Log in to the online community

Want to post a reply? You'll need to log in
John Peckham
518 Posts
I have not seen on this forum much about the mandating 30mA RCD protection for all sockets with the removal of the Risk Assessment exception in the AMD2 DPC. 

Not to many objections on the DPC website.

Any views?
8 Replies
2013 Posts
I've yet to post any of my objections on the BSI web site - but rest asurred they're on their way...!

Mine will be a repeat of last time - bad idea for IT server rooms etc where you have non-electrical people wanting to re-configure supplies, often 'under duress' (main production system is down and management are jumping up and down because of the amount of money that's being lost every minute) - perfectly safe for IT bods to do using plugs & sockets, absolute nightmare if they're hard-wired. Of course 30mA RCDs are a complete non-starter due to earth leakage with racks of IT equipment.

   - Andy.
351 Posts
Seems like the IET'S manufacturer Masters are attempting to rinse every ounce of sales potential out of the new amendment - the stench of scientific atrophy is becoming overpowering, what with this and the push for compulsory AFDDs, why not dispense with BS7671 altogether, and make the manufacturer's recommendations compulsory instead - because it it reading that way right now.
Agreed. The exception needs to remain for offices and rooms with lots of IT equipment.
Quite happy to mandate notices like "not to be used for portable equipment" or similar.
Chris Pearson
1887 Posts
But is something which says, "if I fit an RCD, the equipment won't work" a risk assessment?

Isn't it more about who is permitted to plug in what. So the office cleaner cannot unplug the servers during her rounds and in any event, why does her (or his) regularly PAT tested floor polisher, which is also properly maintained, present a risk?

The problem with the current reg. is that it only requires a documented risk assessment, not a competent one! In answer to JP, I'd keep things as they are, but I have no strong feelings.
I think offices - desks in particular - are an environment that receives little added benefit from RCD protection to the sockets;

In general you cant leave the equipotential zone from your desk?
In General there's not a load of electrically dangerous equipment being plugged in surely that cant be taken care of by the plug or circuit fuse? 
In general there's probably not a lot of class one equipment being plugged into the common desk space? 
Most offices are run by someone with some idea of health and safety and the general desk worker is not very likely to DIY the electrics in his/her environment?
PA Testing is more common in most offices.
Correctly designed circuits on an MCB should be sufficient surely?
If you had RCD protection for the common tea point/kitchen and the designated cleaning sockets - surely you've minimised the main risk areas, considered additional safety for the end users and given a very good design to cost ratio? (obviously the "best" design would be one that had an individual RCD for every socket. 

But most of all given all of the above, the additional costs involved to RCD protect every socket in the office environment is just eye watering exorbitant. (This is what I do for a living so I'm not complaining when the maintenance manager asks me to install one gazillion RCD sockets or RCD tap off leads to every single desk - as putting the RCD in the riser cupboard where all of the underfloor bus bars are supplied from is a bad design - but this does get done a heck of a lot too. 

I remain unconvinced by the absolute need to RCD protect everything; but I'm a cynical guy; about RCDs, AFDDs and blanket surge protection............umteen years without all of that was fine, (specifically in the office environment here) but now its virtually mandatory because its a better design and better safety factor. Catch 22 really. Cost vs safety. Obviously there are higher risk areas where all of the above should be absolutely mandatory; they all have their place in the electrical environment for sure. 

Kind Regards
1256 Posts
There is no such thing as an equipotential zone.

From the employer's perspective, individuals may bring in their own equipment and connect.

Whilst there's not a lot of Class I equipment, unfortunately the ICT environment often involves a lot of wired-interconnected equipment, that provides fortuitous earthing.

A lot of offices are run by people who have no clue about the above, and a lot of portable equipment often is missed in portable appliance testing for one reason or another.

Correctly designed circuit on an mcb don't catch the situations where people cram in European plugs into UK socket-outlets, which omits the protective conductor connection, or where adaptors are used that somehow omit the PE connection.

Having said that, I'm not personally convinced (and I don't think, in the end, nor was the inventor of the device) that RCD's are the panacea of protection they are often held up to be.
3370 Posts
However if installing AFDD they could incorporate RCD protection as standard as well as being a MCB.
3370 Posts
However if installing AFDD they could incorporate RCD protection as standard as well as being a MCB.

So omitting RCD protection could become more challenging.


Log in

Want to post a reply? You'll need to log in