately. Up until this point I felt sure the fault must have been with the consumer unit as opposed to the cooker itself. I really would appreciate any advice that any one can offer.

I rang a few appliance repairers and most say the elements have gone, but if this were the case then why did it work so well for the period I had it on?

muckybutt

Sounds like elements but it could be the wiring on the appliance itself that has now gawn tits up.

If its now blowing fuses / mcbs then the fault has cnanged from a neutral earth fault to either a short between live and earth or live and neutral, either way you need a qualified appliance engineer to look at it and diagnose the fault and give an estimate of the repair.

Can I just ask why a ip40 unit installed ? and why Protek ???? they are renound as being garbage !

Owain_Moneysaver

The electrician should be able to test both the RCD for sensitivity, and the cooker and its circuit for insulation.

Maybe he doesn't know how.

luap2411

Sounds like you are having some fun !

Firstly elements quite commonly fail on cookers, even when new, it is quite likely that this is the fault. Many elements are made down to a price in China now and certainly don't last as long as they used to.

Personally I don't buy the drying out theory, generally if they are leaky then they will always have a weakness and fail early. It's easy for an electrician to test the insulation of the elements in a cooker, they are quick to replace, and mostly under £20.

The fault is an earth fault which should trip the rcd. New consumer units mostly have two rcds, so maybe your cooker and socket ring are on two different rcds. Although in fairness they should both operate so quickly that without test equipment you should not be able to notice any difference in speed of operation.

You friends non rcd consumer unit would still operate on a reasonable earth fault, the mcb would just take a little longer than an RCD.

Earth faults can be pretty sneaky. Often they get progressively worse, which may account for some of your differences in device operation, temperature and moisture can also affect suspect rcds. If this one can generate enough grunt to take an mcb out quickly I would forget any attempts to dry things out.

Going back to basics, the rcd is there to protect you and your family, if you have ANY doubts about it get it tested by a qualified electrician. He/she will have a meter to test the speed and sensitivity of operation of your rcd(s), and he/she will also have another meter to measure the insulation resistance of your cooker elements, or whatever is going to earth. Well worth spending the money for your safety, and also sanity, last thing you want is the cooker switching off halfway through Sunday lunch !

BTW - The last poster is right Proteus are not considered one of the better makes. If your CU has been installed in the last two years it should have two rcds, or rcbos fitted, and the electrician should have given you quite a bit of paperwork. The cooker issues is separate, but be suspicious if you didn't get any of the above.