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Topic Title: Operational Safety
Topic Summary: Limitation of Access
Created On: 26 October 2012 03:43 PM
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 26 October 2012 03:43 PM
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alanf

Posts: 9
Joined: 17 October 2002

I would welcome opinions on the implementation or acceptance of Limitation of Access procedures on Industrial or Private networks (typically LV-MV).

I have a situation where I am producing an Electrical Safe System of work ( including Permit to Work, Limitation of Access and Sanction for Test etc.,), but I am experiencing strong objections to the inclusion of Limitation of Access in the procedures. Consequently I would appreciate any comments from fellow members who have experienced similar problems and on what grounds the objection were based.

Many thanks

AlanF
 26 October 2012 05:55 PM
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dlane

Posts: 690
Joined: 28 September 2007

Hi,

The Limitation of Access has been removed from our procedures when we moved to a computer based Permit to Work system as it was not within the software.

There were no real objections to its omission as the LOA was really not used that often at the time of the software introduction. In early times before a level of trust had been built up between operations and maintenance, it was used quite a bit. But as time went on, it was felt that the LOA didn't really add any value to our situation, especially where our own staff were utilised.

On the rare occasions of extra paperwork required within the new system the option has been added of issuing a permit to work without any isolations attached to it, or the extra information is contained within the work order, method statement and risk assessment . A Permit to Work Live is issued for Live Working, a Permit Restoration of Supplies is issued to give plant control to maintenance and a Sanction for Test for HV testing on HV apparatus and or removing Primary Earths.

It will depend upon your tasks and type of plant, we have relatively small distribution networks with no open air switchgear. We don't use a lot of contractors for general works where an LOA could be used, they are mostly working on the switchgear / apparatus itself so are issued with a PTW.

Kind regards

Donald Lane
 26 October 2012 08:05 PM
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JonathanHill

Posts: 225
Joined: 09 September 2002

I generally find a LoA very useful, for access to an area containing switchgear, and never received any objection. As Donald, I've also used a PtW document, with the isolations & earthing sections suitably endorsed when no LoA forms were available.

You don't say what the nature of the objections you've received are.

-------------------------
Jonno
 27 October 2012 01:28 AM
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alancapon

Posts: 5745
Joined: 27 December 2005

I agree with Donald & Jonno really.

We use a permit or sanction if we are either working on high voltage conductors, or working within the safety distance of a conductor. Both documents require isolation and a circuit main earth against each point of supply. The sanction allows application of a high test voltage and also the removal of circuit main earths as part of the works.

We would use a limitation if we were working close to high voltage conductors
but outside the safety distance, possibly working on CT circuits of an isolated system or working somewhere unusual that we would want our Control to be aware of, for example working on top of metalclad switchgear with the high voltage conductors still enclosed. We would also use a limitation for working in a confined space.

We do not use permits & sanctions for LV, unless we are working dead and the isolation has to be made at HV.

Regards,

Alan.
 27 October 2012 12:01 PM
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alanf

Posts: 9
Joined: 17 October 2002

Jonno

My objectors argue that on the specific project in question they will (in theory) never require trade operatives to work on or near live or energized appartus (such as main distribution boards etc.,).
Although the idea is good, the situation involves a joint-venture CDM construction site consisting of many trades and temporary electricity supplies (mainly LV). Consequently the freedom to Disconnect, isolate and Earth circuits on major plant items and issue PTW will become very restrictive.
I would prefer to leave the LoA procedure within the Safe System of Work to be used if and when necessary. However my objectors insist on removing all mention of Limitations of Access until it can be proved necessary in the future.
 27 October 2012 12:14 PM
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alanf

Posts: 9
Joined: 17 October 2002

Hi Donald and thank you for your comments.

I am interested in your comment regarding a permit to work Live. As I believe that the principle of the Permit to Work with reference to the Electricity at Work regulations is to make things safe (i.e Dead) rather than make things live. How do you deal with this?

May thanks

AlanF
 27 October 2012 01:51 PM
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ArthurHall

Posts: 735
Joined: 25 July 2008

A limitation certificate was designed to be issed where verbal instruction were not deemed sufficent to acheve safety. If there is already a writen job card and method statement then I would say that a further bit of paper is not required.
 27 October 2012 09:47 PM
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westonpa

Posts: 1771
Joined: 10 October 2007

Originally posted by: alanf
Hi Donald and thank you for your comments.
I am interested in your comment regarding a permit to work Live. As I believe that the principle of the Permit to Work with reference to the Electricity at Work regulations is to make things safe (i.e Dead) rather than make things live. How do you deal with this?
May thanks
AlanF

The principle of the PTW is to provide a formal and structured control over the work such that it is carried out safely, so far as is resonably practicable. The law does not prohibit dangerous work but rather it is concerned with the way the work is carried out. This was decided at the court of appeal in 1996 at which the judge decided that zoo keepers could go into the cage with tigers in order to carry out their work and that a prohibition notice must therefore be removed, because the work could be justified. Note, one of the keepers had been killed and hence the prohibition notice. Some electrical work has to be carried out live and so providing it can be properly justified and a safe system of work can be implemented then it can be carried out. A PTW can be used to facillitate/control the safe system of work. Different companies of course use different methodologies to suit their particular hazards, risks and plant.

Regards.
 28 October 2012 07:35 PM
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dlane

Posts: 690
Joined: 28 September 2007

Hi,

The PTW Live is the final authorisation for specific live working to be carried out on our sites. Prior to that a live working risk assessment and authorisation are produced that justify the live working based around regulation 14 of EAWR. It just seems to be the way my company has gone for live working.

It is predominantly used on battery systems. When carrying out routine testing and inspection on batteries, the PTW live is issued with the risk assessment and authorisation and specifies the limits of the work and the precautions to be taken.

If we are replacing battery cells or carrying out a discharge test then the load and charger are isolated from the battery and the PTW live is issued with the isolation key attached, but is still classified as live due to the battery.

It was also used when we swapped over supplies into a UPS changeover board. The connections we were working on were made dead, but removing the cover of the board exposed other connections that were live.

It isn't used when we test for dead, although classified as a live working procedure this is covered under a standard PTW or instructions on a work order card. I also don't remember it being used when we tested the earthing system.

Kind regards

Donald Lane
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