To work live or not??

[Scud]

Hi

I was wondering if anybody can shed some light on this.
I am working on a job in a hospital and they want to run in some
new circuits for tv's in all the wards. They have an excisting
3 phase board but want to install consumer units next to
the 3 phase board to tap off from to the new consumer units.
I have been told that this have to be done live as they can
not isolate the main board for obvious reasons. Needless to
say i am not to keen on this idea. When i was doing my 2360
i was told to never work live as there is no reason to take
the risk and that a supply can always be isolated if need be.
Also can i refuse to do the job under Healt&Safety laws?

Many Thanks for your advise.

Yes you can. In fact, if it is unreasonable to work on or near live conductors, you have a legal obligation to refuse to carry on. It is never a defence in law to use 'I was following orders'. You have the full protection of the law. The call is yours to make.

 

[WayneL]

The only PPE approved for use when working on or near live conductors is Class 1 gloves, full face visor and flame retardant overalls of the approved pattern, complete with full chin flap. I'm not guessing at this, as I said, I teach this stuff to SP operatives and contractors requiring authorisation on the SP network.

To be honest, Scud, he didn't have any of this stuff. He was down the hole with his gloves on. (Maybe he preferred the thinner ones).

I know you are probably right about this, so he was probably taking his chances with regards to correct PPE - like you see with builders/roofers/motorway- contractors when driving around - no high vis, no hard hats, no ear defenders.....the list goes on and on.

He said he served his time with the old Manweb and had worked there twenty odd years - people can get complacent over that time, I suppose.

I wasn't advocating working live, by the way, I am a stickler for safe isolation - if anything, I'm too cautious - but times do come where you have to assess the risk and decide whether to proceed.

Just re-reading the OP, am I right in assuming he's 'employed' and is asking whether he should refuse to do the job to his boss (on HSE grounds)?
Or is he a contractor and wants to turn the job down?

 

[maslg]

Hi

I was wondering if anybody can shed some light on this.
I am working on a job in a hospital and they want to run in some
new circuits for tv's in all the wards. They have an excisting
3 phase board but want to install consumer units next to
the 3 phase board to tap off from to the new consumer units.
I have been told that this have to be done live as they can
not isolate the main board for obvious reasons. Needless to
say i am not to keen on this idea. When i was doing my 2360
i was told to never work live as there is no reason to take
the risk and that a supply can always be isolated if need be.
Also can i refuse to do the job under Healt&Safety laws?

Many Thanks for your advise.

Hii with regards to live working you need to look at electricity at works act 1989 with regards to working safely ,there are 16 regulations refering to low voltage system which state the precautions that have to be in place to work on live systems i.e. adequate light,space,and acces. Hospitial require a (ups) uninterupted power supply therefore you may require a permit to work.

 

[maslg]

Its only illegal if a safe system of work is not in place and at a hosiptal you have to have a safe system of working the next part is from EAWR1986 REG 213 The system of work should: allow only people who are competent to do so to work on or near exposed, live conductors .

LINK:http://www.hse.gov.uk/pubns/priced/hsr25.pdf

 

[Knobhead]

Most 3Ph boards are safe to work on live so long as you’re not exposing any bus bar connections.

Underground LV jointing is carried out live and has been stated no two conductors are exposed at the same time. This may involve temporary shrouding of the neutral while work is done on a live conductor. If you noticed the jointer would probably have been stood on a 1000V insulating mat. All tools would be insulated.

MV working. Under no circumstances is this done live. Each end of a cable or line will have a Circuit Main Earth (CME) applied. If a cable is to be cut then it will be spiked, IE it will have an explosive bolt fired through the earth shrouding (CPC) to all 3 phases. Before cutting the CPC an earth continuity strap will be attached to each side of the work area, if required an earth spike will be driven and connected to the earth continuity strap. Over head lines will have a temporary earth spike no further than one poles distance in all directions from the point of work to connect all conducers to earth. If in the opinion of the linesman there is a possibility of lightening all work will be suspended.

Live working on MV systems is to be avoided if at all possible. A “Sanction to test” certificate stating the nature of the test must be issued, it shall also state the limitations of testing. While MV testing is carried out the area will be restricted access.
I’ve worked under a Sanction to test a few times, it makes my flesh creep!

 

[Harry Worth]

This may help a little. The Electricity at Work Regulations are mandatory and enforceable by law. I've dug out the relevant section -

Regulation 14 – Work on or near Live Conductors
Status – Absolute (Absolute – Regardless of any cost or other consideration.)
No person shall be engaged in any work on or so near any live conductor (other than one suitably covered with insulating material so as to prevent danger) that danger may arise unless:
It is unreasonable in all the circumstances for it to be dead and
It is reasonable in all the circumstances for him to be at work on or near it while it is live and
Suitable precautions (including where necessary the provision of suitable protective equipment are taken to prevent injury.

