RCD on bathroom LED mirror.

[tosh-27]

Hi folks,
hope everyone is ok.

We recently had our bathroom done and the electrician fitted and wired in our LED bathroom mirror.
He T'd off the lighting circuit in the loft and added a 5A fused spur as a 'do for now' but said we should buy a 30mA RCD to fit onto the fused spur back box. He said he left it for me to fit but now that i have the RCD won't reset at all.
I've double checked that it's definitely wired the correct way round but kind of thought if it was wired in reverse it would have melted by now.

Any suggestions why the RCD won't reset please.

Many Thanks

tosh

 

[44ALLAN]

"but kind of thought if it was wired in reverse it would have melted by now".

yup.............you've been lucky mate..................

 

[telectrix]

not possible to diagnose fault on tinternet. you need a local electrician. call him back, maybe. then again if he left you to do half the work, maybe not him.

 

[Dohnut]

Your electrician never should have said for you to fit it he is trained you are not. You are lucky you didn't get hurt.

Its seems like you have a fault on one of the circuits that is covered by the RCD, this isn't a fault you can find as you need test equipment. You are best off getting the electrician to come back check the RCD is fitted correctly and get him to trace the fault.

 

[brucelee]

As tel says get another electrican as he obviously wasnt one if he left you to fit the RCD and did he give you a certificate for the works he carried out which isnt worth the paper he wrote it on as he obviously did no testing

 

[Outspoken]

LED = Electronics = back voltage = RCD Trip. I'll bet the LED driver uses the earth as a ground and dumps the unnecessary voltage onto it thus causing an apparent "earth fault" resulting in the inability to reset the RCD. Damn this is so common it hurts!

 

[Rockingit]

LED = Electronics = back voltage = RCD Trip. I'll bet the LED driver uses the earth as a ground and dumps the unnecessary voltage onto it thus causing an apparent "earth fault" resulting in the inability to reset the RCD. Damn this is so common it hurts!

Maybe a whole house worths will (I know it will, have seen it!) but not just one poxy mirror. If you've got +25mA coming from something only 3 or 4 watts to start with, I'd be ripping it off the wall as faulty.

 

[Octopus]

Lets hope you haven't paid him so he has an incentive to come back.

 

[Darkwood]

Ring this so called Electrician up and tell him you have spoke to the local council and they have said that he should have wired the mirror to the 17th bs7671 standards, he should also have issued you with a certificate for the work done and ask him to provide one as the council wish to see a copy, under no circumstances should a competent Electrician be passing on part of the work to his customer if they are not competent themselves.... it could be argued he can to some extent but he would be obliged to return inspect the work and certify it.

The minute he suspects you have contacted other bodies regarding his work i can see him either doing his best to worm his way out of it or rushing back and doing the necessary .... makes me wonder if he actually fitted an RCD himself and couldn't clear the fault so rather than do the right thing he passed the buck to you.

 

[Outspoken]

Maybe a whole house worths will (I know it will, have seen it!) but not just one poxy mirror. If you've got +25mA coming from something only 3 or 4 watts to start with, I'd be ripping it off the wall as faulty.

That depends on the quality of the Tx used to reduce the voltage to that required by the LED. I have encountered some really rubbish ones that dumped the excess voltage from the electronic straight on to the chassis of the electronics, which is connected the EARTH and not the Neutral, thus more than 200V potential was being put onto the earth...that will Trip an RCD instantly..bearing in mind it only has to exceed 50Vac to do this....and if this is a DC sensing Unit then it will trip at very low DC levels too...

 

[Rockingit]

That depends on the quality of the Tx used to reduce the voltage to that required by the LED. I have encountered some really rubbish ones that dumped the excess voltage from the electronic straight on to the chassis of the electronics, which is connected the EARTH and not the Neutral, thus more than 200V potential was being put onto the earth...that will Trip an RCD instantly..bearing in mind it only has to exceed 50Vac to do this....and if this is a DC sensing Unit then it will trip at very low DC levels too...

Like I said - if they're that rubbish I'd be ripping them off the wall!!

 

[telectrix]

simple solution that i discovered. saved me a fortune in razor blades as well. grow a friggin' beard.

 

[KoFi]

good grief ! thats what 6 weeks courses churn out !!

 

[tosh-27]

Really appreciate all of your input folks, many thanks. Certainly has now got me thinking, more about the credentials of the electrician rather than i have an issue with something i did.
I had him recommended to me as well.
Think i'll be calling him and getting him back. Although now i'm worried about what he really does know and is capable of doing.

Many thanks again for all of your input.

 

[Richard]

well, from what you've describved i'm imagining your've only got two cables in the switch?? I can;t see how he would go far wrong TBH! I'm sure theres someone on the forum who's nearby who would be happy to help if your not confident in your current electrician.