tegwin
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| posted on 2/12/09 at 06:45 PM |
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HELP!! House Electrical Issues
I have a nightmare problem, can anyone help?
Whilst everyone was asleep this morning all of the power went off...
The main trip just after the meter (I assume some sort of RCD) had tripped....
After process of elimination I can prove that the lighting circuit (only one lighting for the entire house), is causing the problem.
If I pull the lighting fuse out of the box, the power to the rest of the house works perfectly without tripping the RCD.
The weird thing is, I can put the lighting fuse back in and switch on the house RCD, everything comes back on including the lights, for about 6-10
mins, and then pop the main RCD trip thing goes off again...
I have run around the entire house in that 6-10 mins turning on every single light one at a time to see if one of the lighting systems has a fault on
it... but all of the lights seem to work...
So why is the lighting circuit tripping the RCD and not blowing the fuse? (5A)
Any suggestions of what to try next? I could admit defeat and call in some help, but I would rather not have to!
The house is 1900ish, appears to have been wired badly, some rubber, some plastic, cables with odd colours... I fear a massive short somewhere under
the floors.... we had new carpets fitted last month
[Edited on 2/12/09 by tegwin]
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Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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turbodisplay
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| posted on 2/12/09 at 06:55 PM |
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At a stab in the dark, could water be in the electrical circuit, as it has rained alot recently. An Rcd is designed to trip when current leaks to
ground. The current flowing could just be below what is required to trip, then randomly increase above limit, then trip RCD.
Do you have dimmers, a fault could cause it to trip, if it is leaking to ground.
Check each switch for water (ideally with no power), looking for water flowing down the wires.
Next look at the light pendants for water.
Darren
[Edited on 2/12/09 by turbodisplay]
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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andyharding
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| posted on 2/12/09 at 06:55 PM |
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A short between live and earth is most likely causing your problem. This won't be bare wires touching but more likely water in a light fitting,
a trapped cable in the back of a switch or just really old cable that is starting to break down.
Are you a Mac user or a retard?
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coozer
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| posted on 2/12/09 at 06:57 PM |
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Earth leakage is what trips the RCD... there would appear to be an intermittent fault somewhere in the circuit.
You'll need to get a leccy in with a megatester to trace which area has the fault (got any mice? They like lunching on the insulation )
1972 V8 Jago
1980 Z750
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Russell
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| posted on 2/12/09 at 07:05 PM |
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Ironic signature in your posts there!
I'm a bilingual illiterate. I can't read in two languages.
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Rosco
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| posted on 2/12/09 at 07:13 PM |
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It's a bit odd for an intermitant fault to behave predictably.
Do you have any lights on timers or outside lights on PIRs. i.e. anything that swtiches automatically.
EL trips are generally set with a very low threshold and a very small or no delay - designed for personnel protection. Water is probable given recent
weather, but if the interval from switch on to trip is repeatable at 6 - 10mins then you should for something that changes in that time, something
that heats up or expands perhaps, something on a timer, central heating timer.....?
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big-vee-twin
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| posted on 2/12/09 at 07:16 PM |
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An RCD detects low level currents to earth 30 milliamperes to be exact.
All electrical equipment has some leakage to earth especially computers and cooker elements also transformers.
Do you have any low voltage downlights in the house a leaky transformer could be the culprit.
Sometimes it takes a wound component a few mins to warm up and start sweating before any trips go.
If it was a fault in the cabling (short) the circuit wouldn't be ok for a few minutes, I think it would go straight away.
Could also be extractor fan connected to lighting
Duratec Engine is fitted, MS2 Extra V3 is assembled and tested, engine running, car now built. IVA passed 26/02/2016
http://www.triangleltd.com
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daniel mason
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| posted on 2/12/09 at 07:20 PM |
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u2u me mate and will try to help. live to earth fault would trip an mcb so i would imagine you either have a faulty appliance plugged in somewhere
causing slight leakage then something else taking it over the rated m/a. or water in a fitting,(usually an outside light)
another problem we have been having lately at work is with earth faults on boilers, usually in pcb
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MikeRJ
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| posted on 2/12/09 at 07:22 PM |
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Do you have a porch with a light? Quite common for them to cause this kind of problem.
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Bigheppy
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| posted on 2/12/09 at 07:45 PM |
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You had a carpet fitted last month, perhaps they hit a cable. It has been known that the fitters secure loose floorboards before fitting the carpets,
a nail could have pierced the outer sheathing and causing a short. I used to get called out often to gas leaks. Worth a check 
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NeilP
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| posted on 2/12/09 at 08:01 PM |
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Turn off all the lights and reset - If it stays on beyond 10 min then you likely have old wiring thats moving under the slight heat of the load and
then shorting - any other immediate fault (e.g. nail, water) should trip out immediately...
Only other thought is you might have a dodgy flourescent bulb somewhere that's putting an equally dodgy spike on the system after it warms
up?
