Hang on a sec you said something i want to clarify, how many RED/BLACK cables do you have at the light, two red and two black or one of each?
Lights, Camera - No Action
- Thread starter Zarian2013
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16 A RCBO is rather large for a lighting circuit
Did you have to pull on the cable to get some spare to strip back
Are the landing lights controlled by a one gang or three gang switch?
An insulation Resistance test would be useful, but obviously you need that equipment !
Any pictures
Did you have to pull on the cable to get some spare to strip back
Are the landing lights controlled by a one gang or three gang switch?
An insulation Resistance test would be useful, but obviously you need that equipment !
Any pictures
Whilst I agree a permanent LN short would always trip the circuit my only conclusion ( which is why I hoped a more experienced Sparks could help) is that possibly the movement on the cable has somehow broken down the core insulation so that the when current flows ( loaded) there is an arc possibility.
Rare as it seems I can't come up with any other scenario...
Wish someone would though, I do not fancy knocking my walls around to rewire....
Rare as it seems I can't come up with any other scenario...
Wish someone would though, I do not fancy knocking my walls around to rewire....
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I have read with interest what has been said and it would seem you have made no errors so there is only one likely reason for this fault.
Neutral earth short circuit.
Where no current is being drawn then the voltage neutral to earth will be the same so no current will flow so the RCB part of the device will not be triggered.
As current is drawn the voltage of the neutral will rise towards that of the line so now any connection between neutral and earth will cause current to flow and the RCD to trip.
Step one must be to turn off isolator (Not the MCB) has to be the double pole device which will turn off both line and neutral.
Now measure between neutral and earth should be better than 1kohms. I will guess it's not 1kohms and you then have to likely at the consumer unit to start with work out which neutral is down to earth and slowly by hopping from one ceiling rose to next isolate where the two are joined and correct.
There is no quick fix it is a laborious process of elimination until the fault is found. It does not even have to be on lights although likely it is.
As a second likely unrelated comment in the main ceiling roses are rated at 5/6A and they work as both fixing medium and junction box. So in the main lighting circuits are limited to 5/6 amps so it would seem to have a 16A RCBO some one has been playing who did not know what they were doing so I would be looking where clearly some work has been done.
Neutral earth short circuit.
Where no current is being drawn then the voltage neutral to earth will be the same so no current will flow so the RCB part of the device will not be triggered.
As current is drawn the voltage of the neutral will rise towards that of the line so now any connection between neutral and earth will cause current to flow and the RCD to trip.
Step one must be to turn off isolator (Not the MCB) has to be the double pole device which will turn off both line and neutral.
Now measure between neutral and earth should be better than 1kohms. I will guess it's not 1kohms and you then have to likely at the consumer unit to start with work out which neutral is down to earth and slowly by hopping from one ceiling rose to next isolate where the two are joined and correct.
There is no quick fix it is a laborious process of elimination until the fault is found. It does not even have to be on lights although likely it is.
As a second likely unrelated comment in the main ceiling roses are rated at 5/6A and they work as both fixing medium and junction box. So in the main lighting circuits are limited to 5/6 amps so it would seem to have a 16A RCBO some one has been playing who did not know what they were doing so I would be looking where clearly some work has been done.
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Thanks for that.
All because I changed the lampholder from Edison to GU10. Worked OK up until then, but the previous Edison holder was cheapy and the bulb base welded itself to it, and I prefer the GU Halogen light anyway.
All because I changed the lampholder from Edison to GU10. Worked OK up until then, but the previous Edison holder was cheapy and the bulb base welded itself to it, and I prefer the GU Halogen light anyway.
I think eric is meaning 1MΩ (one million ohms) as the minimum recommended value for a cable - although not good.
Less than 15kΩ could cause the RCD to trip - <8kΩ definitely should.
Less than 15kΩ could cause the RCD to trip - <8kΩ definitely should.
ONE RED, ONE BLACK
Have you disturbed any other wiring in the property, such as loosening off the light switch front, or drilling holes anywhere?
1 Gang, These are not hall/stairs/landing - 2 way switching , just 3 lamps on the landing wall to illuminate said area only.
Yes I did have to ease the cable to facilitate the redressing.
there was some spare between the previous holder and wall ( where it emerges) but as stated at the outset the immediate inch or two was hard and brittle so had to cut back to find pliant outer and inner sheathing,
I presume this is PVC PVC cable, It does not have a black outer sheath.
RCBO will pick up both earth fault and short circuit fault, which one you are having hard to know.
Since it all worked fine before being disturbed,
Plus the fact that the other lights work suggests its something to do with when moving the cable a joint has been pulled. But if this was slack cable in the back of the fitting I doubt it. Did you pull any cable out of the wall.
Its all guess work though.
I would want to verify though that I did not have a bad batch of lamps, and try a lamp that you know works. Sounds like you have done this though.
Needs fusing down to a 6 or 10 amp RCBO as well I would suggest.
RCBO will pick up both earth fault and short circuit fault, which one you are having hard to know.
Since it all worked fine before being disturbed,
Plus the fact that the other lights work suggests its something to do with when moving the cable a joint has been pulled. But if this was slack cable in the back of the fitting I doubt it. Did you pull any cable out of the wall.
Its all guess work though.
I would want to verify though that I did not have a bad batch of lamps, and try a lamp that you know works. Sounds like you have done this though.
Needs fusing down to a 6 or 10 amp RCBO as well I would suggest.
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