Cooker tripped electrics - Not sure why?

[jackpot]

Cooking tea about an hour ago and suddenly the electrics had tripped (The RCD circuit switch on consumer unit).
At forst thought this might be the boiler as we have been having trouble swith it but upon isolating the hob switch the RCD switch worked fine. If i turned the hob switch on the RCD switch would trip again.

Any ideas?

Had a look inside the socket that is the problem and again if this is switched on the RCD switch trips but the inside of the socket seems in good condition and everything is connected ok. Had a look in the consumer unit and the hob swictch also seems to be ok with a thin brown cable coming out of it and thats connected fine.

Any clues on whats causing this, never had a problem before. Apart from wasting some chicken im starving!!!

 

[Lectrician]

Sounds like one of your elements in the cooker has failed or is failing.

What is the rating of the main RCD?

 

[jackpot]

What you mean rating? Sorry bit thick.

On the switch it say RD236/030 and 63A If that helps.

House had a full rewire last May so everything should be in order.

 

[Lectrician]

A 30mA main RCD is not compliant, and yours certainly sounds like it.

The 17th edition of the regulations requires that a dual split load unit be fitted.

Can you find out your earthing arrangements?

Link

 

[oharaf]

The 17th edition of the regulations requires that a dual split load unit be fitted.


Link

Not strictly true Lec!!! But just being finickity!!!

Completely agree a Main RCD Isolator is not to regs. I am wondering if it is a split load board and it is the RCD tripping there.

Who re-wired the house? Do you have a certificate?

Post a pic of the consumer unit and surrounding area

 

[jackpot]

Will try and work this one out. I have a earth cable about 8mm thick coming out the consumer unit and connected to gas pipe work etc inside the meter cupboard. For lights etc the earth is all in the same sleeth as the neutral and live.

Just to clarify which is the main RCD. The switch that trips or something else. There is also a grey rectangular box with a red on/off swich made by wylex connected to the consumer unit by 2 thick grey cables. Could this be it? This states 240v 100A on it.

 

[jackpot]

The 17th edition of the regulations requires that a dual split load unit be fitted.


Link

Not strictly true Lec!!! But just being finickity!!!

Completely agree a Main RCD Isolator is not to regs. I am wondering if it is a split load board and it is the RCD tripping there.

Who re-wired the house? Do you have a certificate?

Post a pic of the consumer unit and surrounding area

Yes i have a full certificate and warranty etc Im off to work in a bit so cant get pic up until tomorrow.

 

[ericmark]

Cookers in general use mineral insulated elements to do the heating. Even in A1 condition when new because the mineral is hydroscopic (it will absorb moisture from air) they can get earth leakage and once this exceeds the limit of any RCD it will trip.

Also the element can become faulty with will also cause the RCD to trip.

Until 2008 it was normal not to feed the supply for a cooker through the RCD but it has been in my house since 1992 with no problems.

In 2008 any cable buried in a wall at less than 50mm unless one of the special exempt types needed RCD protection. In theory Ali-tube cable could be used without RCD protection but in practice it is very rare.

As a results where water is absorbed it can trip the RCD when there is no fault.

However to work out if there is a real fault or just a little dampness one needs expensive meters and although one can dry out the elements it is normally a dangerous process and I am not prepared to say how it's done on here. It is not a DIY job.

So sorry only real way is to get an electrician to check it out.

Chances are if it was not used for a long time and when you then tried it fault appears then likely it can be cured without using any parts. If it was in regular use and it goes wrong then likely faulty and will need some new parts fitting.

 

[jackpot]

Thanks

Could the problem be diagnosed better if the hob was disconnected from the RCD and connected to a non protection. Turn the hob on and see if the rings heat up. If not then a probable heating element has gone. Wont try this myself but want to get a better understanding of it.

 

[jackpot]

This is the same CU thats in the house.

http://www.electricalwholesaler.org.uk/shopping/pgm-more_information.php?id=404&=SID

 

[Taylortwocities]

Yes, but there are many ways to configure it. We need a pic of your actual board. Ta

 

[plugwash]

The 17th edition of the regulations requires that a dual split load unit be fitted.

Really?

My understanding is the regs talk about minimising inconvinance but don't say anything about how far you should go in acheiving that. Dual RCD split boards are marginally better than boards with a single main RCD and are tollerated by the likes of the NICEIC but they are still a long way from complying with a strict interpretation of the regs.

 

[securespark]

the mineral is hydroscopic (it will absorb moisture from air)

Don't want to sound pedantic, but it's hygroscopic.

 

[ericmark]

Thanks

Could the problem be diagnosed better if the hob was disconnected from the RCD and connected to a non protection. Turn the hob on and see if the rings heat up. If not then a probable heating element has gone. Wont try this myself but want to get a better understanding of it.

I think you may have worked out the cure. If you have then I expect you will realise why I have not spelt it out as it is dangerous.

And "securespark" yes I had miss-spelt hygroscopic and it does matter of course is anyone does internet hunt.