Downgrading cable size

[magnoliafan89]

Hi guys

I was doing a kitchen recently and behind the cooker hood I had ran 2.5mm from a FCU, the hood can with 1.5mm flex. I had put a plug top with a 3amp fuse onto the flex and then a single socket for the 2.5. That way you just plug it in.
The kitchen fitter got all assy and said that his normal electrician normally just shoves a junction box up there and it looked stupid having a socket and kept asking why I did it.
I said my reasoning being that a junction box on a new install is RAF and that I couldn't just downgrade the cable size without fusing it down.
I've never been shown a reg saying about the cable size, is this just a preference thing or is it actually what should be done??

 

[radiohead]

The overload and fault protection must be adequate for the chosen cable, and load. Why 2.5mm from a fused connection unit? It'll be fused at a maximum of 13a so 1.5 would suffice. If you ran from an FCU then it's fused there isn't it? Nothing wrong with your method though, but effectively the load is fused twice. I often just use a blue Clik connector for the cable to flex joint, with a 3a fuse in the FCU.
Best tell Kev to do one though, are you telling him how to screw a cabinet to the wall?

 

[Midwest]

I used to get similar comments. You can try and educate, but might be simpler to explain, that appliance ‘engineers’ won’t touch anything they can’t psychically disconnect, when it comes to repair.

 

[radiohead]

I once ran 1.5mm cable from FCU's to the appliances sockets directly below only for Kev to tell the client that it was 'illegal', it had to be 2.5mm. The thing is the client invariably believes Kev....every time.
Some of them need a slap.

 

[magnoliafan89]

Long story short it was one of the legs of the ring til we changed the routing and as it was already hugh level i left this in to be the feed.
I hate that word when describing electrical work "illegal" whenever I get someone telling me they've done their research so know somethings illegal I dunno whether to laugh or slap them

 

[Andy78]

So the supply for the hood came from a FCU but you needed to fuse down where the cable connected to the appliance flex ?
Why not fuse appropriately at the FCU ?

 

[magnoliafan89]

So the supply for the hood came from a FCU but you needed to fuse down where the cable connected to the appliance flex ?
Why not fuse appropriately at the FCU ?

Because I'm an electrician and that means we can do what we want ??

 

[Andy78]

Because I'm an electrician and that means we can do what we want ??

I think I'd have to agree with the kitchen fitter if that's the reason then.

 

[magnoliafan89]

Personally I just really dont like the idea of a junction box or d box on a new install. I was always taught throughout my apprenticeship and then carried into my years as a spark that when doing a new install any join like that is rough.

 

[MJPD29]

Its fused at the FCU. I would have out the 3a fuse in there if thay is what you require. Where did you put the socket? If its in view i wouldn't want it in my kitchen either. Its its hidden on top of the cupboards or inside the duct cover from the hood then it makes no difference.

 

[Andy78]

Personally I just really dont like the idea of a junction box or d box on a new install. I was always taught throughout my apprenticeship and then carried into my years as a spark that when doing a new install any join like that is rough.

A clik flow plug or a flex outlet plate would be my preference to putting an unnecessary fuse in.

 

[magnoliafan89]

Its fused at the FCU. I would have out the 3a fuse in there if thay is what you require. Where did you put the socket? If its in view i wouldn't want it in my kitchen either. Its its hidden on top of the cupboards or inside the duct cover from the hood then it makes no difference.

It's in the duct so out of view

 

[MJPD29]

It's in the duct so out of view

Then I cant see what his problem is tell him to worry about his own job. If anything its now easier to isolate if it needs changed. Problem is if it blows it's difficult to change as you have to take the cover off.

 

[magnoliafan89]

A clik flow plug or a flex outlet plate would be my preference to putting an unnecessary fuse in.

He just didn't want any sort of that box in...hes just so used to the standard black round JB. He thought it odd putting in a switch for the fridge and dishwasher above the counter

 

[radiohead]

Then I cant see what his problem is tell him to worry about his own job. If anything its now easier to isolate if it needs changed. Problem is if it blows it's difficult to change as you have to take the cover off.

This is a very good point, a friend of mine had a stainless chimney type extractor with a plug in behind, GU10 lamp blew and took the fuse out. Kev had mastic'd all round the chimney which made it a right ball ache to get to.