 

[netblindpaul]

Most 3Ph boards are safe to work on live so long as you’re not exposing any bus bar connections.

Underground LV jointing is carried out live and has been stated no two conductors are exposed at the same time. This may involve temporary shrouding of the neutral while work is done on a live conductor. If you noticed the jointer would probably have been stood on a 1000V insulating mat. All tools would be insulated.

MV working. Under no circumstances is this done live. Each end of a cable or line will have a Circuit Main Earth (CME) applied. If a cable is to be cut then it will be spiked, IE it will have an explosive bolt fired through the earth shrouding (CPC) to all 3 phases. Before cutting the CPC an earth continuity strap will be attached to each side of the work area, if required an earth spike will be driven and connected to the earth continuity strap. Over head lines will have a temporary earth spike no further than one poles distance in all directions from the point of work to connect all conducers to earth. If in the opinion of the linesman there is a possibility of lightening all work will be suspended.

Live working on MV systems is to be avoided if at all possible. A “Sanction to test” certificate stating the nature of the test must be issued, it shall also state the limitations of testing. While MV testing is carried out the area will be restricted access.
I’ve worked under a Sanction to test a few times, it makes my flesh creep!

Tony,
Please remember there is no such thing as MV in the UK, there will be those who understand, but, the students new entrants will not as it is not a recognised supply definition under UK statute law.
Electricity is either LV or HV in the UK end of.
Sorry.

 

[ackbarthestar]

Hi

I was wondering if anybody can shed some light on this.
I am working on a job in a hospital and they want to run in some
new circuits for tv's in all the wards. They have an excisting
3 phase board but want to install consumer units next to
the 3 phase board to tap off from to the new consumer units.
I have been told that this have to be done live as they can
not isolate the main board for obvious reasons. Needless to
say i am not to keen on this idea. When i was doing my 2360
i was told to never work live as there is no reason to take
the risk and that a supply can always be isolated if need be.
Also can i refuse to do the job under Healt&Safety laws?

Many Thanks for your advise.

There are a few things that you haven't made clear and just out of interest
1/ Who told you you can't turn off the 3ph DB?
2/ What does the DB supply?
3/ Will permits to work be signed and will the necessary PPE be available?
4/ Have you had the necessary training to work live (2360 is not a live training course)?

As you can see I'm starting the 'risk assessment' approach by asking questions that will limit the risk by exploring all the possibilities. I should satisfy yourself that you know the answers to all these questions before you make any decisions.

 

[Knobhead]

Tony,
Please remember there is no such thing as MV in the UK, there will be those who understand, but, the students new entrants will not as it is not a recognised supply definition under UK statute law.
Electricity is either LV or HV in the UK end of.
Sorry.

OK, but is the rest correct?

 

[Engineer54]

OK, but is the rest correct?

There is nothing wrong with or in your descriptive post Tony, including the term ''MV''. Which just about every institution, Engineer, Supplier, Contracting company etc, involved in this area in the UK refers this voltage band as, ....so it's far from ''end of story!!'' It's not our problem that our BS system is 30 years out of date with everyone else.

As for the students just coming into our profession, most will have no dealings whatsoever with anything over 1KV. Those that are interested will ask, and can be correctly informed. Blindly ignoring the fact that this is an international recognised voltage band is nonsense. As is the failure of our BS system still holding on to LV and HV, when no-body else that is involved in this industry area is, in the UK!!! All it achieves is to cause ignorance and confusion all round!!

 

[alarm man]

i would have thought working live in a place like a hospital would be valid,but only by qualified people with the right ppe and training and those fancy million volt tool kits,ive seen nedl work live in a factory after vandals had smashed the meter and fuses off,they had all the kit and the second man was there with a stick to push him off if it all went wrong(i was gonna say pull him off,but i can hear tittering at the back already) was very interesting to watch,but there were trained to do it,the reason for it was they said they cant switch it all off as would affect production for the surrounding factories.

 

[cagedanimal2010]

i hope this job has been done by now!!!

 

[Engineer54]

I have two observations to make, one relating to the OP, and one on hospital emergencey supplies.

1/ Apart from making a means of entry to these 3 phase distribution boards, what will you be working live on?? The tails for the adjacent CU will be connected to the dead side of a CB or fuse carrier that just leaves the neutral and CPC conections!!! Why would you need to kill power to the 3PH DB?? That work should be well within the realms of a competent electrician, ....Surely!!!

