As I understand it, all sockets need to be RCD protected now, but unless there are buried cables, light and storage heaters don't.
So in an (office) installation where the wiring is in metal trunking & conduit, only socket circuits would need RCDs ?
Is there any reason that the RCD for a socket circuit cannot be external to the DB ? In our offices, we have "old" Bill DBs, and a DIN rain box mounted above them with contactor(s) for the night storage heating. I'm thinking that a quick way to upgrade to current standards would be to throw an RCD or two in this box and move the tails.
This is the only photo I have at the moment. Ignore the soot marks - the contactor has been replaced at some time in the past !
I figure the answer changes for those units where the switch drops are buried in plaster with galv capping.
There are several reasons for me asking. Partly it's to check that I'm understanding the regs properly.
Partly it's having been told that "they must be replaced as obsolete".
And partly, as part of some shifting around in our own unit (all metal trunking & conduit) I expect some wiring changes will be needed and if they use the same sparky as in the line above, I expect he'll be insisting that everything be RCD protected - I'm not keen on the server room sharing an RCD with circuits that could make it trip.
Interestingly, while helping out the centre manager*, in conversation it turns out that they asked the aformentioned sparky to leave the breakers from the boards he's taken out to use as spares. Apparently they "must have ended up on the van by mistake" I said "yeah right", apparently I wasn't the only one to have said that.
* They have a unit where part of it was once a meeting room and is on the landlords supply, and part was a self contain unit with it's own supply. Part of a wall was removed a long time ago so it's one unit now. She was asking me how big a job it was to sort it out, and whether it needed a new supply - on the basis that she knows "very little" about electrics and wanted a bit of knowledge so as to be able to tell if someone was "talking up the job".
I was able to confirm that there are two supplies (what appear to be original circuits in the old meeting room part stayed live when the main switch was off in the other part), but it's also clear that there's been "additions and changes". I did say that it needs a sparky who is reasonably good at working out what's been done and what goes where, but it shouldn't be a big job to sort out. But once anyone starts working on circuits, any circuits they work on will need to meet current standards - hence the need to add RCD to some circuits.
So in an (office) installation where the wiring is in metal trunking & conduit, only socket circuits would need RCDs ?
Is there any reason that the RCD for a socket circuit cannot be external to the DB ? In our offices, we have "old" Bill DBs, and a DIN rain box mounted above them with contactor(s) for the night storage heating. I'm thinking that a quick way to upgrade to current standards would be to throw an RCD or two in this box and move the tails.
This is the only photo I have at the moment. Ignore the soot marks - the contactor has been replaced at some time in the past !
I figure the answer changes for those units where the switch drops are buried in plaster with galv capping.
There are several reasons for me asking. Partly it's to check that I'm understanding the regs properly.
Partly it's having been told that "they must be replaced as obsolete".
And partly, as part of some shifting around in our own unit (all metal trunking & conduit) I expect some wiring changes will be needed and if they use the same sparky as in the line above, I expect he'll be insisting that everything be RCD protected - I'm not keen on the server room sharing an RCD with circuits that could make it trip.
Interestingly, while helping out the centre manager*, in conversation it turns out that they asked the aformentioned sparky to leave the breakers from the boards he's taken out to use as spares. Apparently they "must have ended up on the van by mistake" I said "yeah right", apparently I wasn't the only one to have said that.
* They have a unit where part of it was once a meeting room and is on the landlords supply, and part was a self contain unit with it's own supply. Part of a wall was removed a long time ago so it's one unit now. She was asking me how big a job it was to sort it out, and whether it needed a new supply - on the basis that she knows "very little" about electrics and wanted a bit of knowledge so as to be able to tell if someone was "talking up the job".
I was able to confirm that there are two supplies (what appear to be original circuits in the old meeting room part stayed live when the main switch was off in the other part), but it's also clear that there's been "additions and changes". I did say that it needs a sparky who is reasonably good at working out what's been done and what goes where, but it shouldn't be a big job to sort out. But once anyone starts working on circuits, any circuits they work on will need to meet current standards - hence the need to add RCD to some circuits.