Nuts for RCDs!

[Deservices]

Now I am not getting involved in a argument, but it is down to interpretation. IT equipment will leak to earth therefore causing a RCD/RCBO to trip if to much is installed on one circuit. This is what the OP wanted to avoid. Now the sockets wont be used or constantly monitored by a skilled person. As to do that would be bloody expensive to employ effectively retail assistants.

The customer has not stated they dont want the sockets RCD protecting as again the OP has said he has done the design, install and testing.

So the only way I see it possible to do this would be too.

A. Work out earth leakage of each item of equipment
B. Install enough circuits so that none reach the limits of nuisance tripping
C. Install each circuit on a RCBO

He would also do the design based on what they wanted. But as he's not stated they didn't want RCD protection, I would also of fitted one if not been requested not to. but of told them possible trips and adjusted needed ie maybe run a few radials.

 

[Jimmy Boy]

I don't see any confusion, he has applied section 411.3.3, and used exceptions a, or b, under this reg, as long as the sockets are under the supervision or a skilled or instructed person ( IMHO this should be noted on the cert ) OR the socket outlets are labelled for use with a particular item of equipment he isn't in contravention of the regs, but I still await the OP's response to my earlier question why he thinks RCD protection only applies to domestic dwellings ?
ATB
J

 

[Deservices]

The term mobile is for a item that is moved while it is plugged in ie floor cleaner lawn mower not commuter monitor.

 

[Jimmy Boy]

TBH I think it is going a little off track, the question is, will those sockets be used or be LIKELY to be used by 'ordinary' persons ?..answer yes, then apply the regs RCD them, answer no, then use the exceptions in the regs, but, and here is the rub, I can foresee very very few office situations, where you can reasonably guarantee that no one other than those skilled or instructed persons will use those sockets, the cleaners come in a ten at night use the sockets, or some maintenance man, too many variables for my liking but as I say it's down to the signatory ! It's his head on the block if it goes pear shaped !
J

 

[Engineer54]

Far too much being read into this, ...exactly what are you expecting to go wrong, if and when the instructed person is out of the room/office?? He has stated the dedicated outlet for the cleaner has been RCD'd??

You simply can't cover every single possibility of usage of a circuit, that is out of any electricians control. As far as i can see there is nothing wrong with the OP's installation. ...And no he won't have his head on the block!!

 

[dagrat]

I agree with Engineer 54,I think that the regulation as it stands refers to installations that come under the control of a competent person, and therefore does not necessarily refers to persons using the computer.
One reason the RCD regulation is relaxed in these situations is because it is assumed (for example) that any drilling in these locations will only be undertaken by a skilled and competent person. So no probs

 

[oldtimer]

Good discussion guys and me thinks we are missing the point as we are all lead to believe that RCDs were introduced because an MPs daughter was sadly killed but me I am more cynical than this I think because RCDs became more economically viable the MPs daughter was used as a vehicle for interested parties ie the Scheme providers to strengthen their position within the industry and at the same time they get to ride on the back of improving safety . Also they thought via Part Pish they thought they could control the domestic environment but stayed well clear of trying to force it on the commercial and industrial sector. Remember the you cannot back date the regs but you put it in such a way that if you make changes then you need to apply them.

Now as for CEF being in the industrial and commercial class well yes but there is one problem their when you walk in they have a lot of lighting displays so in a sense they have to be RCD protected even although the majority of the people on the customer side are electricians they have to be treated as Joe Publics

 

[smu_diddly]

I don't think cef will have enough IT equipment to cause an rcd to trip, you would need like a huge office full of them to produce enough leakage to trip. If all other circuits are in conduit then fine leave the rcds off them but stick an rcbo on the sockets. I wouldn't take the risk.

 

[imago]

exactly what are you expecting to go wrong,

Well they used Proteus gear, so .........

 

[Engineer54]

Will someone please tell me what far out and away risks were talking about here. these sockets were talking about are in metal conduit containment, so no-ones going to be putting screws or pins through the wiring. Assuming that the ADS is well up to specifications, tell me what risks are we talking about on these IT/computer dedicated outlets....