2/ Hospital essential emergency supplies operate at a higher level than local distribution boards, any failure on downstream DB's will not initiate any change-over. Contrary to popular believe here, there are ''Few'' areas in hospitals that will be covered by UPS systems. General ward areas will most certainly not be so covered.

The areas of that will have UPS systems, will be generally limited to operating theatres, cesarean delivery rooms, specialised medical rooms, central blood bank area, etc... There maybe also be small essential appliance based UPS modules scattered about as required.

 

[maslg]

Hii with regards to live working you need to look at electricity at works act 1989 with regards to working safely ,there are 16 regulations refering to low voltage system which state the precautions that have to be in place to work on live systems i.e. adequate light,space,and acces. Hospitial require a (ups) uninterupted power supply therefore you may require a permit to work.

and dont forget ventilation,at the end of the day if Scudd does his own risk assessment and feel he could harm himself or anyone else then he should not work live its his call regaurdless of what any regulations states.Regulations are there for giudance.

 

[Knobhead]

I think E54 you’ve hit on the nub of the matter, “competency” to carry out a task. One of the first things I was shown was how to protect cables when drilling in to a live DB, it’s not rocket science.

Some very old boards I would be dubious about but I’ve not seen a 200A open frame board for 20+ years and we had plenty of them. But again if you knew what you were doing they were no problem. I used to enjoy working on them, but then you all know I’m MAD

View attachment 7787

 

[Des 56]

I cant ever remember switching off a bus bar chamber to terminate a cable until the final connections were needed,silly me I know

Its amazing what protection a piece of plyboard shoved in and 1mm single strapped diagonally across the cover fixing holes can provide to the mindset, it provides a mental block against poking your fingers in where they shouldn't go

I know the post will get panned by the H+S freaks,but that was the reality of expectations

 

[Engineer54]

I cant ever remember switching off a bus bar chamber to terminate a cable until the final connections were needed,silly me I know

Its amazing what protection a piece of plyboard shoved in and 1mm single strapped diagonally across the cover fixing holes can provide to the mindset, it provides a mental block against poking your fingers in where they shouldn't go

I know the post will get panned by the H+S freaks,but that was the reality of expectations

Talking of bus bar chambers, i wonder what the H&S would have to say about drilling them live for new cable bolt connections. I've had to do that in the past, albeit with supervision, ie, a guy with a decent sized lump of wood, just in case so to speak!! As you say Des, that was part and parcel of the real world of expectations of electricians, ....and i was still training at the time!! lol!!

 

[netblindpaul]

OK, but is the rest correct?

I believe it is Tony

 

[netblindpaul]

There is nothing wrong with or in your descriptive post Tony, including the term ''MV''. Which just about every institution, Engineer, Supplier, Contracting company etc, involved in this area in the UK refers this voltage band as, ....so it's far from ''end of story!!'' It's not our problem that our BS system is 30 years out of date with everyone else.

As for the students just coming into our profession, most will have no dealings whatsoever with anything over 1KV. Those that are interested will ask, and can be correctly informed. Blindly ignoring the fact that this is an international recognised voltage band is nonsense. As is the failure of our BS system still holding on to LV and HV, when no-body else that is involved in this industry area is, in the UK!!! All it achieves is to cause ignorance and confusion all round!!

Tony's descriptive post is correct E54 as you say.
However it is not just the UK standards that are out of kilter with the rest of the world, it is our statute laws as well.
We get enough problems explaining to people that 400/415 volts is Low Voltage let alone bringing in a term that is not included in any UK standards, or UK legislation.
You know I understand your terms, as does Tony and many others.
I still though believe that as this is a UK based forum, and I have been told quite forcefully recently that my posts were unhelpful and insulting to other members for even suggesting that they were perhaps doing something that there should not be any confusion wrt using the correct terminology as detailed in UK law & standards.

 

[netblindpaul]

There are many of a certain age who have worked live, for shame!

Thing is now it is frowned upon, just like updated regs books we have to move with the tide.

One reason for it is the reduced competence of those being trained now, so they have to reduce the risks.
Training now is not what it was.

One comment on the hospital works.

When I work at my one of my local hospitals in their DB's I am not allowed to do my own isolation, nor even open the DB cover!
Their electrical engineer comes along, we test, we isolate, we test, he locks off, issues a ptw then we work.
Following this the process is reversed.
SO as far as working live in a board goes, in my local area no chance!