I would be inclined to agree with those above who have queried the relevance of the number of phases... working live on single phase boards is still working live!

On the other hand it might be worth taking note of the fault rating, as this will have a bearing on arc flash and hence PPE, and the protection upstream (RCD or not etc).

Good morning Daniel

Can we assume that you have carried out your formal Risk Assessment of the activity  in accordance with the Management of Health and safety at Work Regulations 1999 and applied the appropriate control measures? Having done that have produced a Method Statement and communicated that to the workforce?

As a supervisor you have read and understood the requirements of the  Electricity at Work Regulations 1989 and in this case are applying the requirements of Regulation 16 and 14?

Is your company meeting the Statutory requirements of the Health and Safety at Work Act 1974 and in this case especially the requirements of Regulation 2C? Do you have records of your staff qualifications, competencies and CPD? Are you going to site and assessing and coaching them? Who is authorizing individuals to do what?

Are you personally, as a supervisor, meeting your personal requirements under Section 7  of the Health and Safety at Work Regulations 1974? I was in court to see a QS charged and convicted in the Crown Court of failing to supervise under Section 7 for countersigning fraudulent Electrical Installation Certificates without ever going to site that had been completed by an electricians mate. Google the Emma Shaw fatal accident case.

Does your company have a Health and Safety Policy that names and defines roles for employees?

Do you have a draw full of nice documents or do you have an active applied safe system of working?

JP

Really appreciate all your input, We do follow the correct H&S advice we have our own H&S department which are very proactive. I do agree we should be isolating the boards. In an ideal world situation that's fine, but to shut a whole sheltered housing scheme down to change and test a new socket front I would suggest that would come under unreasonable if it means shutting down lifts, fire alarms, CCTV etc which could all cause a problem and concern to the tenants. Health and safety as we know is about balancing the task against the risk and how we can reduce that risk. I have read the documents you suggest above and in regulation 14, 210 it talks about having two people. 

210 People whose presence near the live conductors is not necessary should not be so near the conductors that they are at risk of injury. However, there may be occasions when people who do not normally need to be in the vicinity of live conductors are required to be present, e.g. those assisting or recovering a casualty after an incident. Appropriate measures must be put in place to protect them.

I have created a 9 page document showing our legal requirements and what questions we need to answer. I realise the importance of getting this right.

So the general consensus I'm getting from this good discussion is regardless of circuit types,  the board should be made dead before any work commences.

And yes we have a whole filing cabinet follow of method statements, processes relating to every topic under the sun.

Thank you all once again for your advice and support.

bs-76712018-model-forms-minor-electrical-installation-works-certificate.pdf (theiet.org)

Daniel S Robinson said:

In an ideal world situation that's fine, but to shut a whole sheltered housing scheme down to change and test a new socket front I would suggest that would come under unreasonable

Is this socket front somewhere special such that you cannot isolate and lock off just the one circuit?

Slightly to one side, but a thought: If you are expecting to have to work on the switchboard frequently enough to be a genuine problem and cannot isolate the whole panel due to essential loads or operational demands, perhaps the design should be reconsidered e.g. Form 4 switchboards, essential services on a separate DB and/or alternative (UPS) supplies?

The horse may appear have bolted but on the other hand it may well be more cost effective to re-fit compared with the safe alternatives.

Or, of course, isolate properly but schedule the works to be less of an inconvenience e.g. by holding the minor items and doing multiple jobs at once.

I do like that idea of splitting things up, these are old installs but that could be an option. What I have been doing in my county is get the operative to do an earth loop and RCD tests if present and Lim the rest stating three phase board unable to shut down. This is if its a socket, light type replacement.  We test all our property's every five years so it will get IR tests then. As its communal type areas no one is touching it in-between time so balancing need against risk I think that works. For any thing else I think I'm with you guys turn it off.

Hi Dan,

In my experience in the Navy, working on live equipment is an absolute last resort and will require a qualified Risk Assessment manager to fill out a Risk assessment to conduct any work. If you are unable to work on the equipment dead, then it is paramount for the safety of the person carrying out the task to have a safety number with a life saving insulated hook and both persons to be using correct PPE. 

Regards,

Kelly

Sergio Fernandez said:

Why can it not be isolated?

Tests for Ze and Zs are by their nature live tests. As are polarity tests.

Safe isolation itself is a live testing procedure until it's complete.

But back to the HSR25 guidence on Reg 14 -

1. is it unreasonable in all the circumstances to for it to be dead? yes, because you can't do the test when dead.
2. is it reasonable in all the circumstances for him to be at work or near whilst its live - yes because they are competent, qualified and converse with GN3 etc.
3. are suitable precautions taken to prevent injury? Beyond e.g. GS38 this is very much subject to the individual circumstances. There's a note in HSR25 para 215 about accompaniment which suggests that simple live electrical tests can be done safetly but manipulation of conductors etc can't.

I'm not sure that doing e.g. a Zs test on a 3 phase DB is substantially more hazardous than on a single phase DB. Many 3 phase DB's are quite well constructed such that there's a substantial cover over the incoming terminals which can help justify working on a DB isolated at its own main switch.