Replacing a 7kw shower with 8.5kw- minimum cable size
- Thread starter phil001
- Start date
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Having seen various leaks etc within showers I think it is foolhardy to say the least to have a shower without an RCD. For peace of mind you should make sure you have an RCD fitted.
You have no business having a home and buying a new shower without considering the benefits of an RCD protecting your shower.
Also, you need to be sure of the cable size. Newer cable may have the size stamped on it. A photograph will help us identify it. 30 years ago it was fairly common to see showers wired in only 4.0 mm2, so it does need checking.
The instructions state:
5.1 A 30mA residual current device (RCD) must
be installed in all UK electric and pumped
shower circuits.
This is not strictly true.
It is true for new installations but the OP's circuit does not have an RCD and is, because of when it was installed, perfectly acceptable and does not have to be brought up to current requirements.
The Building Regulations state that work must be notified if:
(6A) ... the work consists of—
(c) any addition or alteration to existing circuits in a special location.
Therefore if an RCD were to be fitted it is notifiable but a replacement is not.
The instructions also state that:
6 A 45 amp double pole isolating switch with
a minimum contact gap of 3 mm in both
poles must be incorporated in the circuit.
So, are you saying that if the OP should happen to have a 50A switch then this must be replaced?
Would this also require notification?
Whilst an RCD may be desirable and advisable it has nothing to do with the workings of the shower and therefore the instructions must relate to the circuit.
Does the circuit have to be altered for a simple replacement?
5.1 A 30mA residual current device (RCD) must
be installed in all UK electric and pumped
shower circuits.
This is not strictly true.
It is true for new installations but the OP's circuit does not have an RCD and is, because of when it was installed, perfectly acceptable and does not have to be brought up to current requirements.
The Building Regulations state that work must be notified if:
(6A) ... the work consists of—
(c) any addition or alteration to existing circuits in a special location.
Therefore if an RCD were to be fitted it is notifiable but a replacement is not.
The instructions also state that:
6 A 45 amp double pole isolating switch with
a minimum contact gap of 3 mm in both
poles must be incorporated in the circuit.
So, are you saying that if the OP should happen to have a 50A switch then this must be replaced?
Would this also require notification?
Whilst an RCD may be desirable and advisable it has nothing to do with the workings of the shower and therefore the instructions must relate to the circuit.
Does the circuit have to be altered for a simple replacement?
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4mm² would be adequate in this situation as long as it runs through no thermal insulation nor conduit.
If the instructions state the new shower must be protected by an RCD, I can't see how you can ignore that.
We talk about like-for-like replacements, but if we imagine the old shower didn't stipulate an RCD, and the replacement is, let's say, a different model and more importantly demands an RCD - then it needs an RCD.
I would never recommend anyone fitting a shower without an RCD anyway.
By a 45 amp isolating switch, though not actually written as such, I think we all know they mean 45 amp MINIMUM.
We could have a 13 amp plug top (yes, plug top) with a 5 amp fuse in it, but no none is going to call it a 5 amp plug (top).
We talk about like-for-like replacements, but if we imagine the old shower didn't stipulate an RCD, and the replacement is, let's say, a different model and more importantly demands an RCD - then it needs an RCD.
I would never recommend anyone fitting a shower without an RCD anyway.
By a 45 amp isolating switch, though not actually written as such, I think we all know they mean 45 amp MINIMUM.
We could have a 13 amp plug top (yes, plug top) with a 5 amp fuse in it, but no none is going to call it a 5 amp plug (top).
But that's the point, they don't.
It's the circuit.
Neither would I but he already has one.
But that's not what it says.
Ok, so the instructions state the circuit must be protected by an RCD. So you'd have to make sure the circuit IS protected by an RCD, wouldn't you?
It is implied twice that he doesn't have an RCD.
Despite the poor phrasing, we all know a 50 amp isolating switch is just as good/better than a 45 amp one.
I find it all a bit confusing. It's not totally clear to me as to whether these 'notes for guidance only' are just an attempt to summarise (as you say, not strictly correctly) the requirements of BS7671 and/or something which has to be treated as "MIs" (SHMBO - at least until next year). I presume you are assuming the former?
We've discussed that before, and it's a bit ambiguous. It's not clear (at least, to me) whether they are talking about 'parts of a circuit which themselves (the parts) are within a special location' OR 'any part of a circuit which serves a special location, even if the work involves a part of the circuit outside of the special location'. I find it hard to believe that the latter is the intention since, if that were the case, then, say, modification/extension of bedroom lighting would presumably be notifiable if the same lighting circuit supplied a bathroom.
See above - I personally find it hard to believe that the intent is that this would be notifiable if the switch were installed outside of the special location.
As above, it depends upon whether one regards the material quoted above as "MIs". If one does then, at least until next year, one is theoretically stuck with anything the MIs say, regardless of whether or not they have got anything to do with the workings of the shower. Of course, what will worry people, even next year is ....
Even for you and I, it would probably be at the least a hassle to try to argue with them that a breakdown had not resulted from the absence of an RCD or the fact that there was a 45A, rather than 40A, MCB - and I imagine that the average Joe Public would not even attempt to argue the point if a warranty claim was refused for such a reason.Triton Standard Guarantee said:
Kind Regards, John
See what I've just written to EFLI. It is not clear as to whether what is written in that document constitutes 'instructions' or whether (which is what it seems to say) it is a clumsy and inaccurate attempt to summarise the requirements of BS7671. Indeed, what is stated clearly is that the whole section (including the bit about RCD protection) is 'for guidance only' - so I don't think it can really be regarded as an 'instruction'.
Of course, that is all about 'bureaucracy' and doesn't alter the fact that I think we all are agreed that it is highly desirable and advisable for a shower to be RCD protected - if not only because of our intuitive gut feelings about the coming together of electricity, water and wet naked human bodies!
Kind Regards, John
How "crappy" is the old crappy one. ? If really crappy and repaired in a less than perfect way then that is even more reason to have an RCD fitted.
The RCD does more than protect the circuit, it limits the duration of electrical shock to one that is less likely to be fatal.
If you save money by not having an RCD fitted for the shower then put the money you saved into your funeral funds.
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