16A Commando socket question.

[PaulieN]

New here so hello everyone.

I have a stupid question for you all. Would like to know the answer from a safety point of view as well as current compliance point of view. I am a qualified electrician but left the profession way back in 1994 for a more lucrative profession, so rusty to say the least.

The garage of my new house has a 2.5mm T&E radial circuit feeding half a dozen double sockets. Fine with this as it's just at 50m2, so OK there and the number of sockets is for convenience, load won't be over the 20A, so all good so far. Along side one of the sockets is a 16A commando. This is wired into the radial along with the 13A's.

I can't find a reason why this isn't OK, but likewise can find no guidance to say it is either. In an ideal world I'd have it on it's own 16A circuit, but the regs state 16A's are OK on multiple socket 20A protected circuits but don't seem to specify a limitation to the type of sockets. The job is beautifully done in plastic conduit to eaves height everywhere and then the neatest clipping you've ever seen along the rafters to a 2 gang CU with the 20A radial and a 6A lighting circuit. Changing the CU to something wider isn't desirable as it fits perfectly in a recess behind the doors.

Any thoughts?

 

[ProDave]

Change the 20A mcb to 25A  to get the most from that radial circuit.

Or it it's never tripping, leave it as it is.

 

[PaulieN]

Thanks for the quick feedback! Can't though, the SWA feeding the garage is only 2.5mm and the length of run is borderline for voltage drop with a 20A, so I'm stuck with it, as I'm not digging up 25M of block paving and concrete to upgrade it. lol!! It's protected at the main CU in the house with a 25A MCB due to this. The garage lighting load with everything on is 3.6A, so I'm way out of spec if I upped it to 25A. 

I'm OK with 20A, and disciplined enough to minimise other use if I'm using my welder in the 16A socket. It's just niggling at the back of my head that it's not compliant.... just would like a definitive as to why not if it isn't I suppose. Was done in around 2013 I think, so might be OK for the time, but not now due to current part P nonsense? 

 

[Sharpend]

Part p came about in 2004/5 so not an issue there. 

I wonder if this commando was put in by specific request perhaps for a caravan? 

 

[Andy™]

553.1.201 may apply

Every socket-outlet for household and similar use shall be of the shuttered type and, for an a.c.
installation, shall preferably be of a type complying with BS 1363.

 

[Evans Electric]

Does your welder work from a 13A socket ?   Or do you need the 16A Commando  for it?

Have to say , if it doesn't trip , leave it alone  it sounds safe enough other than no mention of  RCD .

May be some VD  but as you say ...you're not going to dig up the patio. 

 

[binky]

I really don't understand what you think the problem is? A twin socket could have 2off 13A appliances plugged in.

 

[PaulieN]

Thanks for the replies. Not really worried about it, just curious if it is to regs. Never come across it before. Of course definitely wouldn't comply if on a 32A ring, but as the circuit is a 20A radial it sits OK with regs for protection at least. Shutter may be a good point. I wonder if it's still classed as household use though as it's a seperate garage? Doesn't worry me at all as there's no access to children and, yes it's all covered by a 30mA RCD. 

Previous owner did have a caravan and the socket is nearest to the door, so probably was used for a hook up thinking about it.

The welder does need 16a, it pops 13a fuses when it feels in the mood! 

 

[Andy™]

thats the thing, 7671 doesnt define household use. so imo in a garage isnt 'household use'

worst case, you can get interlocked versions so you cant turn on the power unless there is a plug inserted which would comply. many welders do tend to pop 13a fuses too, although inverter ones on a lower setting are usually OK

 

[Adrian]

So you over current protection for that 16amp socket is the 20 MCB that can't be right 

 

[Andy™]

So you over current protection for that 16amp socket is the 20 MCB that can't be right 

OSG says otherwise. allows a 16a on a 20a OCPD

 

[PaulieN]

Regs say (unless 18th edition has altered this!) 1, 16A on a radial circuit should be a protected at 16A,, multiple 16A can be on a radial protected at 20A, so that's OK, just no specifics on mixing socket types, but doesn't state you can't!

 

[Adrian]

Seems they need to redefine the socket and call it 20 amps. or better still say each outlet must have 16 amp ocpd provided at evey point 

 

[Murdoch]

I really don't understand what you think the problem is? A twin socket could have 2 off 13A appliances plugged in.

and not last very long!

Seems they need to redefine the socket and call it 20 amps. or better still say each outlet must have 16 amp ocpd provided at evey point 

Ah the delights of BS 7671 - written by people who never get their hands dirty, so have no idea how poorly they are worded, or interpreted....

I would say that the 16A commando should be protected by a 16A MCB...........probably a type C

 

[kerching]

The regs are an ass in places

16A commando on 20A breaker....wrong

2 x 16A commandos next to each other BUT you will only EVER use one of them because you only have ONE welder and have no intention of buying anything else....complies

just saying

 

[PaulieN]

Yep, It's crazy. I've decided it's staying exactly as it is now lol!!

 

[Adrian]

I really don't understand what you think the problem is? A twin socket could have 2off 13A appliances plugged in.

Your plug has a 13 amp fuse fitted for protection the 16 amp commando socket has none 

 

[Tony S]

BS1363 only calls for 13A in one outlet and 10A in the other. Total, 23A.

 

[PaulieN]

BS1363 only calls for 13A in one outlet and 10A in the other. Total, 23A.

Which is a ridiculous and non enforceable regulation as joe public will happily plug in 2, 13A appliances, blissfully ignorant of this restriction!

 

[kerching]

I think sockets have 20A max stamped on the rear WHICH EVERYONE SEES  :slap