Fuse box sparking

[latix]

Last night I was wiring up a new socket in the kitchen, the wiring was correct because I had the new wires connected in a chocolate block while the plaster around the switch box set and everything worked fine.

Once the plaster had set I connected the new switch up and turned on the electricity. Everything was fine until I plugged in the kettle into an existing socket and I heard a fizzing noise. I went to turn the electricity off and noticed the fizzing was coming from behind the main fuse box and I could also see sparks. I re-checked the wiring in the new switch and everything seemed fine but i gave a bit more slack in the wire and screwed it back up, now everything seems fine.

What I would like to know is:

a) Why was my fuse box fizzing
b) Shouldnt the fuse wire in the fuse box have blown? It had 30amp fuse wire in it, is this the correct size?

 

[Chivers7]

What type of circuit is it ring/radial?
What is the conductor size?
What type of fuse is it?

As there was some kind of fault between the insulation i'd imagine? Or loose connection.

Edit just reread "had 30 amp fuse wire in it" so this is a rewireable type Wylex or something?

 

[JohnD]

You mention 30A fuse wire.

this tels me that it is probably a rather old fusebox, most likely a Wylex Standard in brown or cream.

a fizzing fusebox suggests a loose connection inside it. Sometimes you only hear them when they are carrying a large current. A kettle is a heavy load, and if you had another heavy load operating at the same time (washing machine, tumble drier, oven, dishwasher, toaster) this may be the reason you heard it once but not again. Sometimes the main switches in these old units wear out and get loose.

Fizzing and sparks indicate a problem that needs fixing. Left to itself it will get worse not better and there is a risk of fire.

Can you post a pic of your fusebox and the area around it, including the meter and cables? this will give us more ideas.

 

[latix]

Will get a picture sorted tonight but the fuse box has been built around so i dont think you can see the wires.

Can the wires to the fuse box be easilt tightened or do I need to get a qualified electrician to do it?

 

[Chri5]

Fuse boards are quite dangerous places, if you don't feel confident it's best left to someone who is.

If you do decide to do it, isolate the fuse board by turning the supply off at the fuse board (and the meter, if you have further isolation).

Check and double check that the isolation is correct with a meter.

Then check every live, every neutral and every earth termination and make sure every one is screwed tightly. Also check all mounting rails for tightness, and every fuse carrier for tightness on to the power bar.

Visually, if you see any burn marks caused by arcing, then that would explain the buzzing noise you heard when the circuit was under load.

 

[davelx]

Don't forget that the tails coming into the CU from the meter will still be live even if the main switch on the CU is off. Depending on the age of the CU, these may be exposed at the top right of the CU (old brown wylex)

If you suspect one of these is loose, do not attempt to tighten it unless you are confident that you know what you are doing/how to do it safely and have proper VDE rated instulated tools! I'd suggest that you don't try wiggling the tails to see if they are loose - the live one may just come out and then you have a problem!

 

[CallEdsFirst]

Last night I was wiring up a new socket in the kitchen, the wiring was correct because I had the new wires connected in a chocolate block while the plaster around the switch box set and everything worked fine.

Its definitely done correctly then! No earth faults here! (that wouldn't get picked up by a board that still has rewirables in it and almost certainly no RCD!)

Once the plaster had set I connected the new switch up and turned on the electricity. Everything was fine until I plugged in the kettle into an existing socket and I heard a fizzing noise. I went to turn the electricity off and noticed the fizzing was coming from behind the main fuse box and I could also see sparks. I re-checked the wiring in the new switch and everything seemed fine but i gave a bit more slack in the wire and screwed it back up, now everything seems fine.

If in doubt, bit more slack always helps!

What I would like to know is:

a) Why was my fuse box fizzing
b) Shouldnt the fuse wire in the fuse box have blown? It had 30amp fuse wire in it, is this the correct size?

What I would like to know is if flames started licking out of your bonnet whilst you were driving, but stopped as you took your foot off the gas, would you go to a garage or carry on as normal?

 

[Chivers7]

What I would like to know is if flames started licking out of your bonnet whilst you were driving, but stopped as you took your foot off the gas, would you go to a garage or carry on as normal?

depends if it was a dragster I suppose

 

[CallEdsFirst]

What I would like to know is if flames started licking out of your bonnet whilst you were driving, but stopped as you took your foot off the gas, would you go to a garage or carry on as normal?

depends if it was a dragster I suppose

Yes, agreed! Lets hope the OP's CU isnt also full of alcohol fuel!