main fuse

[humblebum]

was checking the main fuse to a domestic consumer unit and the fuse is a two offset bladed type and rewireable. the wire is 1.2mm in diameter which is bigger than I expected. anyone know what this equates to in amps or is there a table somewhere I could look up? is this also classed as bs3036? thanks for any help

 

[the_jinj]

I would guess it would be best to just change it for what it should be if not sure - I do recall welding wire comes in 1.2mm - hope it ain't that

 

[RF Lighting]

What were you checking the fuse for? Are you allowed to pull REC fuses? If the fuse rating is not correct then it is the responsibility of the REC to sort it out not you.

And yes it will be a BS3036 fuse.

 

[humblebum]

if there is no seal on them I will pull them to see what is fitted, as what it says on the cover is not always what is in it. allowed? well no, but some things in life require us to cross the line a bit to do a proper job.
I'm not saying the fuse is anyone's responsibility except the supplier but before passing it on to the customer it would be nice to be factual as against a vague "the main fuse may be dodgy" (i'm not training to be a surveyor)
I am enquiring for information to help me establish the rating I should expect from such a diameter. A 30A fusewire is about 0.8mm dia giving a csa of about 0.5mm2. 1.2mm dia would give a csa of 1.13mm2, so on a ratio of current to area it would equate to about 68A. However I don't know much about rewireable characteristics and was hoping someone could help.

 

[baldersj]

Table 53A in the regs (Pg.108) puts a 1.25mm fuse wire in 45A fuse. Mind you, that's the rating of the fuse, not the maximum capacity of the wire, which is probably why it hasn't already blown. I would imagine a main fuse would need a bigger wire, somewhere in the region of 1.8mm?

 

[humblebum]

thanks mate that was the table I was after....just couldn't remember where I'd seen it before (or if I had just imagined it!).
The new key meters....does the tenant take the key to the shop and the money gets credited on to the key?

 

[baldersj]

Yes

 

[Steve]

bring on key meters!!!! tokens are going out of fashion slowly but surely! not before time!!!

 

[cozycats]

I've never seen a rewirable main fuse how old is it ??? sounds like a museum piece!!!! had an edf guy showing me his private collection of fuses recently( I know sad but everyone should have a hobby!), but his oldest (1934) was a cartridge type fuse! !!

 

[RF Lighting]

I've come across quite a few. The are usually rated at 30A, made of ceramic and housed in a painted green cast iron enclosure. These cutouts tent to be laced with asbestos (flashpads, fusewire tubes, seperators and enclosure lining) so extreme care should be taken when working on these cutouts.