Lighting RCD tripping

[68breakbreak]

Hi,
we are in the process of altering our downstairs lighting circuit to incorporate spotlights. 1st fix has been completed, and there are some live wires not connected to any switches.

A fault has recently developed where the circuit keeps tripping out. this seems to have coincided with the plasterers boading over the ceiling. Could it be that the uncompleted 1st fix wiring is causing this problem, or more likely that the plasterers have disturbed something.

Is it worth getting 2nd fix done prematurely to see if this fixes my problem?
thanks

 

[ricicle]

Who did the first fix ?
Why are there some energised, unfinished cables ?
Were the cables ran in such a manner to stop them getting damaged by any further works ?

The installer needs to do an IR test/inspection of the circuit.

 

[68breakbreak]

an electrician did the first fix. some of the original wiring was used to supply the new wiring and it is that wiring which is capped off.
>>were the cables run in such a way to stop them getting damaged by further works? >>>> well i wasn't completely happy with where the cables were going, but I'm not an electrician so trusted his judgement.

 

[Taylortwocities]

Is it the lighting RCD that is tripping, or is it an MCB?

Untitled

• Taylortwocities
• 27 Mar 2010
• 43

 

[68breakbreak]

It's an mcb . There is no test button

 

[Taylortwocities]

Ah, So "Lighting RCD Tripping" is the wrong title then. There is a big difference between and RCD and an MCB.

An MCB will trip when there is a current overload. Does the MCB trip when a particular light switch is operated?

This could be caused by many things. A plasterboard screw through a cable is possible, Maybe a screw in a switch box trapping a wire. You need to take a structured approach and find out when it trips the MCB.

It may just be that you have too many lights for the one 6amp circuit. Have you added up the wattage of all of the lamps to see what the total is?


Oh, and re

Is it worth getting 2nd fix done prematurely to see if this fixes my problem?

This wont help.

 

[68breakbreak]

Thanks for your help.
The mcb is only protecting 1 light in the front room. The other lights in the kitchen which it normally protects are not live. There are however 2 live wires which have been capped off which will eventually feed the the new kitchen lights... So not many circuits at the moment.

It's an intermittent problem. Had the light on all yesterday evening, but today it won't stay on more than 15 minutes.

 

[PrenticeBoyofDerry]

You obviously have a fault on the circuit, the electrics should have never been re-energised without confirming the circuit was suitable to do so. If it was, then in the interim someone has caused/introduced a fault, do you know if the circuit is looped in at light fittings or switch?
I would advise an insulation resistance test is carried out, to help diagnose and track down the fault.

 

[sparkwright]

You say the ceiling has been overboarded.

One nasty way of running cables before a ceiling is overboarded is to notch the old ceiling surface where joists are, and run cables this way. This way means cables are prone to get screwed through when fixing up the new board.

If access above not practical, the correct way is to bash big holes in the ceiling, drill through the joists, run the cables through the joists, and then overboard.

Of course, there are many other factors which be the cause of the fault, so more research is required.

 

[sparkwright]

For god's sake get the fault rectified before they skim/joint fill the ceiling!

 

[securespark]

Wot 'e said!

 

[68breakbreak]

Too late!

 

[Taylortwocities]

Too late for what? The problem needs fixing before any more plaster/decorating is done.

What has been done to localise the fault? IR tests?

 

[68breakbreak]

The ceiling has been skimmed already.. The electrician who installed is coming back on Monday to diagnose and fix. Thanks

 

[Taylortwocities]

Do let us know what the problem is. Thanks