Coding for Sockets Following EICR

Question

Gents/Ladies, We have just had an EICR carried out on our premises (industrial) and the following Code C3 as been given for no RCD protection on sockets. I was under the impression that all single phase and three phase sockets up to 32amp were required to have RCD'S/RCBO'S or RCD sockets, unless a written Risk Assessment was issued. Is this correct?

AJJewsbury · Answer

The usual rule of thumb for lack of additional protection by 30mA RCD on domestic sockets is C3 for ones just serving indoor areas, C2 for those serving outdoor areas. Partly that's due to very long extension leads typically used outdoors that can defeat ADS by overcurrent device due to the increased loop impedance aren't reasonably going to be needed indoors, and partly that the machines in unskilled hands that can easily cut through flexes (hedge trimmers, lawn mowers) again aren't to be expected indoors, and outdoors connection with Earth potential is far more likely. For industrial settings, some extra judgement will be needed depending on the exact circumstances. If the floor is reasonably insulated from Earth (usually is via the damp proof membrane) and the workforce reasonably trained, the hazard from the cut flex for example may be quite small - both in terms of likelihood of it occurring and the chances of a serious shock if it does. If sliced flexes are a regular occurrence than there are bigger H&S problems than can be addressed by an RCD (since fatal shocks can be had from L & N). On the other hand some fabrication areas are more like outdoors if with a bit of shelter from the rain. It all depends... 
 - Andy.

mapj1 · Answer

It may be that had there been water or animals or naked bodies the inspectors opinion would have veered towards a C2, these being things that up the risk. Sounds like fully clothed and instructed persons rather than random public, so less risk of large area contact shocks, or drunken horseplay, maybe there is a process for inspecting those tools and reporting cut extension leads that mitigates quite a lot of the risk as well ? Is there a risk in the opposite direction that if the power went off mid weld or whatever suddenly someone could be hurt by that? all things that need to be weighed up - doing an inspection well is not a simple tick box job. AND c3 is NOT 'do nothing', rather it is an early warning to start thinking about improvement - can some sockets be changed to RCD types during maintainence and the rest risk assessed properly? could RCDs be added? just not so serious to be an immediate 'stop the job'. Mike.

Coding for Sockets Following EICR

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