I say no, but, I have reservations, anyone any other opinions please?...
Single 16A Commando On 20A Mcb
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+1 on the no. As in In exceeds the current carrying capacities etc, the 16A rated pins coming under "conductors of the circuit". Chapter 43?
But then saying that..........a 1G socket on a 16A for an immersion is no different........
But then saying that..........a 1G socket on a 16A for an immersion is no different........
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regs say you can...
and most of the 16a sockets in my unit are on a 20a
and most of the 16a sockets in my unit are on a 20a
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Is it that if you look hard enough in the regs you can always find an ambiguous argument for/against anything and that it's all open to interpretation? :lol:
I don't think I'd do it, but the ocpd is only there to protect the cable,,, isn't it?
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Having just got my digital silver jobby, but not being able to drive it properly, it has vomited the following
C3
— —
the appliance is locally protected by a fuse to BS 1362, of a rating not exceeding 13 A, or the circuit is protected by a circuit-breaker of a rating not exceeding 16 A.
Radial final circuits using 16 A socket-outlets complying with BS EN 60309-2 (BS 4343)
C3.1 General
Where a radial final circuit feeds equipment the maximum demand of which, having allowed for diversity, is known or estimated not to exceed the rating of the overcurrent protective device and, in any event, does not exceed 20 A, the number of socket- outlets is unlimited.
C3.2 Circuit protection
The overcurrent protective device has a rating not exceeding 20 A.
C3.3 Conductor size
The size of conductor is determined from Appendix 4 of BS 7671 by applying the
Which may be of sod all use to you
C3
— —
the appliance is locally protected by a fuse to BS 1362, of a rating not exceeding 13 A, or the circuit is protected by a circuit-breaker of a rating not exceeding 16 A.
Radial final circuits using 16 A socket-outlets complying with BS EN 60309-2 (BS 4343)
C3.1 General
Where a radial final circuit feeds equipment the maximum demand of which, having allowed for diversity, is known or estimated not to exceed the rating of the overcurrent protective device and, in any event, does not exceed 20 A, the number of socket- outlets is unlimited.
C3.2 Circuit protection
The overcurrent protective device has a rating not exceeding 20 A.
C3.3 Conductor size
The size of conductor is determined from Appendix 4 of BS 7671 by applying the
Which may be of sod all use to you
What's the load? if load is less than 16a there is no issue in my opinion. You could wire you house socket circuit in 16mm and have it on a 80A mcb, would that mean all the sockets would suddenly melt? not sure but I think double sockets are rated at 20A anyway, yet we have them on 32A mcb all the time.
but 13a sockets have fused plugs... 60309's are unfused...
Good point Andy, but I think that's more to do with cable size supplying the appliance, it allows a minimised cable to be used - you seen what they wire kettles in these days? it's tiny stuff.
there's a discusion on here somewhere about using 1mm cable to shop lights from a 2.5mm wired cicruit on a 16 / 20A MCB, which is a similar situation. Cable to lights is effectively undersized, but fault current due to load is unlikely to overload cable ergo it is acceptable is the short version of a technical discussion statig how this is compliant. think the document was written by 'Click' who make those plug-in type lighting connectors for commercial lighting.
there's a discusion on here somewhere about using 1mm cable to shop lights from a 2.5mm wired cicruit on a 16 / 20A MCB, which is a similar situation. Cable to lights is effectively undersized, but fault current due to load is unlikely to overload cable ergo it is acceptable is the short version of a technical discussion statig how this is compliant. think the document was written by 'Click' who make those plug-in type lighting connectors for commercial lighting.
It is protection of the socket etc. I am thinking about, the cable is fine protected by the MCB.
Does the socket need protecting?...
Should it be protected, bearing in mind it is 16A rated, and the MCB is 20A rated...
13A sockets etc. are protected by the plug fuses.
Yes we have 13A sockets on a 32A ring, but, that is a "special" reg.
The socket is for "general use" thus no control over the load.
Hence the quandry.
It's not an EICR I've done, I have one by a good contractor in front of me & I have to make some recommendations on other stuff, using the EICR for reference, and I saw this, I felt the need to comment and say that it was not OK, then I had second thoughts and could not decide!
Does the socket need protecting?...
Should it be protected, bearing in mind it is 16A rated, and the MCB is 20A rated...
13A sockets etc. are protected by the plug fuses.
Yes we have 13A sockets on a 32A ring, but, that is a "special" reg.
The socket is for "general use" thus no control over the load.
Hence the quandry.
It's not an EICR I've done, I have one by a good contractor in front of me & I have to make some recommendations on other stuff, using the EICR for reference, and I saw this, I felt the need to comment and say that it was not OK, then I had second thoughts and could not decide!
depends on circumstances for what i would fit, but 7671 does state a 16a socket can be on a 20a circuit, so you cant give a code for something that is compliant
But irrespective of the OCPD size, a 16A socket should not have a load greater than 16A connected to it
As I said Andy, I'm not coding it, it's not my EICR.
It just "feels" wrong.
Andy, can you give a reg. no. that says you can connect a 16A 60309 to a 20A cct, as I have just searched 7671 for 60309 and could not find a reference to it being allowed on a 20A MCB specifically.
Even a reg. no. that precludes it.
It just "feels" wrong.
Andy, can you give a reg. no. that says you can connect a 16A 60309 to a 20A cct, as I have just searched 7671 for 60309 and could not find a reference to it being allowed on a 20A MCB specifically.
Even a reg. no. that precludes it.
