Electrak - no RCBOs

[IAmSparkytus!]

We have a customer in a large office block with all power in the building fed from an Electrak plug in busbar system. Lots of desks, lots of computers.

Noticed none of the track is on an RCD/RCBO but they’re wanting some of the floor boxes relocated.

Would this fall under the remit of needing to upgrade from an MCB? Guessing not as we wouldn’t actually be connected or disconnecting anything other than the plug feeding each floor box if even required (might be enough length on them to reach new position).

Would recommend upgrading to RCBOs anyways but where do I stand on needing 30mA protection when there are so many computers plugged into each likely having a high level of leakage?

 

[James]

nightmare, was asked to investigate random tripping of office sockets in a large office as you describe.
turned out, someone had been in and done an EICR, later to "fix" the C3 about rcd protection for sockets (2nd floor office) they had changed all the breakers for rcbo's
cumulative leakage from pc's printers etc was the issue.

explained the problem and quoted to split the socket runs in half and feed from the middle of each run to 2 separate rcbo's
didnt hear a peep from them, i expect they gave the in house maintenance bloke a round of **** and told him to put it back how it was!!

 

[Lou7]

You could put rcd sockets in the floor boxes.

 

[Mikegh]

You could put rcd sockets in the floor boxes.

You'd assume there would be too much standing leakage and too much potential disruption otherwise

 

[MDJ]

We have a customer in a large office block with all power in the building fed from an Electrak plug in busbar system. Lots of desks, lots of computers.

Noticed none of the track is on an RCD/RCBO but they’re wanting some of the floor boxes relocated.

Would this fall under the remit of needing to upgrade from an MCB? Guessing not as we wouldn’t actually be connected or disconnecting anything other than the plug feeding each floor box if even required (might be enough length on them to reach new position).

Would recommend upgrading to RCBOs anyways but where do I stand on needing 30mA protection when there are so many computers plugged into each likely having a high level of leakage?

I have seen this loads of times, I work in an office environment, what we do is make sure the individual sockets on the desks have RCD protection at the socket and then nuisance tripping will not happen, of course the customer will need to pay for the sockets to be changed and if not you could just say the desks do not conform to modern regs but did confirm at time of fitting, this is a can of worms, a crown of thorns.

 

[Mikegh]

There used to be a guide of 3.5mA per workstation, so that allowed for 4 to keep under 1/2 I∆N, dunno is that accurate these days

Is this the SP 63A busbar trunking, there'd be a heap of equipment on that

Even if it didn't trip, you're still introducing a potential nuisance for when it does knock off the lot by front loading an RCD

 

[pc1966]

There used to be a guide of 3.5mA per workstation, so that allowed for 4 to keep under 1/2 I∆N, dunno is that accurate these days

I recently measured a couple of items due to an odd RCBO tripping problem but found the modern desktop style PC PSU was only leaking about 0.5mA, the other stuff (monitor, network switch, both class II or at most FE) were more or less 0.1mA.

 

[Mikegh]

Leaves the potential nuisance of knocking off a raft of equipment unnecessarily