RCD omission risk assessment

[Nigel]

It boils down to our customers stating they don’t want RCD protection but not willing to state that in a documented risk assessment. If we installed RCD protection then technically we’re in breach of contract and liable for any outage costs and fines that can run into the hundreds of thousands per hour.

But surely as the competent people (electrically) only you can do the RA. It needs to have some technical back-up to it and cannot just be at the client’s request but in this instance I can see it being quite simple to RA RCD protection off certain sockets.

 

[Strima]

But surely as the competent people (electrically) only you can do the RA. It needs to have some technical back-up to it and cannot just be at the client’s request but in this instance I can see it being quite simple to RA RCD protection off certain sockets.

This has come from the customers various design and engineering departments, they’re classed as electrically skilled and normal carry out the circuit designs yet expect us to raise and sign the RA. Peeing into the wind is the norm in telecoms.

 

[45140]

There is another way.
Why not get the Customer to instruct - "confirm" - in writing that they wish RCDs to be excluded for operational purposes.
Your Company then produces a RA that demonstrates that there is no danger created as a result of excluding the RCD. They submit the RA to the client stating that "...in accordance with your Instructions, and in compliance with the requirements of BS7671, we have produced the relevant risk assessment to remove the use of RCDs in the locations/circuits identified by you. Please let us know within xx days, (whatever), if you do not agree with the risk assessment, otherwise we will proceed along as Instructed by you...."

All that the law requires is that :-
* the risk assessment has been carried out using personnel who are competent and aware of the hazards and risks ;
* that the risk associated with the hazards have been assessed against the existing BS7671 requirements and that where necessary suitable and sufficient control measures have been put in place that achieve the same or a better level of safety, and ;
*that the risk assessment has been documented

You have now complied with BS671 in respect of departures from the requirements in proving that this request has not resulted in a reduction in safety.

Remember HSE are NOT looking to second-guess the RA, they want to see that the issue has been recognised and appropriate measures taken. There is no legal requirement to be 100% correct in a risk assessment and HSE would not take enforcement action in the event that a genuine error had occurred - as long as you have followed the principles.

 

[James]

I am currently having discussions with a client about a similar matter.
they have several pieces of equipment that are often moved about a factory floor to different machines or locations.

most positions that they would like to plug the equipment in are close to an outside door, most are near large tanks of water, water on the floor is a likely hazard.

equipment involved is mostly single phase but some 3 phase, inverter drives and servo drives in a lot of them.

what they are finding is that the rcd's are tripping when being used.

so customer asks me, can you put in some sockets that are not rcd protected for the equipment we move about?

I say no, it cant be done unless sockets are over 32A, or a documented risk assement is done.

can you do a risk asses for me?

I say, I can but you wont like the result.

they are quite pragmatic about it, end of the day they need to move stuff around to manufacture what they make.

Is the simple answer to provide 32A sockets all over the shop floor to power these pieces of equipment and as such remove the rcd requirement?
p.s. they are probabley 6A single phase or 3A 3 phase requirements.
I understand that the supply cable from plug to machine will need to be made bigger and may well need some over current protection adding to the machine.

 

[Strima]

The regulations around additional protection for sockets may work well in a domestic environment but in commercial and industrial they're starting to prove a little prohibitive in some situations.

 

[westward10]

The risk assessment isn't to decide whether additional rcd protection is or isn't required but to justify its omission.

 

[pc1966]

I understand that the supply cable from plug to machine will need to be made bigger and may well need some over current protection adding to the machine.

Why not a 32A plug with an in-line FCU?

But yes, the whole thing is a bit stupid. There are many cases when non-RCD sockets are needed or desirable and in locations where the risk is managed, having them labled ought to be the first step even if it is backed up by a risk assesment justifying why the are omitted and what steps (training, lables, extra bonding, shorter PAT testing times, etc) are in place to help mitigate the risk.

 

[pc1966]

But back to the OP's original question - are there any examples of how the RA should be done and documented?

 

[James]

Agreed, I would love to see a sample risk assessment.

 

[dodger421]

Agreed, I would love to see a sample risk assessment.

This was actually the reason I bought Codebreakers, Part 2 explains the process of risk assessing omission of RCD’s and gives some useful examples of the things to look for as well as a model form for this particular RA.

It’s not a complete example, but it gives a step for a hint in terms of likelihood and severity and the options the client has depending on the level of risk.

 

[pc1966]

Looks like I need to get a copy of the latest Codebreakers then!

In terms of 32A plugs and equipment not needing that much you can get stuff like this:
https://www.essentialsupplies.co.uk/power/adaptors/32a-adaptors/twin-13a-socket-32a-in.html

 

[Wilko]

what they are finding is that the rcd's are tripping when being used.

I would want to understand this aspect too. Is it normal for the 6A machine to have 30mA of leakage? Or is it that there’s several m/c on one circuit?

IIRC the PowersThatBe are looking to remove the RA exception from 18 Amd 2.

 

[Vortigern]

Maybe a monitoring device to detect what an RCD detects which then signals a relay alarm in the absence of RCD so that if there is the kind of fault the RCD would have detected then there would be an alarm/notification to key workers. i.e. mobile phone alert/audible alarm etc. Not so fantastic as Schneider do such a module that fits onto an existing MCB.

 

[Lister1987]

If you're omitting RCD protection, use sockets that are not standard 1363 ones, some come with a T shape pin, that way only modified equipment can be used, any attempt to circumvent this then puts the onus on the modifier (modifee?) and not the spark as they took methods to ensure a degree of protection (using nonstandard sockets/plugs)

 

[Strima]

If you're omitting RCD protection, use sockets that are not standard 1363 ones, some come with a T shape pin, that way only modified equipment can be used, any attempt to circumvent this then puts the onus on the modifier (modifee?) and not the spark as they took methods to ensure a degree of protection (using nonstandard sockets/plugs)

Look up the definition of a socket-outlet in the regulations, sadly you can't use this method to get around the problem.