Are office sockets allowed not to be rcd protected

[sl1210]

went to an office this week where there are 2 rcbo's nuisance tripping every now and then. apparently one does the floor sockets in the office and one does the wall sockets in the office, now as the office was full of staff working on their computers i could only go by what one member of staff told me as i couldn't turn mcb's on and off. but this is what they are labelled as also and they say ring have two cables going into them and are only 20a c type breakers.

so to eliminate the possibility of a faulty appliance, today i did a full pat test on everything in the office, and removed 1 surge protected extension lead, everything seemed to pass. they say it hasn't tripped since last monday, but more than likely it will trip again.

now the majority of the floor sockets are the computers and monitors, so high earth leakage is definitely a possibility although they havent had any problems the whole year they have been there, but they say they have added more computers.

do these sockets need to be rcd protected, or can they be changed back to an ordinary mcb???

see the problem i have at the moment without being to test is whether its an overload/short circuit or an rcd fault.

also they have just had mice problems sorted out, maybe a coincidence???

 

[sl1210]

just found this in the regs

The designer’s decision process
In a commercial situation, forexample, such as an officeenvironment, where theemployer states in companypolicy that employees must notbring in appliances, such asphone chargers and radiosand that only the company’stested appliances can be used,then RCD protection forsocket-outlets can be omitted.

 

[KAS1]

Are the sockets used by ordinary persons or instructed persons?

 

[sl1210]

at the moment just ordinary staff. to be honest i don't know if i feel comfortable removing the rcbo's

 

[iconnect]

Change the socket for computer sockets with earth pin turned on the side then remove rcbo's that way only computers can be plugged in on that circuit as intended

 

[SirKit Breaker]

You probably aren't getting nuisance tripping, but it is a nuisance. It is probably the amount of earth leakage current which is causing the tripping. IT stuff works on earth leakage, once the combined leakage equals 30mA, the RCD will trip.

Cheers...........Howard

 

[HandySparks]

see the problem i have at the moment without being to test is whether its an overload/short circuit or an rcd fault.

Get yourself a good quality clamp meter that is sensitive enough to do earth leakage measurements as well as high current. Then you'll know.

Also, arrange to visit out of hours and test the RCBOs properly.

 

[telectrix]

take the RCBO that feeds the computers out.fdit MCB. instruct office manager that sockets are for use of IT only. as post #2.

 

[snowhead]

P.A.Test,,,,tick.

I.R. test on the circuits, don't see a tick?

 

[sl1210]

well yeah the next point of call if the problem persists is to go in on a dreaded saturday and ir the circuits. and test the ring continuity and see why they are on 20a rcbo's if they are complete rings.

see the wall sockets (2nd rcbo) seem to have electric heaters with plug tops plugged into them. so i'm sure if all 4 are on the same circuit and on at the same time than overload is a very high possibility. but they have always been like this, and she says they trip overnight sometimes when everything is off except computers. although i guess they wouldn't of had all the heaters on in the summer.

see its an old merlin board and these 2 suspect 20a c type rcbo's are schneider and look like they have been put in recently, although they say noone has done electrical work in the whole year they have been there....

 

[Guest55]

You probably aren't getting nuisance tripping, but it is a nuisance. It is probably the amount of earth leakage current which is causing the tripping. IT stuff works on earth leakage, once the combined leakage equals 30mA, the RCD will trip.

Cheers...........Howard

a rcd can function & test correctly but still begin to unlatch as early as 17ma.
and your average desktop office computer has earth leakage around 3-4ma per work station.
so we can deduce that even if everything is working normally , 5-6 computers will trip most rcbo's.
if the cables are surface installed then i'd be getting rid of the rcbo's and get the general manager to issue written instruction that no personal or portable items be used in the non rcd protected computer sockets , and have those sockets labbelled as such.

 

[Silly Sausage]

get the general manager to issue written instruction that no personal or portable items be used in the non rcd protected computer sockets.

See post 5!

 

[Guest55]

See post 5!

see post #13

**** off.
;-)

 

[sl1210]

if i do go back then i will have to try and source 2 x merlin gerin/schneider 32a mcbs and 2x 20a mcbs either way to replace the rcbo's. As at the moment they are 20 amps but if the circuits are complete rings then it would be best to upgrade them to 32a to rule out any possible overloads in the future.

 

[ste77]

if i do go back then i will have to try and source 2 x merlin gerin/schneider 32a mcbs and 2x 20a mcbs either way to replace the rcbo's. As at the moment they are 20 amps but if the circuits are complete rings then it would be best to upgrade them to 32a to rule out any possible overloads in the future.

I have 2 spare merlin gerin 32A mcbs that i took out last week to replace for rcbos, you can have them if it helps, may have some 20s not sure til i look in the van.