I'm with Noz on this, the actual load through the pins should not exceed 16a, the cables supplying socket if 'ringed' will be jammed together in same terminals, so not conducting through the pins, if you see what I mean. Haven't got regs book to hand , but check out section(s) on sizing cables by CPC ability to handle likely fault currents
Hi Paul, i agree....
Have not got a reg book here, but all accessories etc have to be suitable for their purpose, surroundings etc. Now, how do you design a circuit?? You decide on the max load, then you decide on the OCPD required for this load, then you select a cable based on derating factors [insulation and all that] and volt drop and what R1+ R2 you require depending on Zs at the DB.
So, why would you select a 20A MCB if your circuit was designed for 16A.... It has to be, it feeds a single 16A socket. So, one of them has to be wrong, either the wrong socket, or the wrong OCPD.
Could it be in a misguided attempt to cure "nuisance tripping" instead of having a "C" curve MCB or whatever?? Is Zs at the furthest point of the circuit low enough for the OCPD selected??? If it is not, i would code the OCPD, if it is, [and the cable is suitable] i would code the socket.....
john...
Have not got a reg book here, but all accessories etc have to be suitable for their purpose, surroundings etc. Now, how do you design a circuit?? You decide on the max load, then you decide on the OCPD required for this load, then you select a cable based on derating factors [insulation and all that] and volt drop and what R1+ R2 you require depending on Zs at the DB.
So, why would you select a 20A MCB if your circuit was designed for 16A.... It has to be, it feeds a single 16A socket. So, one of them has to be wrong, either the wrong socket, or the wrong OCPD.
Could it be in a misguided attempt to cure "nuisance tripping" instead of having a "C" curve MCB or whatever?? Is Zs at the furthest point of the circuit low enough for the OCPD selected??? If it is not, i would code the OCPD, if it is, [and the cable is suitable] i would code the socket.....
john...
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All I can think is a nuisance start up tripping issue due to inrush current, and someone changed it to a 20A to "solve" that issue rather than trying a 16A type C for instance.
Mind the construction of most 60309's is such that I;ll bet they get a lot less bothered running at 20A than the average 13A socket does at 13A
Mind the construction of most 60309's is such that I;ll bet they get a lot less bothered running at 20A than the average 13A socket does at 13A
It is a B20, yes, so it could have been changed.
It just sits wrong to have a B20 on a 16A socket, if it is tripping it should be a C or D16, the EFLI measured by the contractor in 2012 was 0.4 Ohms.
Can't be bothered to look it up in 7671 etc., I have an NICEIC cert book here and they have a list on the inside of the front cover, right, wrong, not sure, but, even though it is NICEIC data you would hope it is right!
B16-2.3, C16-1.15, D16-0.58.
B20-1.84, C20-0.92, D30-0.46
So with a D16 @ 0.4 it is within the 0.58 required, so would be OK on a D16, which I bet would trip after a B20 on inrush and stuff.
I should check the curves on the two, but I can't be bothered!
Anyway, a C or D16 would be fine on EFLI.
It just sits wrong to have a B20 on a 16A socket, if it is tripping it should be a C or D16, the EFLI measured by the contractor in 2012 was 0.4 Ohms.
Can't be bothered to look it up in 7671 etc., I have an NICEIC cert book here and they have a list on the inside of the front cover, right, wrong, not sure, but, even though it is NICEIC data you would hope it is right!
B16-2.3, C16-1.15, D16-0.58.
B20-1.84, C20-0.92, D30-0.46
So with a D16 @ 0.4 it is within the 0.58 required, so would be OK on a D16, which I bet would trip after a B20 on inrush and stuff.
I should check the curves on the two, but I can't be bothered!
Anyway, a C or D16 would be fine on EFLI.
dont have regs here to look for it. apart from some at my own place that are on a 20a, i dont think ive ever fitted one elsewhere on a 20a, always been 16a
my reasoning is simple: unlikely to be overloaded, and there is more than 1 socket per circuit, and more than 1 may be in use at any time. most places will only use 1 socket per appliance, i.e welder etc. very few use splitters, so for most places, overloading is also unlikely
and as PD says, a 16a will happily take more than 16a without melting and burning a hole through the centre of the earth like what would happen if you took a 13a plug o 13a
my reasoning is simple: unlikely to be overloaded, and there is more than 1 socket per circuit, and more than 1 may be in use at any time. most places will only use 1 socket per appliance, i.e welder etc. very few use splitters, so for most places, overloading is also unlikely
and as PD says, a 16a will happily take more than 16a without melting and burning a hole through the centre of the earth like what would happen if you took a 13a plug o 13a
TBH I can't see anything massively wrong with having several 16A sockets on a 32A radial.... the over riding factor is that you shouldn't have a load greater than 16A connected via a 16A Plug/socket arrangement
If its only one socket - then, technically, there is no reason why the OCPD should be >16A ; as that is the technical maximum loading of the circuit.
However; I can`t find anything to preclude it, either.......
There is also the argument that, anything with a 16A commando plug on shouldn`t have a load >16A anyway - which brings you back to the socket circuit argument.........
I don`t like it; but I don`t think I`d pick it up; unless you were looking for the extra straw on the camel`s back, to decry the contractor who did the EICR.
FWIW
However; I can`t find anything to preclude it, either.......
There is also the argument that, anything with a 16A commando plug on shouldn`t have a load >16A anyway - which brings you back to the socket circuit argument.........
I don`t like it; but I don`t think I`d pick it up; unless you were looking for the extra straw on the camel`s back, to decry the contractor who did the EICR.
FWIW
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