No, I was also referring to diversity relating to just the circuit supplying the heater and shower.
Kind Regards, John
Putting bathroom heater on shower circuit?
- Thread starter propertydev83
- Start date
Kind Regards, John
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Having the heater switched off for the relatively short period of time a shower takes ought not to be a major inconvenience.
So, you might want to consider fitting a changeover switch, shower or heater but not both.
So, you might want to consider fitting a changeover switch, shower or heater but not both.
Wouldn't the 32A MCB be very near tripping in the 20 minutes?
I don't think it would be good for it in the long term.
If it were a 32A MCB that would probably be the case. However, as I understand it, it's currently 40A, with suggestions that it may be upgraded to 45A.
Kind Regards, John
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Oh. Of course - silly me. Sorry
I wasn't sure if diversity would apply in this instance, and as I understand it is not always an exact science, sometimes relying on judgement calls.
I think my dad would be happiest knowing it is both safe and compliant first and foremost, followed by what would be easiest to install. Cost is not so much an issue.
What is the easiest option for adding RCD protection, if it were to be spurred off the sockets circuit?
I think my dad would be happiest knowing it is both safe and compliant first and foremost, followed by what would be easiest to install. Cost is not so much an issue.
What is the easiest option for adding RCD protection, if it were to be spurred off the sockets circuit?
Indeed - which is why I 'asked the question' and invited discussion, rather than 'asserting' anything.
A 50A MCB or RCBO would obviously make a 48A load both safe and compliant. Whether or not a 40A or 45A device would be compliant depends upon the above judgement in relation to diversity. However, even without diversity, I personally don't think there would be any significant safety issue, even if it were technically non-compliant. A 45A device should never trip - it is required to carry 50.85A (45A x 1.13) indefinitely, and 65.25A (45A x 1.45) for up to one hour. Even a 40A one is required to carry 45.2A indefinitely and 58A for up to one hour - so, again, would almost certainly never trip. However, it is technically wrong, and maybe would shorten the life of the MCB/RCBO, to subject a device to a current in excess of its rating - but, of course, one would not really be doing that if one believed that application of diversity was valid.
If I understand the question correctly, the simplest solution would be to use an RCD FCU.
Kind Regards, John
I suppose if using 230V for the maths then 11500W/230V=50A, so a 45A breaker wouldn't trip. The issue here is still with the wiring. It is 10mm cable. The shower circuit was added to the original part of the house when they had an extension built in the 90s and other new wiring and the consumer unit were added. It is an old uninsulated house, with the exception of some very thin loft insulation.
Upgrading the breaker to 45A or 50A would be the easiest option if he wants to keep the loft sockets, if it can be ascertained that the 10mm cable would not overheat. Then run the heater from the shower radial in the loft.
If it would not be possible, then the less easy option for keeping the loft sockets would be to locate where the spur is taken from on the 1st floor, and change it to an FCU spur. Then run the heater from the sockets spur in the loft, incorporating a RCD FCU.
Or if he loses the sockets in the loft, then as above but without changing the spur to an FCU spur on the first floor. Easiest overall, but sacrificing those loft sockets.
Time for a phone call.
Upgrading the breaker to 45A or 50A would be the easiest option if he wants to keep the loft sockets, if it can be ascertained that the 10mm cable would not overheat. Then run the heater from the shower radial in the loft.
If it would not be possible, then the less easy option for keeping the loft sockets would be to locate where the spur is taken from on the 1st floor, and change it to an FCU spur. Then run the heater from the sockets spur in the loft, incorporating a RCD FCU.
Or if he loses the sockets in the loft, then as above but without changing the spur to an FCU spur on the first floor. Easiest overall, but sacrificing those loft sockets.
Time for a phone call.
It's very probable that those powers (hence the 11,500W) relate to 240V (they do that seemingly to make their products sound more powerful), but if, as is the convention, one works out the current at 230V, that would equate to a current of only about 45.9A (and a 'true' power, at 230V, of about 10,562W).
As I've implied, I do not personally think that the cable would significantly overheat, even if the installation method of the cable is less than ideal. However, opinions may vary, particularly as regards what is strictly 'compliant'.
You previously implied that there is just one socket in the loft (which is actually all that would be allowed on an unfused spur), but you now talk of 'sockets'. You don't necessarily need to find the source of the spur. If there is just one loft socket, you could just put an RCD FCU upstream ('in front') of it (in the loft, maybe close to the socket). If there are more than two sockets, then there really ought to be an FCU upstream of them, anyway, so you could add that (upstream of the first socket, in the loft). Either way, of course, you would be limited by the FCU to a total of 13A for the loft socket(s) plus the new heater.
Kind Regards, John
Sorry I'm on the phone at the moment but there is one socket outlet in the loft (the plural reference was because it is a double socket). My bad.
If not, then spurring off a socket circuit as suggested may be possible if that is compliant? There is a socketIf not, then spurring off a socket circuit as ? in the loft but unfortunately it is already on a spur...)[/QUOTE Just change it to a twin RCD socket and plug the heater into that.
easy !
DS[/QUOTE]
easy !DS[/QUOTE]
OK, so if 13A were enough for the heater plus that double socket (really depends on what that socket is likely to be used for), then you could just put an RCD FCU just upstream of the socket in the loft. However, I personally think that you 'Plan A' (with a 45A or 50A RCBO) would be OK - but, as I've said, others may not be so keen!
Kind Regards, John
That would be fine if he were happy to plug the heater directly (or via an extension lead) into a socket in the loft or ('nasty') run some 'fixed wiring' from a plug plugged into the socket to a socket for the heater - but I suspect (may be wrong!) that none of those options would be convenient/acceptable.
As I said, the alternative (similar to your suggestion) would be to keep the 'ordinary' socket in the loft, put an RCD FCU immediately in front of it and then run fixed wiring from that socket to a single socket for the heater. The only downside would be the limitation to a total load of 13A.
Kind Regards, John
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