You'll have to rewire at some point - If you ever want to sell your house then you need a certficate of testing now from an NICEIC registered
electrician 
If you pay peanuts...
Mentale, yar? Yar, mentale!
Drive it like you stole it!
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Liam
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| posted on 2/12/09 at 08:16 PM |
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quote:
Originally posted by NeilPYou'll have to rewire at some point - If you ever want to sell your house then you need a certficate of
testing now from an NICEIC registered electrician
Eh? Says who? For one, I think the other approved schemes (NAPIT et al) would have a thing or two to say about that (if it were true).
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NeilP
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| posted on 2/12/09 at 09:34 PM |
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Liam,
Your right - I checked - not complusory but under the optional bit of the Homebuyers Information Pack the survey would include a by inspection check
of electrics.
"General advice
Safety warning: Periodic inspection and testing of electrical installations is important to protect your home
from damage and to ensure the safety of the occupants. Guidance published by the Institute of Electrical
Engineers recommends that inspections and testing are undertaken at least every 10 years and on change
of occupancy. All electrical installation work undertaken after 1st January 2005 should be identified by an
Electrical Installation Certificate."
We moved just when this beastie was being agreed on and I could have sworn at the time they were going to make both electricity and gas safety
inpections compulsory - maybe that was just for rented property...
If you pay peanuts...
Mentale, yar? Yar, mentale!
Drive it like you stole it!
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tegwin
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| posted on 2/12/09 at 10:14 PM |
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quote:
Originally posted by NeilP
Liam,
Your right - I checked - not complusory but under the optional bit of the Homebuyers Information Pack the survey would include a by inspection check
of electrics.
"General advice
Safety warning: Periodic inspection and testing of electrical installations is important to protect your home
from damage and to ensure the safety of the occupants. Guidance published by the Institute of Electrical
Engineers recommends that inspections and testing are undertaken at least every 10 years and on change
of occupancy. All electrical installation work undertaken after 1st January 2005 should be identified by an
Electrical Installation Certificate."
We moved just when this beastie was being agreed on and I could have sworn at the time they were going to make both electricity and gas safety
inpections compulsory - maybe that was just for rented property...
Dont start talking about that bollocks... it makes me angry....
The last Part P qualified electrician I had blew a hole in my consumer unit... so I fired him and fixed the fault myself... I mean, seriously what
kind of muppet wires an industrial compressor backwards....
Chears for the replies all!
I have gone round and switched off every single light, so nothing is on.... and it still trips after a few mins of working... which is a bit odd...
How would a "qualified" electrician figure out where the short might be?
I just dont get how it can work fine, and then in the dead of the night when nothing is switched on... simply stop working...
Even if all of the lights are switched off... could a duff bulb cause the issue? Most of them are those evil energy saving jobbies...
[Edited on 2/12/09 by tegwin]
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Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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JoelP
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| posted on 2/12/09 at 10:27 PM |
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a spark would firstly disconnect the light circuit from the board and test the insulation. He could then seperate individual runs and test lengths
seperately, to see if its a general old cable problem or something specific.
If it trips with the lights all turned off it would suggest a neutral to earth fault somewhere, but i would agree that the long consistant delay does
sound like something specific.
In the short term you could remove the lights off the RCD, but id hesitate to suggest that without also saying you need it testing and fixing
properly.
Beware! Bourettes is binfectious.
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JoelP
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| posted on 2/12/09 at 10:27 PM |
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quote:
Originally posted by tegwin
Even if all of the lights are switched off... could a duff bulb cause the issue? Most of them are those evil energy saving jobbies...
[Edited on 2/12/09 by tegwin]
remove all bulbs and see.
Beware! Bourettes is binfectious.
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SteveWalker
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| posted on 2/12/09 at 10:38 PM |
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quote:
Originally posted by JoelP
a spark would firstly disconnect the light circuit from the board and test the insulation. He could then seperate individual runs and test lengths
seperately, to see if its a general old cable problem or something specific.
If it trips with the lights all turned off it would suggest a neutral to earth fault somewhere, but i would agree that the long consistant delay does
sound like something specific.
In the short term you could remove the lights off the RCD, but id hesitate to suggest that without also saying you need it testing and fixing
properly.
I certainly wouldn't be happy using that circuit until it's been properly checked and repaired.
I'm suprised that the lights are actually on an RCD though, unless it has been added before a consumer unit that doesn't have space for
one internally. Until recently lights were never normally put on the RCD, as it was considered dangerous to have your lights going out suddenly when
you got a shock off an appliance. The 17th edition regs now do recommend the lights to be on an RCD, but the idea is to have two RCDs, one doing the
upstairs sockets and downstairs lights and the other doing the reverse.
Just by coincidence we had a problem with our downstairs ring tripping the RCD tonight. Oddly, the only fault I could find was a terminal screw that
wasn't completely tight on the live for a socket - that shouldn't trip an RCD, but it was doing.
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tegwin
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| posted on 2/12/09 at 10:50 PM |
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The RCD is between the meter and the consumer unit.. (consumer is a retro bakelite affair with ceramic wire fuses)
I am imagining the consumer unit is about 30 years old, with some of the cabling a fair bit older!
The consumer unit only has 1 5A fuse with 2 live cables heading off into the wall.. I guess one for 1st floor and one for ground floor, but in this
house who knows!
How does a spark test the insulation?
If I knew the problem was consistant and fixed I would be confident at disconnecting each segment of the lighting ring and testing for shorts, but
because it seems to need some heat or somesuch to trip... this method would not work...
Anyone care to scare me with how much an electrician would charge for fault finding?
I am scared to invite one into the house because I am sure they will want to re-wire and replace a lot of the circuits and hardware... (would
make sence, but I dont want to have to destroy the house for the sake of it!)
[Edited on 2/12/09 by tegwin]
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Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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JoelP
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| posted on 2/12/09 at 10:55 PM |
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an electrical test meter has a mode where it applies 250v or 500v and measures resistance in mega Ohms. Current limited to 1mA for safety. My meter
reads >1000 on a new circuit. Older ones will drop to single digits. 2MOhms is the fail point, though you could work out how low it would have to
go to trip a 30mA RCD.
Seeing as there is a delay, it may be that all the circuits are borderline, and you could prolong their lives by seperating them onto two or more
RCDs, thus giving you more space for earth leakage without compromising safety.
How many fuses are there all in?
Beware! Bourettes is binfectious.
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tegwin
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| posted on 2/12/09 at 11:09 PM |
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There are 8 fuses in the Consumer board.
15A imersion
5A- Lights
5A Wall fire
5A wall fire
30A- Socket ring
30A socket Ring
30-Socket Ring
30A cooker (disconnected)
The issue is that the RCD is next to the meter in the porch, the consumer unit is about 10 meters away in the hall... I would have to remove the porch
mounted RCD and fit a new split load consumer unit with two fuses for the lighting circuit....
But I would be very concerned as to why the origional setup wasnt working.... giving it more scope to get hot and potentially start a fire is not
good news......
hmm... just looking at insulation/earth testing gear... £200 odd quid.... might be a worth while investment........
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Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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mad4x4
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| posted on 3/12/09 at 07:02 AM |
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Usually the Lights are not through an RCD
Scot's do it better in Kilts.
MK INDY's Don't Self Centre Regardless of MK Setting !
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tegwin
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| posted on 3/12/09 at 09:09 AM |
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quote:
Originally posted by mad4x4
Usually the Lights are not through an RCD
Houses of a certain age tend to! Mine does....lol...
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Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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JoelP
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| posted on 3/12/09 at 06:29 PM |
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new ones too with the 17th edition, ANY cable buried in plaster must either be on an rcd or armoured well enough to protect from nails and drills.
Id only buy test equiptment if you intend to do the rewire yourself - which lets be honest, its going to need it one day. Would just need to notify
building control, they may accept your certificates, or they may choose to test at their own expense.
Beware! Bourettes is binfectious.
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Liam
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| posted on 3/12/09 at 06:51 PM |
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quote:
Originally posted by JoelP
Would just need to notify building control, they may accept your certificates, or they may choose to test at their own expense.
Or they may refuse and demand you pay for a PIR yourself, on top of their fees Depends how crooked your LABC are.
If you really still have rubber cable left  (in that lighting circuit?), that could be a likely culprit. You might still want to confirm cable or
fittings by disconnecting all light fittings and putting them back one by one.
Yep, a spark coming to test your installation would certainly suggest replacing it, and quite right by the sound of it - sounds like a right mess.
Liam
[Edited on 3/12/09 by Liam]
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MakeEverything
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| posted on 3/12/09 at 06:57 PM |
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quote:
Originally posted by big-vee-twin
All electrical equipment has some leakage to earth especially computers and cooker elements also transformers.
Not all. Double insulated equipment, or equipment that has no earth cannot leak to earth.
You dont need to notify building control if rewiring, as it does not fall under Part P of the building regulations due to it being a
"replacement of existing", though get a qualified sparks in to rewire it, as he will be able to produce test certification and a
warranty.
The problem sounds to me like a water problem, but knowing what the equipment is thats tripping would be useful.
As Big-Vee-Twin said, RCD's are preset to 'trip' at 30mA when earth leakage is detected, so this would occur if water were present
within a light fitting, doorbell, garage etc.
Just because its a lighting circuit, doesnt mean that its a light thats causing it, unless you know for sure where everything is fed from. Ive seen
some real horror stories, and have experienced problems with this in the past - particularly on domestic installations.
Get a picture up if you can. It might shed some light () on things.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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