Single 16A Commando On 20A Mcb

[Sidewinder]

I'm not on a witch hunt for the contractor by any means, they put me in there to do the additional investigations for them as they don't have anyone to do it!

It just "felt" wrong having a single 16A s.o. on an OCPD >16A!

They haven't picked it up.

My Engineering Report has gone in now, I've not said it is wrong and does not comply, I have effectively flagged it as requires FI if it were a BS7671 report.

 

[Marvo]

It's a standard installation where I am to have 16A sockets on a 20 or 25A radial, on C curve MCB's also with unfused plugs. The only only thing is appliance trailing cables, especially ones of low CSA need to be kept short. In the real world you can never limit the current of a socket to its design current without make multi-plugs illegal and the way I look at it you can never fully protect an installation against abuse by the user.

 

[Phoenix]

AFAIK, it was the OSG that suggested one could have multiple 16A commando sockets on a 20A radial, but I never did find anything in the regs to back this up

I wouldn't install it, but I think I'd struggle to say that it was wrong in light of official IEE guidence saying differently!

I do recall having a slight discussion with a colleague upon finding a three phase 16A ceeform outlet for an oven had been connected to a C32 breaker on a job, eventually got agreement that it was wrong, but not sure it sunk in and concerned it might happen again!