Air con units and it equipment on RCD?

[thomaspotato]

Hi ,

I usually do domestic work but i have an office job to price and i was wondering if the following items should be RCD protected, the reason i ask is for nuisance tripping.

Air con units 3ph and single
Sockets for the office computers
Comms/Patch panel

Thanks

 

[buzzlightyear]

Sockets for the office computers

Contractors need to be aware that equipment, typically refrigerators, freezers, IT equipment and controls, and luminaires are likely to cause inconvenience and disruption by unwanted RCD tripping. It is recommended that in order to minimise unwanted tripping, the sum total of standing leakage currents should not exceed 25% of the tripping current rating (I∆n) of the RCD protecting the circuit(s). Modern fluorescent fittings with electronic ballasts can have 1mA leakage current for every tube. IT equipment may have up to 3.5 mA leakage at each work station. It can therefore be seen that a single 30 mA RCD is only suitable for a few items of equipment. If too many items are connected, unwanted tripping is bound to occur and when a problem occurs it is likely to bounce back to the contractor.

 

[westward10]

Assuming this is a TN earthing system air con units, if the circuits are suitably installed would not require it. If it is a small comms cabinet, hard wire it. Socket outlets need to be arranged so as to prevent nuisance tripping of the rcd/rcbo.

 

[davesparks]

Hi ,

I usually do domestic work but i have an office job to price and i was wondering if the following items should be RCD protected, the reason i ask is for nuisance tripping.

Air con units 3ph and single
Sockets for the office computers
Comms/Patch panel

Thanks

The first thing to do is to look at the regulations to establish which circuits, points or locations require RCD protection.
The usual domestic approach of 'everything on an RCD' is not necessary or desirable outside of a domestic installation.

Generally in an office you will only need RCD protection for socket outlets. Lighting circuits, fixed equipment etc is unlikely to require RCD protection.