To work live or not??

[benji]

As in previous threads it,s down to risk assesments and method statements and don,t forget it,s your engineer that you work for who should write the risk/method statements and only if you agree with the statements you will sign them and procede to do the task.The chances of isolating a db in a hospital are nil ,and even with a very experienced electrician just taking the cover off say a 24w tp dis board it,s easy to trip a breaker.If youve got to fit a new mcb into said board you should be ok with a single pole but triple poles are a nightmare due to the metal clips that hold the breakers together.
But if everything is in place and everybody knows what they are doing and everybody is aware of what is happening (including the effected wards ) ect. it should be well within the scope of a experienced electrician to complete the task.

yours benji

 

[jase]

on Quite a lot of boards you cant take the cover off without turning it off, so just fitting mcbs for the new consumer unit would not happen unless the board was switched off even for a minute

 

[Scud]

Think what you like, but a few weeks back I was talking to a Scottish Power spark down a hole in the pavement.

He was repairing a damaged piece of cable - it was only 230V to earth - just your normal street ring-main....but he was working Live!

He had on 1000V insulated gloves and was joining a new section of cable to supply the street - he could hardly switch it of at the sub-station

Also, have you not heard of cable jointers - 11 KV cable jointing - working live!

As they do when working on Pilons - they're hardly going to switch the national grid off.

Sometimes you have to work live - The EAWR doesn't say you can't, it says you shouldn't:

• In other words, if the above criteria are met, then you can work live

Firstly, the jointer was wearing Class 1, 7500V gloves. SP doesn't issue 1000V gloves to anyone. Secondly, as you rightly say, the EAWR does make provision for working live. However, inconvenience alone can never be a criterion for live working. Another mistake you made is that linesmen on pylons do not work live-ever. That is an establsihed fact. There are specialists who work live on HV lines by being dropped onto lines from a helicopter, wearing Farday cage suits. There are also 'rubber glove' temas who work from insulated hoists on up to 11kV only. None of this is relevant to the issue at hand. In the hospital scenarion, not only would no court in the land entertain a claim by someone who says they were todl to work live and got injured as a result, they themsleves would be liable to prosecution under Section 7 of the Health and Safety at Work Act, having breached the EAWR, Regulation 14.

No person shall be engaged in any work activity on or so near any live conductor (othet than one suitably covered with insulating material so as to prevent danger) that danger may arise unless-

(a) it is unreasonable in all the circumstances for it to be dead; and

(b) it is unreasonable in all the circumstances for him to be at work on or near whilst it is live; and

(c) suitable precautions (including where necessary the provision of suitable protective equipment) are taken to prevent injury.

Note that in (a) the phrase 'in all the circumstances' is used.

Among other things, I teach the EAWR, and I can assure you that the circumstances that the OP talks of would never be accepted as criteria for live working, and anyone who advises him otherwise is being extremely naive, not to mention irresponsible. However, if the OP is still not sure, and I can see no reaosn why you would take the word of a perfect stranger like me, I would suggest a phone call to the HSE for advice.

 

[WayneL]

Firstly, the jointer was wearing Class 1, 7500V gloves. SP doesn't issue 1000V gloves to anyone.

The chap I was talking to was working on a 230V domestic supply cable and was wearing Class 0 1000V gloves:

INSULATING GLOVES, INSULATING BOOTS, ELECTRICAL SAFETY GLOVES, HV GLOVES, LINESMANS BOOTS

However, inconvenience alone can never be a criterion for live working.

The hospital scenario presented would hardly be labelled 'inconvenience' - they could have equipment that cannot be turned off.....life support, for instance.

Another mistake you made is that linesmen on pylons do not work live-ever. That is an establsihed fact. There are specialists who work live on HV lines by being dropped onto lines from a helicopter, wearing Farday cage suits. There are also 'rubber glove' temas who work from insulated hoists on up to 11kV only.

The conductors are either live or they're not - regardless of how they tackle the job or what equipment they use.

No person shall be engaged in any work activity on or so near any live conductor (othet than one suitably covered with insulating material so as to prevent danger) that danger may arise unless-

(a) it is unreasonable in all the circumstances for it to be dead; and

(b) it is unreasonable in all the circumstances for him to be at work on or near whilst it is live; and

(c) suitable precautions (including where necessary the provision of suitable protective equipment) are taken to prevent injury.

Note that in (a) the phrase 'in all the circumstances' is used.

I have already quoted the regulation above.

Bottom line is, the EAWR do not state that you must not work live - they are saying that if it is unreasonable not to, then all necessary precautions must be taken - just like in Inspection and Testing....I'd like to see you measure Ze or PFC without working on live conductors

 

[Scud]

"The chap I was talking to was working on a 230V domestic supply cable and was wearing Class 0 1000V gloves:"

Then he was working contrary to company regulations. ScottishPower do not approve the use of Class 0 gloves under any circumstances. We have no cables buried under streets which are single phase. A jointer may work live under the auspices of SP's Live Working Manual, but only in certain circumstances. Of course, they will never expose two phases at once,nor will they expose a line and neutral conductor at the same time, ergo, they only ever work on either a single line conductor or a neutral conductor. 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.

"The hospital scenario presented would hardly be labelled 'inconvenience' - they could have equipment that cannot be turned off.....life support, for instance."

All hospitals are required by law to have backup systems cap[able of maintaining vital services for a protracted period in the evnt of a power cut. I'm afraid that one doesn't bear close examination.

"The conductors are either live or they're not - regardless of how they tackle the job or what equipment they use."

Agreed. However, you stated that linesmen on pylons work live. They do not. Ever. You can't climb a pylon and gain access to HV cables (pylons carry a minimum 132kV) without killing yourself. All HV work above 11kV is carried out dead in SP's area.


"Bottom line is, the EAWR do not state that you must not work live - they are saying that if it is unreasonable not to, then all necessary precautions must be taken - just like in Inspection and Testing....I'd like to see you measure Ze or PFC without working on live conductors "

I will concede your point in this case, although I maintain that the circumstances presented to us by the OP would not hold up in a court of law as 'reasonable'. It is the responsibility of the hospital under the HASAW to protect the safety of its workers and of any contractors working on their premises.

 

[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!!