13A FCU

[Fezzie]

Hi I would like to try and make the best of a bad wiring job, (not mine).

A company that built a conservatory onto the rear of a house took a spur out of a socket in the kitchen, This feeds two double sockets one light fitting and under floor heating all on what appears to be 2.5 t+e.

I was going to put an FCU in to at least protect the cable. But what i wanted to know is can the bs 1362 be used to meet the disconection times for the circuit after it, or does the Zs at the sockets lights etc have to meet the 1.12ohms for the 32a type b mcb that protects the original ring circuit.

(just trying to help a friend out would value an opinion,Cheers)

 

[plugwash]

can't see any reason why you can't rely on the bs1362 fuse for short cuircuit protection although you may find it doesn't really help you much in terms of short cuircuit protection anyway.

am i correct in thinking the reason you are putting it there is overload protection for the multiple sockets on the spur.

 

[Fezzie]

Just want it to be safe thats all. I thought that the 13A fcu would provide overload protection. (i'm not an expert hence my post).

(by the way its not just two sockets but lights and underfloor heating on one cable)

 

[Adam_151]

Max Z's for a 13A BS1362 is 2 and a half ohms for 0.4 second disconnection (I think*)

* you'd want to check this before using it tho

 

[Big_Spark]

Fezzie..How long ago was this work done??

It is totally unsafe and certainly does not comply with BS7671:2004.

Personally I would be inclined to call the company in that did it and ask for it to be corrected to BS 7671:2004 and that a Test Certificate be provided as is a requirement of both BS7671:2004 and the Building regs.

Multiple sockets are bad enough, but to run underfloor heating AND a light from a ring main with no overload protection except the circuit MCB is a disgrace.

 

[Fezzie]

back end of 2003 i think. Not sure if my friend wants to pursue it.
Makes you wonder what other jobs these people have done though.
I don't think its that they don't care, its just that they don't know any better.

(as i understand it every body is happy that the 13A fcu will protect the cable, and as long as Zs etc is ok then the installation will at least be safe if not perfect)

 

[plugwash]

yeah the fcu will protect the cable, i'd be tempted to also fuse down the lights to 3A with a seperate fcu though i belive this isn't strictly needed.

 

[Spark123]

yeah the fcu will protect the cable, i'd be tempted to also fuse down the lights to 3A with a seperate fcu though i belive this isn't strictly needed.

Yup, you never know if someone is going to install a SES or SBC light (regs = fused 6A max).

 

[Fezzie]

Thanks for your help all. decided on a 13A fcu/rcd to cover all bases (it is a conservatory so the sockets may well be used outside).
Checked the lights and there was an fcu but it had a 13A in it, i have changed it for a 3A. Once again thanks!