help with domestic lighting circuit

[amckay]

i have just fitted a light fixture (from b+q) to my relatives living room ceiling in their council flat. (which has two colour wirings to bs7671)

the light fitting is chrome and has 6 legs coming from the rose leading to the bulbs.

everytime you touch the legs it trips the RCD which you have to wait a good 20 mins before flicking it back on even when there is no demand on the circuit.

i think this is a live to earth fault but not sure

have a look at my link to show you the type of fixture i am talking about, its not the exact one as they have discontinued it but it is very similar

Lights by B&Q Chorley Semi Flush Ceiling LightChrome Effect, 0000005266685

has anyone got any idea what this could be and how to rectify the issue?

 

[i=p/u]

have you earthed it and doesnt need earthed, you could make up a lead and put on a plug and plug in and see if it happens as sockets probably rcd protected, could be fault with the fitting

 

[i=p/u]

just one of them annoying we jobs your saying

 

[trev]

I doubt it is a live to earth fault as it would most likely trip the RCD as soon as the circuit was energised but more information is needed. Is the fitting class 1 or 2? have you earthed the fitting? Is the light on or off when this occurs? Why are you touching the legs of it if it's up on the ceiling (Not really relevant I'm just curious) Is the fitting connected correctly?
Are you an electrician? I admire your willingness to have a go if you're not but would you be so willing to repipe the gas supply to their central heating boiler? Please note I'm not trying to pee on your fireworks here I'm trying to give you good advice

 

[amckay]

I doubt it is a live to earth fault as it would most likely trip the RCD as soon as the circuit was energised but more information is needed. Is the fitting class 1 or 2? have you earthed the fitting? Is the light on or off when this occurs? Why are you touching the legs of it if it's up on the ceiling (Not really relevant I'm just curious) Is the fitting connected correctly?
Are you an electrician? I admire your willingness to have a go if you're not but would you be so willing to repipe the gas supply to their central heating boiler? Please note I'm not trying to pee on your fireworks here I'm trying to give you good advice

not sure if its class 1 or 2, the fitting is earthed, i havnt tried it with the light off only when the light is on. i didnt touch it it was my cousin who touched it (heavens know why) the fitting is connected correctly, no im not an electrician but i am 2330 qualified looking for work in the industry. and no i wouldnt **** about with gas supply!

i might be new to electrical installation, but can you remember all those years back when you were a trainee facing these issues like i am now???

thanks for your advise tho it is much appreciated, and unlike most i do have a bit of sense about me as i am retraining as an electrician after years in the royal air force and not just some kid wanting to earn a fast buck....

 

[tony mc]

I dont understand the bit re

everytime you touch the legs it trips the RCD which you have to wait a good 20 mins before flicking it back on even when there is no demand on the circuit.

If you mean that when you touch the metal fitting it trips the RCD then it is wired incorrectly or faulted as you are the path to earth and the RCD is doing its job by disconecting the supply.

The 20mins bit worries me.

I take it before you started there were no faults present!!

You could remove the fitting and test it when it is disconnected.

IMO I would isolate the circuit and have it looked at by a electrian I know we all have to learn but what if your cousin was injured as a result of this who gets the blame!!

 

[trev]

Just making sure you have a bit of knowledge and aren't a total novice mate. First off it should tell you on the box if it's class 1 or 2. Another giveaway would be did it have an earth terminal. I reckon it's more likely N-e as it's happening when the light is switched on. Drop it down and have a good look (don't forget to turn the juice off first though)

 

[amckay]

thats the bit what worries me, killing someone.

yes, when the metal fitting is touched it trips the RCD.

It seemed fine before the new light was put up tho.

When you said test it, do you mean an insulation and continuity test? or RCD test?

id like to get this sorted asap as it clearly is a hazard but i dont understand because i earthed it from the existing earth cable which was used to earth the previous ceiling rose?

any further ideas pal?

 

[amckay]

what is the difference between class 1 and class 2 by the way?

 

[i=p/u]

if its class 2 it will have a square box within a box and not require an earth, but dont think this is the problem.. back to basics and start from continuity of protective conductors(R1+R2) then on to insualtion resistance , follow what you learnt in 2330 classes remove loads etc and this how you learn, thats if something doesnt stand out at you.... im learning /training at moment too, dont work in the trade full time, but this is where id start....

i would also take light down and put on a lead and see if trips sockets rcd.. then you can say its the light

 

[trev]

Have you got or can you get some testers mate? I know they're really expensive bits of kit and not many trainees have them but I would disconnect it and go through the sequence on the lighting circuit, make the RCD trip and see what happens when you re energise. While the fitting is down check it to see if it's class 1 or 2, that might be irrelevant but it's worth a look. Obviously it's hard to diagnose this from the comfort of my armchair

 

[trev]

As he said, it won'tbe the first time that the sheds have sold a faulty fitting mate

 

[i=p/u]

armchair lcuky git, if you want a back like a question mark..lol

 

[amckay]

trev1 ive just bought a robin continuity/insulation resistance tester off ebay £30 = bargain!
that wont be deliverd for 2 weeks tho.

 

[trev]

Nice one mate, is it calibrated?