How many computers to 1 30ma rcd

[simpson93]

Hello all, just wondering in an office with lots of it equipment how many computers would you put to one 30ma circuit?

 

[Guest77]

None I would remove the RCD and use a MCB, however if an engineer told me I had to keep the silly thing I would have no more than 4 max on it, if a printer on the circuit then 3 and not 4.

 

[Deleted member 72666]

None, zero, nilch!

 

[bigdavs83]

If they are insistent on rcd protection then fit rcd sockets rather than an rcd or rcbo at the db. The earth leakage from 4,5,6 computers depending on efficiency and age can trip them very easily

 

[Knobhead]

^^^ I'm with those two

 

[trev]

Once had to fit a dedicated RFC for computers in a school. Told the guy who designed it that he was being silly putting it on an RCD and was overruled. What the hell did I know, Just a bloody sparky were pretty much his exact words.
When the RCD wouldn't hold I didn't laugh (much)

 

[Sintra]

If you MUST use an RCBO or RCD use at a minimum a type A or preferably a type B.

 

[simpson93]

Thanks all, guess I'll leave off rcd or try rcbos

 

[Guest77]

Thanks all, guess I'll leave off rcd or try rcbos

???say again??

 

[Deleted member 72666]

???say again??

You're going to need an inhaler at this rate if you're not careful Mike!

 

[bigdavs83]

Rcbo is an rcd just with built in overload protection so basically an mcb and an rcd rolled into one so it will be rated at a certain mA as well.

 

[Simonslimline]

Rcbo is an rcd just with built in overload protection so basically an mcb and an rcd rolled into one so it will be rated at a certain mA as well.

Maybe he means a few on each RCBO rather than the lot protected by a single RCD.

 

[bigdavs83]

Maybe he means a few on each RCBO rather than the lot protected by a single RCD.

Ha aye maybe.

 

[simpson93]

Aye meant as above

 

[Engineer54]

If they are insistent on rcd protection then fit rcd sockets rather than an rcd or rcbo at the db. The earth leakage from 4,5,6 computers depending on efficiency and age can trip them very easily

And if the final circuits didn't meet with the 50mm buried depth rule?? If were talking about a shed load of computer work stations over several circuits, fitting RCD sockets is going to bump the cost of the installation way up there. Personally i use the rule of 5 computer orientated loads eg, PC, Printer, Scanner etc (or 3 X double sockets).. per 30mA protected circuit. Can't say i've ever had any nuisance tripping problems to date....

 

[davesparks]

And if the final circuits didn't meet with the 50mm buried depth rule?? ....

Then use steel conduit for the drops.

These days a room full of computers is almost certainly going to be wired in a surface trunking or underfloor trunking of some description anyway.

 

[cliffed]

Instructed to put computer sockets on rcd,32amp,30ma,we usually put 7 twins on ring,using 2 terminal earth's connections,no problems whatsoever .Its a college & installed this method in all IT rooms ,cheers

 

[Engineer54]

Instructed to put computer sockets on rcd,32amp,30ma,we usually put 7 twins on ring,using 2 terminal earth's connections,no problems whatsoever .Its a college & installed this method in all IT rooms ,cheers

I assume you mean 32A RCBO's and not one 30mA RCD looking after several ring circuits feeding IT equipments?? We use 16A radial circuits for computer workstations with a ringed or if you like an additional CPC....

All such IT installations should be wired using the high integrity earthing arrangements.

 

[Pete999]

^^^ I'm with those two

I'm with those that he's with and him of course

 

[Badged01]

I'm with those that he's with and him of course

I'll second that. Im with anyone, who's with anyone, that knows someone who might know something ....... I like to shift blame quick (Successful management rule #1) :angel_smile: