problems

[tom1]

adding lights in bathroom.

ir 0.06 L/N to E

must be over looking something its not tripping the rcd.

the rcd trips on half current,

only 4 lights on circuit all wired into 1 jb (see pic)

whats my options here , my work is ok the circuit is not

if customer wants me to

replace rcd (does the rcd have to be changed)

find ir fault

if not should i just leave the lights dead and walk,

thanks for the help

 

[Bacon]

Apart from disconnecting the cables with in the J/B and checking to each individual light then you may be able to identify why the circuit tripps.

Whats the flex feeding that looks newish?

P.S Never came across 11 cables in junction box for 4 lights.

 

[tom1]

my mistake 5 lights so thats 1 feed 5 lights 5 switch, my house was the same until i rewired it.

the rcd does not trip with normal use,

it trips on zs test and on rcd test half current

 

[Andy™]

P.S Never came across 11 cables in junction box for 4 lights.

looks like there was almost 13 in there!

 

[Andy™]

i wouldnt want to be adding anything to that death trap unless it gets made safe!

 

[lcdman]

First off I'd ditch the JB and gets some Wagos in there instead, those wire nuts look well overloaded, how many wires per?? What do your L/E & N/E IR tests show?? If it's a (L+N) to E fault then there's likely to be no inbalance to trip the RCD.

 

[Andy™]

If it's a (L+N) to E fault then there's likely to be no inbalance to trip the RCD.

completely forgetting how an RCD works?! he said it trips on half current, so its reasonable to say there is some leakage, which isnt quite enough to trip RCD on its own, but with the half test current it is.

 

[lcdman]

D'oh, point taken Andy. Bloody messy though, don't you think - needs a tidy as well as fault finding.

 

[Andy™]

D'oh, point taken Andy. Bloody messy though, don't you think - needs a tidy as well as fault finding.

definately needs a tidy. and you can guarantee that this isnt the only JB like that in the house!

 

[tom1]

ir is done on L+N to earth as light bulbs will give duf reading,

rcd test 1 is trip in less than 200ms so is this a fail due to posibuility of nusense tripping

what i dont get is why does the rcd not trip now as the ir readings are so low.

L/N to E will still pick up leakage to earth as the cpc lies between the L and N

 

[tom1]

wagose sound like a good idea, i might test a diff light circuit if its ok add them to that.

is it ok to wire lights in this way by this i mean 1 feed to jb then feeds all switch and lights, so if i get wagos would it be ok to wire it the same way or does it all need re routing

 

[Andy™]

ir is done on L+N to earth as light bulbs will give duf reading, rcd test 1 is trip in less than 200ms so is this a fail due to posibuility of nusense tripping

what i dont get is why does the rcd not trip now as the ir readings are so low.

L/N to E will still pick up leakage to earth as the cpc lies between the L and N

the leakage is probably not enough to trip the RCD. and you should be testing RCD in isolation too, so it would most likely not trip at 1/2 and pass. even though im normally the one to say the RCD should not be tested in isolation

 

[tom1]

i agree rcd need to work when under load.

i also found i cable in the cavity filled with polisterene balls it was a sticky mess, isolated it now though

 

[SPECIAL LOCATION]

wagose sound like a good idea, i might test a diff light circuit if its ok add them to that.is it ok to wire lights in this way by this i mean 1 feed to jb then feeds all switch and lights, so if i get wagos would it be ok to wire it the same way or does it all need re routing

Yes ok to go to ONE box or enclosure...

BUT box / enclosure needs to be big enough to contain ALL of the connections..

i.e. you don't terminate CPC's outside of the box...

Section 526 pages 106 & 107 gives guidance for Electrical Connections.

CPC's are susceptible to damage, snap off thus break earth continuity to other accessories.

I would get a suitable sized adaptable box, bang a few 20mm grommet / gland holes the tuck all you wires nicely inside with some Wagos!

 

[Andy™]

i.e. you don't terminate CPC's outside of the box...

Section 526 pages 106 & 107 gives guidance for Electrical Connections.

but you shouldnt make anything worse than when you arrived, so even if all lives are in box and earths outside, its still better than first pic!

 

[tom1]

Yes ok to go to ONE box or enclosure...BUT box / enclosure needs to be big enough to contain ALL of the connections..

i.e. you don't terminate CPC's outside of the box...

Section 526 pages 106 & 107 gives guidance for Electrical Connections.

CPC's are susceptible to damage, snap off thus break earth continuity to other accessories.

I would get a suitable sized adaptable box, bang a few 20mm grommet / gland holes the tuck all you wires nicely inside with some Wagos!

sounds good but thay will have to pay, the bathroom lights will have to go on another circuit untill then.

what about the low ir, could there be something i am mising may be in this jb

what gets me is the cu is quiet new, no lables , no bond to water and they have had other work done recently.

 

[SPECIAL LOCATION]

i agree rcd need to work when under load.i also found i cable in the cavity filled with polisterene balls it was a sticky mess, isolated it now though

RCD's may well need to WORK under load..

But they need to be tested in isolation...

so the circuit doesn't introduce artificially fast operating times!

Page 91 On Site Guide. paragraph 11.1 General Test procedure.

{footnote

there is quite often of the forum the odd bit of barracking about NICEIC making up their own regs & rules....

Yet it very often appears that electricians make up enough of their own rules without any interference from the NICEIC ; \}

Guinness

 

[SPECIAL LOCATION]

sounds good but thay will have to pay, the bathroom lights will have to go on another circuit untill then.what about the low ir, could there be something i am mising may be in this jb

what gets me is the cu is quiet new, no lables , no bond to water and they have had other work done recently.

not done by an "Electrician then!":|

were there any hoof marks outside? ]

 

[tom1]

not done by an "Electrician then!":| were there any hoof marks outside? ]

na they had a new drive but i did find a cowboy hat in the loft.

the stop cock was 2 meters from the oil and that was 1 meter from the cu,

 

[Andy™]

RCD's may well need to WORK under load..But they need to be tested in isolation...

so the circuit doesn't introduce artificially fast operating times!

Page 91 On Site Guide. paragraph 11.1 General Test procedure.

but at the same time, its been proven that connected equipment may stop the RCD from operating at all, which i would say is more dangerous than it operating too fast. maybe a case to test in isolation and not in isolation, and make sure times match?