cooker tripping MCB

[Dan Brown]

Hi all
I installed a new beko electric cooker for a friend and it was fine at first the clocks came on etc, and today was the first time they was going to use it, they switched on the hob and it blew the MCB.

I've checked all cable at each point such as Consumer unit, cooker unit and behind cooker.

I connected the L and N to the cooker without the earth and it doesn't trip, so I no its something to do with the earth.

I've done a continuity test by linking live and neutral at the board and testing between these cable at the other end to see if they are touching as I don't have a insualtion resistance tester, and it all seemed ok.

but when I tested between L and E on the on the cable to the cooker there was continuity so I then removed the cable from the cooker and put the tester on the L and E terminals on the cooker and there was continuity.

Does this sound like the brand new cooker is faulty as there shouldn't be continuity between L and E

 

[HandySparks]

I connected the L and N to the cooker without the earth ...

Not entirely 'best practice' in electrical testing.

Yes, it sounds like the cooker is faulty.

As it seems you are an art student (look up 'collage'), best to get in an electrician to check this out.

 

[Deleted member 9648]

[QUOTE="Dan Brown, post: 1234413, member: 78850"


I connected the L and N to the cooker without the earth and it doesn't trip, so I no its something to do with the earth.
[/QUOTE]
May I point out that in view of the likely L-E fault on the cooker your investigation method would have resulted in the entire metal case of the oven being live.

 

[Dan Brown]

Not entirely 'best practice' in electrical testing.

Yes, it sounds like the cooker is faulty.

As it seems you are an art student (look up 'collage'), best to get in an electrician to check this out.

1. I know this is not the best practice and how would you have confirmed it was the earth wire causing the fault?
all I did was disconnect the earth from the cooker and put the breaker on to see if it tripped which it didn't so I turned the breaker back of straight away. when I put the earth back in and tried the breaker it continued to trip.

2. what makes you think I'm an artist. I hate assumptions.

3. I've done level 2 and 3 2365 city and guilds, which yes it does include inspection, testing and fault finding etc. but it's not like doing it in the real world. I've not really had to do any of this on site. and fault finding is not the best of tasks but it has to be done at some point.

4. so no I won't consult a fully qualfied electrician to install 3 cables into the back of cooker. I don't own a multifunction tester to carry out relevant test to confirm faults. So I did what I did am sure it's not breaking the law lol

 

[Dan Brown]

Yes obviously but it was not being touched for the second the breaker was on

 

[Deleted member 9648]

1. I know this is not the best practice and how would you have confirmed it was the earth wire causing the fault?
all I did was disconnect the earth from the cooker and put the breaker on to see if it tripped which it didn't so I turned the breaker back of straight away. when I put the earth back in and tried the breaker it continued to trip.

2. what makes you think I'm an artist. I hate assumptions.

3. I've done level 2 and 3 2365 city and guilds, which yes it does include inspection, testing and fault finding etc. but it's not like doing it in the real world. I've not really had to do any of this on site. and fault finding is not the best of tasks but it has to be done at some point.

4. so no I won't consult a fully qualfied electrician to install 3 cables into the back of cooker. I don't own a multifunction tester to carry out relevant test to confirm faults. So I did what I did am sure it's not breaking the law lol

The thing is it's not the 'earth wire causing the fault'.
Whilst connecting the cooker is not 'breaking the law'....the reason for being able to carry out basic tests is to avoid danger in the event of faults. You should have at least carried out a Zs test at the cooker terminals. Have you considered what would have happened if there was a break in the continuity of the earth due to a bad connection in the isolator or something? As you didn't check this until after the mcb blew the cooker would have worked fine and you could have walked away from a live cooker case and a dead 'friend' soon afterwards.
Worth thinking about mate.

 

[westward10]

Do you actually know the function of the cpc and it's purpose for circuit protection, clearly not or else you wouldn't have disconnected it and probably left the case of the cooker live. Think you might want to leave the electrics in your friends house to competent people.

 

[GMES]

Dan with the greatest of respect, please get someone in that owns the relevant test equipment, under no circumstances should you carry out a bang test to prove something works and is safe for use.
The lads aren't joking when they say you could kill someone doing it that way.
You are not going to find any faults without a tester so my advice would be either invest in a tester or beg and borrow one, as someone who is trained to level 3 you must realise your way is not right and must go against everything you were taught during your studies. Be safe and get some help, all the best with it. As a last thought if you put your location up some kind member may just be local to you and be willing to pop round and help you out.

 

[Octopus]

4. so no I won't consult a fully qualfied electrician to install 3 cables into the back of cooker. I don't own a multifunction tester to carry out relevant test to confirm faults. So I did what I did am sure it's not breaking the law lol

Matey ..... if you want to work as a spark, having a MFT is almost as important as having 2 hands....

 

[telectrix]

Matey ..... if you want to work as a spark, having a MFT is almost as important as having 2 hands....

who needs 2 hands when there's apprentices to be abused?