Help/advice Needed

[Tonyn]

I recently took the screws out of the lighting switch so I could paint around the light switch. On putting it back It sparked out causing the fuse wire in the 5 amp fuse to blow. After inspecting the light switch, with the power off, it appears that one of the screw heads from a live wire touched the metal box in the wall which has also knocked out all my downstairs lighting. upstairs is fine.

I have replaced the fuse wire and checked the wires on the switch to make sure they are tight. Switched the main fuse box back on but it still isn't working. I tried changing the switch to a new one, and it still doesnt work. I've checked the bulbs and they are all fine.

Can anyone give me any advice on what I can do to get my lights back on?

many thanks

 

[Marvo]

You're going to need test equipment to go any further and enough experience to interpret the results and to know how to work safely. I'd suggest getting a professional electrician to have a look, it sounds like it would be a straightforward matter of localising the fault so it shouldn't cost much. 

 

[Evans Electric]

1)   Can you see the black "blow" mark on the terminal screw  or could it have been a trapped wire ?   The wire could have blown apart .

      You've changed the switch so ruled that out .

2)   Re-check that the fuse wire is fitted properly . 

3)   As said , you need a tester of some sort to see if you have voltage at the switch .  but as  a DIYer  I have to urge great caution with power on .

      Phone a sparky.

4)     Are your electrics really really old .....I'm thinking wooden type fuse board with prcelain fuses ....you could possibly have a fuse in the neutral ...still a few about .

 

[Tonyn]

The house was built in the 70's and I would say that it's the original fuse box. The screw that touched the metal box is now black on top but as you say, I've changed the switch over. The fuse box is a plastic one and you can see the fuses on outside. I had to take the fuse out, replace the wire and put it back in again. What do mean by a fuse being in neutral?

 

[steptoe]

doubtful if there is a fuse in the neutral on a 70s install,

its most likely either wylex or MEM fuse box,

sounds very like either the wire has blown internally, or the fuse wire is incorrectly replaced,

check the fuse wire again, its very easy to break 5a fusewire when tightening the screw that holds it in place.

 

[kerching]

Have you got overenthusiastic and over tightened the screw on the fuse wire?

5a fuse wire is notorious for snapping.  Try wrapping the wire anti-clockwise around the screw head ( todays free tip!)

 other than that my money is on the wire having blown in two

 

[Tonyn]

Going to check the fuse in a minute. You say that the wire has blown, where do you think it has blown? Will I be able to see it?

 

[steptoe]

it may have blown just back slightly from the end,

try grabbing the wires at the switch with some pliers and give a gentle tug.

 

[SLIPSHOD & SLAPDASH]

Is it just the lights in that room, or all of them now not working ?

 

[ProDave]

I can't add anything to what has been said about tracing the fault.

All I will add, is this is a perfect example of why you must isolate the circuit (in this case by removing the fuse) before you do ANYTHING to it.

Just be thankful all you have is a blown fuse. Removing a live light switch could have resulted in a lot worse.

 

[Tonyn]

Just checked the fuse wire again and it had snapped in the middle, just couldn't see it without undoing it. New wire in, fuse back. Power on and bingo, the lights are back on. Many thanks for all your advice. Cheers

 

[Evans Electric]

No problem ...where do we send the bill ? 

 

[BlueFlashAsh]

just thought id add as no1 else did. you could of take then upstairs lighting fuse and put it in the downstaires to quickly test if you damaged the circuit or just hadent put the fuse wire in correctly.