I.T room

[dobo99]

Hi all

Got job this week to install power for about 60 pc`s in two rooms a school and was wondering bout the best way.

Was thinking of 2 rings wired in 2.5mm or 2 rings wired in 4mm or maybe 4x 4mm radials a room with seperate cpc (but unsure on size)

Will be using dado trunking to run it all in so space isnt a problem, just wanted idea`s from others who have done it before.

Also wondering about RCD protection as sockets will be dedicated to pc`s and a keyswitch will be used to isolate each room using contactor

thanks

 

[Zeespark]

Seperate ring for each room, 4mm2.

AndyGuinness

 

[Evans Electric]

I'd forget the RCD if I was doing it TBH. As for circuits , I think we have to say 1 amp for each PC and 1 amp for each screen and I'd guess they could all be on together with a class full of kids , so I'll leave you with the maths.

Deke

 

[dobo99]

thanks guys

would you bother running a seperate earth wire as well?

 

[Lee321]

don't understand how you have got the job if you haven't the competence to design it?

 

[Lee321]

Seperate ring for each room, 4mm2. AndyGuinness

is 4mm a stab at it headbang

 

[revjames]

Someones narky tonight........

 

[Lee321]

also concider startup currents. using a contactor to bring a whole bank of pc's on in 1 fowl swoop.

 

[Lee321]

Someones narky tonight........

kids educations at stake m8.

tripping mcb's just won't be cool will it

 

[dobo99]

don't understand how you have got the job if you haven't the competence to design it?

its a school we do lots of work for and they are now converting 2 old changing rooms to I.T suites

never done one before and have heard conflicting ways to do it from different places

 

[Andy™]

have a look through 543.7

 

[septiclecky]

Hi all Got job this week to install power for about 60 pc`s in two rooms a school and was wondering bout the best way.

Was thinking of 2 rings wired in 2.5mm or 2 rings wired in 4mm or maybe 4x 4mm radials a room with seperate cpc (but unsure on size)

Will be using dado trunking to run it all in so space isnt a problem, just wanted idea`s from others who have done it before.

Also wondering about RCD protection as sockets will be dedicated to pc`s and a keyswitch will be used to isolate each room using contactor

thanks

You have said 3 things there that if you put 60 PCs on 2 circuits with RCD protection, you would not keep the RCD from tripping as I think you have forgotten or you didn't know that the PSU on the PC has leakage due to the filter circuit in the PSU.

Therefore you should be looking at 10 PCs per circuit as you may have approx 2.5mA leakage per PC by the time you take the base unit and monitor into account.

 

[Lillpete]

You have said 3 things there that if you put 60 PCs on 2 circuits with RCD protection, you would not keep the RCD from tripping as I think you have forgotten or you didn't know that the PSU on the PC has leakage due to the filter circuit in the PSU. Therefore you should be looking at 10 PCs per circuit as you may have approx 2.5mA leakage per PC by the time you take the base unit and monitor into account.

what he said

 

[spinlondon]

You have said 3 things there that if you put 60 PCs on 2 circuits with RCD protection, you would not keep the RCD from tripping as I think you have forgotten or you didn't know that the PSU on the PC has leakage due to the filter circuit in the PSU. Therefore you should be looking at 10 PCs per circuit as you may have approx 2.5mA leakage per PC by the time you take the base unit and monitor into account.

Would that be only if RCD protection was being used?

 

[SteveH37]

would be good to see a layout of the room to decide on setup before designing circuit arrangements, perhaps the use of an additional Submain DB locally with a number of radials would be best course of action.

 

[septiclecky]

Would that be only if RCD protection was being used?

Well if there is no RCD fitted how could it trip

 

[Lee321]

rcd requirement can easily be designed out

 

[spinlondon]

Well if there is no RCD fitted how could it trip

Sorry, but your post wasn't very clear.

Just trying to work out if your saying 10 PCs per circuit with RCD protection, or just 10 PCs per circuit in general.

 

[septiclecky]

Sorry, but your post wasn't very clear.Just trying to work out if your saying 10 PCs per circuit with RCD protection, or just 10 PCs per circuit in general.

As I had said earleir about RCDs and leakage I thought common sense would have prevailed and releised when 2.5 mA X 10 = 25 mA on a 30ma RCDheadbang

 

[kme]

Don`t forget the (possible) requirement for "high protective conductor current" labelling.......

KME