Sparking socket

[Foxy1991]

Hi everyone

I apologise if don't know all the correct world's to describe my issue but here goes 

2 days ago I had a vent drilled into my chimney breast inside as my previous owners of the house had decided to seal up the old fire place and not leave a vent. There is a single plug socket on the chimney breast to the very left side front of the breast. The vent was put in in the middle. But an SDS drill was used. 

Yesterday my downstairs sockets ring tripped (same place as the chimney that was vented) I turned it back on and hour later tripped again. Turned it back on for a second time and it was fine all night. I woke up today and came downstairs to find it off again. Soon as I turned it back on bang straight off again this time. So I turned all sockets off downstairs and turned the trio back on and it stayed on. I proceed to turn all sockets back on 1 by 1 and then they one on the chimney breast and as soon as I did it made a loud bang and yellow sparks came out of the socket and it tripped off again. 

Any idea what this could be? If I leave the socket off and then the rest back on everything is fine. What would this usually indicate is this issue? 

My first thought was that the live is connection with the ground in the socket maybe due to the vibration from the drilling close by. Would it be best to take the socket off and have a look if I can see any issues? 

Many thanks for advice.

 

[ProDave]

Probably a loose wire in the back of the socket.  Chances are the terminals were a bit loose and the vibration from the SDS made a wire pop out.

If you feel competent, turn ALL the power off and unscrew the socket to have a look at what you find begind it.

 

[Foxy1991]

Probably a loose wire in the back of the socket.  Chances are the terminals were a bit loose and the vibration from the SDS made a wire pop out.

If you feel competent, turn ALL the power off and unscrew the socket to have a look at what you find begind it.

Thanks for the reply ProDave. I had a look and before I even took the screws out I noticed some corrosion on the screw heads. Upon taking the socket away from the wall there was some more on the back box . So I think venting the flue was much needed! The wires all look fine its just the metal back box that also seems to have passed the corrosion onto the screws and then onto the socket itself. I'm going to go out and get a new back box and socket shortly and replace it. So fingers crossed everything will be okay now the flue is correctly vented. 

 

[Geoff1946]

Having lived in old property for many years I would warn you that damp masonry takes a long time to dry out. If it's not too visually objectionable you may be better with a surface insulated box and socket.

Also, if it's downstairs the damp is more likely to be rising damp through a dodgy damp=proof membrane. than due to the flue being blocked; that's more likely to cause upstairs problems. There are many layers of brickwork in a chimney breast and I think the old builders were fairly casual with such things as DPC,  perhaps assuming the heat of the fire would keep the wall dry.

 

[Foxy1991]

Many thanks I will look into a surface box! I'm not too sure it is rising damp. I've had no issues on the rest of the wall. I have also checked the other sockets and found no signs of corrosion and no tide marks or anything I read are a sign of rising damp. Just the flue that wasn't vented at the bottom. the other 3 fireplaces were sealed but vented and have no problems at all. 

 

[Geoff1946]

OK, I'm not out to scare you.

In my old (1920s) house the chimney breasts and entrance hall were prone to rising damp. These were of course solid, the rest being suspended floors.

Investigation showed that they had all been infilled with building rubble with no regard for damp-proofing. Just be aware that jerry building isn't a new concept!

 

[poni]

I proceed to turn all sockets back on 1 by 1 and then they one on the chimney breast and as soon as I did it made a loud bang and yellow sparks came out of the socket and it tripped off again

would you have a photo of this socket ,because just turning on a socket should not cause a circuit to trip on overload and spark, if its a socket it could be filled with water (replace with new socket job done) if its not a socket then its anyone's guess, could it be a switched fused connection unit (spur unit) this would have a second cable going out to something else and this cable could have been cut while cutting the hole in the wall

 

[Foxy1991]

Yep I will upload an image now. The cables look fine. The back box obviously corroded and there is corrosion on the screws (that I removed in that photo) also I noticed a screw on the back of the socket plate was rusted too. See to the left of the earth terminal. 

 

[Foxy1991]

And I should say no issues with the socket when its turned off on the switch on the socket. Only when I switched it on did it trip and spark. I had plugged an extension cable in to it, although nothing was connected to the extension cable. I have tried the extension in another socket and no issues. I haven't used the socket / turned it on for maybe over a year so the issue might have been present for a while 

 

[SPECIAL LOCATION]

Is that a decorative metal faceplate on that socket..?

