EICR codes - school

[snipersmith87]

Any general purpose socket circuit has the same potential for overload. A twin socket on a 16A MCB could be overloaded the same way.

Commando sockets don't draw more current, they load connected to them draws the current.

Maybe I'm looking at it differently because it's perfectly normal for us to install 13A, 15A and 16A outlets on the same circuit.

I agree. However General purpose sockets do get overloaded. Extension leads get overloaded. Worse case scenario an overload that isnt enough to trip the ocpd and create a fire hazard. It does happen. We all design circuits to prevent overload or minimise it to short durations.
In my head a 16amp commando is to supply a piece of equipment that is potentially gonna draw more than 13amps....hence why its not on a 13amp plug top.
Put that load on a 16amp mcb. Along with a tea urn... etc etc. The mcb could be operating above its 'designed' loading due to additions over time.

 

[Dustydazzler]

I agree. However General purpose sockets do get overloaded. Extension leads get overloaded. Worse case scenario an overload that isnt enough to trip the ocpd and create a fire hazard. It does happen. We all design circuits to prevent overload or minimise it to short durations.
In my head a 16amp commando is to supply a piece of equipment that is potentially gonna draw more than 13amps....hence why its not on a 13amp plug top.
Put that load on a 16amp mcb. Along with a tea urn... etc etc. The mcb could be operating above its 'designed' loading due to additions over time.

Once you get to about 18-20 amps for even a relatively short period most 16a mcbs will operate. Most cable attached to a 16a device should be good for at least 20 amps for a good while.
I saw a test where JW put 80+ amps through some 1.5 csa cable and it took ages for it to start smoking and melt.
20 ish amps wouldn’t even make a dent

 

[davesparks]

I agree. However General purpose sockets do get overloaded. Extension leads get overloaded. Worse case scenario an overload that isnt enough to trip the ocpd and create a fire hazard. It does happen. We all design circuits to prevent overload or minimise it to short durations.
In my head a 16amp commando is to supply a piece of equipment that is potentially gonna draw more than 13amps....hence why its not on a 13amp plug top.
Put that load on a 16amp mcb. Along with a tea urn... etc etc. The mcb could be operating above its 'designed' loading due to additions over time.

Yes that could cause an overload, however the ocpd will operate according to its tripping curve.
The tripping time of the OCPD is taken in to account in the current rating of the cable, they don't reach ignition temperature the moment they see 0.1A more than the ocpd rating.

A 16A socket is used to supply anything with a 16A plug on it, there's more than one reason for doing this.

In the OP you say that it is currently supplying a 16-2x13A adaptor, so it's no different having another 13A twin socket on the circuit.
Yes the layout could change in the future, but then it could also stay the same for the next 10 years, that's unpredictable.
By this same logic you could say that any circuit could be altered in the future and therefore should be coded.

 

[snipersmith87]

Yes that could cause an overload, however the ocpd will operate according to its tripping curve.
The tripping time of the OCPD is taken in to account in the

Yes that could cause an overload, however the ocpd will operate according to its tripping curve.
The tripping time of the OCPD is taken in to account in the current rating of the cable, they don't reach ignition temperature the moment they see 0.1A more than the ocpd rating.

A 16A socket is used to supply anything with a 16A plug on it, there's more than one reason for doing this.

In the OP you say that it is currently supplying a 16-2x13A adaptor, so it's no different having another 13A twin socket on the circuit.
Yes the layout could change in the future, but then it could also stay the same for the next 10 years, that's unpredictable.
By this same logic you could say that any circuit could be altered in the future and therefore should be coded.

I agree Dave. Just overthinking as usual...(Or underthinking!)

 

[Lucien Nunes]

Which ever way, surely the 16A MCB protects? The same way in how any cable can be subject to overload despite being protected by an ocpd.

If the Iz of a cable is 16A after the necessary factors are applied, it means that it is large enough to be adequately protected by 16A OCPD, not that its absolute limit is 16A. In effect, a cable that the calcs say is derated to 16A will actually carry at least 16 x 1.45 = 23A. But you can't use it at that current if it's protected by (e.g.) a 60898 because to be guaranteed to trip at 23A, you have to use a 16A device which makes 16A the maximum usable Ib.

And re MICC, if that needs protection against school pupils, the school has bigger problems than its EICR results.

 

[Lister1987]

The Gray area that I have picked up on is, if you are able to plug an extension lead into a ground floor socket and take it outside, or corridor sockets where cleaners may be plugging in hoovers or floor polishing machines. Where I would still put this as a C3 but with a foot note explaining my findings and concerns.

So you replace them with RCD sockets and futureproof against stupid or would this be cost prohibitive?

 

[Deleted member 122525]

So you replace them with RCD sockets and futureproof against stupid or would this be cost prohibitive?

It would always be cheaper to put an RCD in its own enclosure next to the DB than RCD sockets, but you have to remember that this is an EICR only. The customers dose not have to act on your findings or recommendations, so you would discuss what you have found and talk over what are the most important faults to correct,

 

[7029 dave]

MICC, is very strong cable, remember at college many years ago lol, the Tutor hammered it flat IR the piece and it was perfect.