back to the past

[devlin maguire]

Hi All
where in the 16th does it say that a rcd cannot be used as an incomer I know we dont and never have I need to point out to individual that this is and has always been the case I have been through part 3 is this how reg 314. is interpreted.This was an install back in 2000 to the 16th but has been altered dramatically in its exsitance and there is now T+E as mains supply through an RCD to the CU. I dont need to convince the owner just the guy who says it's ok as is
Mac

 

[roukel01]

I thought RCD's could be used as incomers, hence the reason you have RCD characteristics on an Electrical Installation Certificate.

 

[bugsy]

I think it was under safe isolation and disconnection i'll have to do some digging ( pm lenny )

 

[devlin maguire]

It was my understading that this was to be avoided as a single fault tates out everything

 

[pennywise]

Not if its a time delay one or the rating of the rcds down stream are of a lower rating surely.

 

[oldtimer]

I have seen a couple of boards that have the RCD doing 2 jobs 1 as safety breaker and 2 as main switch and they were sold in that condition so this tells me that this this was a bit of interpitation before the 17th came into play and has now been clarified.

 

[Guest123]

An RCD as a unit can be used as a main isolation device as it is suitable for isolation, emergency switching and functional switching (Table 53.2, Page 117 in ol' red).

The issue arises where discrimination is needed between one or more RCD's or minimising the inconvenience caused in the event of a fault by having only one RCD protecting all the circuits in an installation.


What scenario do you have there???

 

[Graeme Harrold]

Another thing to bear in mind is an RCD does not incorporate over current protection.....

 

[JT C]

It depends on what type of system you have. A TT system requires 100ma RCD protection to the entire installation due to the fact that the disconnection time can not be guaranteed. 30ma protection is split in order to prevent nuisance caused in event of fault in the 17th. The 16th just stated that consideration should be given to minimise nuisance tripping.

 

[devlin maguire]

The situation I have is a dual tarrif board installed in 2000 ish and the installation has been changed a lot it now has the supply conductors are now T+E of I reckon 10mm through a remote RCD100AMP/ 30ma then into a 60947-3 main earth is two yes two ? 6mm combined with the CPC of the T+E, I have they go ahead to upgrade but the company engioneer is a bit peeved as he did the alteration my position is in they event of a fault every thing goes I wanted to quote the reg covering this and i think Reg 314 backs me up
Mac