Did the bod doing the SDS drilling use this socket to plug their drill in..?

Does the rocker switch feel a positive robust movement, or is it a bit stiff/loose/non-positive...?

It could possibly be something bridging internally between a live part and the metal faceplate due to one or more factors such as;

Build up of Damp, Dust, Corrosion, Deterioration of switch mechanism, Internal damage to insulated parts between metal earthed faceplate..

Something physically pushed out of shape by a poor quality shutter mechanism and a heavy-handed plug insertion...  

Its possibly being deteriorating for years.. and IF the SDS bod did use it for their drilling, it could have been the straw that broke the camels back.. 

I had to replace a metal fused spur this week due to something internal in the switch failing...

this fault was also causing combinations of tripping an RCD and/or a 32A MCB..  (with a bang and a spark)..

Yet the spur has never been electrically overloaded as it only supplied a single gang 13A socket!

Some of these modern decorative metal front accessories can have very cheap and nasty switches, terminals and generally poor plastic parts!

Guinness        

 

[binky]

And I should say no issues with the socket when its turned off on the switch on the socket. Only when I switched it on did it trip and spark. I had plugged an extension cable in to it, although nothing was connected to the extension cable. I have tried the extension in another socket and no issues. I haven't used the socket / turned it on for maybe over a year so the issue might have been present for a while 

in that case a new socket would probably sort out the issue.

 

[binky]

Having lived in old property for many years I would warn you that damp masonry takes a long time to dry out. If it's not too visually objectionable you may be better with a surface insulated box and socket.

Also, if it's downstairs the damp is more likely to be rising damp through a dodgy damp=proof membrane. than due to the flue being blocked; that's more likely to cause upstairs problems. There are many layers of brickwork in a chimney breast and I think the old builders were fairly casual with such things as DPC,  perhaps assuming the heat of the fire would keep the wall dry.

my house is 1886, on particulalrly wet winter a few years ago we got damp on the ground floor fireplace which could only have come down the chimney. I have a 4ft void under the floorboards which was bone dry. I have sinced capped the unused chimney pots with vented covers, ad fitted chinmney cowls to the 2 we stil use for woodburners, which seems to have stopped the problem coming back. I did offer to cap the neighbours pots whilst I had the scffolding up (they have 4 pots sharing the same stack) but they declined the offer, so I'm just hoping their 4 large holes don't let damp into my side again. 

 

[Foxy1991]

Thanks for all responses, most interesting to me. Yep it is a decorative metal faceplate and yep you guessed it the drill was used in that socket . What I've now done is replaced the back box with a plastic one. I've then used a terminal blocks on the wires. Taped them up in electrical and then waterproof tape and put a blanking off plate on the front instead of a socket for the time being. As others have stated the chimney could take a very long time to dry out and its not a socket I need anyway. So I thought while there may be some moisture I might as well refrain from putting another socket it on there. As well as venting at the bottom I am currently waiting for a roofing company to come and fit some vented caps on the chimney pots. Stop any rain getting in and the 2 birds that have fallen down there since I moved in! Hopefully once done it will eventually dry up maybe after a year and I can reinstate the socket 

For anyone interested I did open up the socket back cover and have a look inside. Not quite sure what I am looking at but it does seem quite burnt. I'll add some images of what it was like. 

 

[Phoenix]

If you look on the left hand side of the second picture, you can see a 'bite' mising out of the side of the two copper bars that take Live and Neutral from the switch to the socket contacts, this has where it has flashed across and you can see in the picture above heat damage on the plastic from this. Somehting must have facilitated the arc to strike, maybe condenstation mixed with dust, pure condensed water shouldn't do it, but if dust was present then the wet dusty residue could easily do it. Once an arc is struck there is a propensity for it to try and continue, the air itself becomes conductive as it becomes ionised. Obviously at this point the cirucity breaker opens to disconnect the circuit (which indecentally causes an arc in that as it opens, but this gets channelled down an 'arc chute' where it is is down out to a series of smaller arcs between plates which are widened and cooled until it goes out - fuses are more simple, they are packed with sand which occupies the space where the fuse element was in order to break the arc)