4mm on 32a mcb??

[KNIPEX]

Just a quick question for you lot.

would you put 4mm t+e cable on a 32a mcb.

or would you play it safe and stick it on a 20a mcb.

thanks in advance.

 

[sparkyork]

4mm can take 32a dont know the exact pages in on suite guide etc but its ok, also alot of the old houses out there are 4mm radials etc.

 

[EasyFox]

Yes no problem at all.
I have on occaion wired 4mm radials in kitchens with 32amp ocpd's, with rest of house divided up into 2.5mm radials with 16 / 20 amp ocpd's.

 

[jeremy]

Wouldn't do it my self but I'm sure someone could say if it's clipped direct with ice round it it would be ok forever. What if the ice melts? your'e signing for the situation as you find it . do how bankrobbers practice and play safe

 

[Cirrus]

Yup yup it is fine. Portakabin always do it although it is tiring terminating 200 sockets in 4mm twin & skin

 

[sparkyork]

yep same as easy says, kitchens is where ive mainly used a 4mm radial, id use a 35mm back box as well to ease installation. also on a slight tangent! mk's dbl sockets are actually recommended to be installed in 35mm boxes but more often than not are done in 25mm's boxes's

 

[Dinosaur]

4mm clipped direct has a current rating of 37 amps, all other installation methods drop that rating down below 32 amps.

Ib<In<Iz ..... ?

 

[Shakey]

Wouldn't do it my self but I'm sure someone could say if it's clipped direct with ice round it it would be ok forever. What if the ice melts? your'e signing for the situation as you find it . do how bankrobbers practice and play safe

why wouldnt you do it? it is a perfectly acceptable design solution, and the regs (both 16 and 17th) expressly say you can do it.

i have just put a 4mm radial into a kitchen - what you you say if you found that on a PIR then

 

[Mossy]

Sure it all depends on the lenght of the cable. it would be ok for a short run. you should work out your volt drop on the cable before anything.

 

[Shakey]

Sure it all depends on the lenght of the cable. it would be ok for a short run. you should work out your volt drop on the cable before anything.

well of course, but whats that got to do with 4mm on a 32A MCB? dont you (we) do that with any cable we design and install?

the regs tell us we can serve an area of 75 metres squared with 4 mm on 32A MCB.

I have done a number of 4mm radials recently, and shall continue to do so

 

[BEN5637]

4mm cable, radial circuit, 32a mcb. nothing wrong with that

 

[Jurassic Spark]

In the 80' all showers (7.5 - 8.0kw) were installed using 4mm t&e cable on 30amp HRC fuses so no problem with the cable size.

 

[flukey]

Not sure what the problem is as this has always been common practice

 

[rumrunner]

In the 80' all showers (7.5 - 8.0kw) were installed using 4mm t&e cable on 30amp HRC fuses so no problem with the cable size.

Not all,i always used 6mm and so did everyone else as far as i know
and most often it was a rewireable fuse,HRC fuses were rare