socket

[Buzz-light-bulb]

Little scenario for you all.

I've been doing an eicr today and come across a double socket wired as a radial on a 2.5mm t-e, which is protected by a 32 amp rcbo.
Technically this cannot overload as the cable can withstand 27 amp ref method c. Unless mr DIY comes along and starts adding new sockets which I am not responsible for so my question is would you leave it

 

[Hawkmoon]

I've always thought that the sole purpose of the Fuse/MCB was to protect the cable ie the MCB needs to be equal to or less than the maximum current carrying capacity of the cable. So in this case, the 32A MCB is not suitable.....

Overload protection does not have to be at the origin of the circuit...

 

[NickD]

Yes, because it is total crap!! lol

But with an ickle maggot of truth wiggling about in it.

 

[jaypp]

deleted.

 

[Hawkmoon]

So based on this assumption I could wire a single 13A socket on the end of some 1mm cable from a 50A MCB in the CU?

No, because even though, in your example, overload considerations may be met (though doubtful), thermal constraints (cpc fault current) certainly are not.

 

[dazza1981]

Overload protection does not have to be at the origin of the circuit...

So you think its ok to have a 1.5mm cable protected by a 50 amp breaker???

 

[7029 dave]

The op of this thread EICR different story, BUT to create a radial 2.5mm backed by 32amp mcb, come on basic electrical craft principles never mind 1.5mm, and all this talk about relying on fused appliance's to protect the CIRCUIT against overload current is crab.!!!

 

[gazj82]

No, but it is ok to have protected by a 13a plugtop fuse at the end of the circuit is as far as overload is concerned.

 

[HappyHippyDad]

I certainly wouldn't advocate the scenario, and have always worked on the basis of MCB egual or less than CCC of cable. I have always replaced 'offending' MCB's in the past with something more 'suitable' but maybe I've been over cautious? I don't get involved with EICR's so don't have the dilemma of which code is 'appropriate'

I wouldn't say that.. I'd say "sensible".

 

[Badged01]

Have a look in some industrial busbar chambers for how conductors are protected coming off the busbar against overload (and fault) ......

 

[gazj82]

Dave, you cannot load the CIRCUIT any higher than 13A, unless you are abusing the plug and socket system

 

[dazza1981]

Ok i will just use any breaker i have spare in the van for any circuit then provided its fused at the end of the circuit somewhere

 

[gazj82]

Ok i will just use any breaker i have spare in the van for any circuit then provided its fused at the end of the circuit somewhere

The cable would be protected against overload - IF

It only served one piece of equipment at the end of it's run and nothing on the way, so you can't have a radial with 3 double sockets on it obviously.

Obviously you can't have a 16A socket at the end because these have no fuse system, but you could have one 13A socket or one switch fuse (fused appropriately for the cable)


I am not saying I go out of my way to install like this, I use an appropriate sized MCB at the origin like anyone else, but technically you don't have to.

 

[Hawkmoon]

Ok i will just use any breaker i have spare in the van for any circuit then provided its fused at the end of the circuit somewhere

But then you are giving no consideration to thermal constraints...

Producing extreme and ridiculous examples does nothing to contribute to this debate...IF overload and thermal constraint limitations are met, it complies with BS7671 so no code, no comment :13:

Why do you think it is acceptable to install a 2.5 spur from an RFC?

 

[Badged01]

Ok i will just use any breaker i have spare in the van for any circuit then provided its fused at the end of the circuit somewhere

You need to be careful there or that 6A breaker you put in might keep tripping every time they put the shower on .......

 

[dazza1981]

You need to be careful there or that 6A breaker you put in might keep tripping every time they put the shower on .......

You know what i was getting at badged