Safe Isolation - recent case

[adam2]

You'd think they'd at least have a voltstick in their pocket.

 

 

A voltstick wont detect a live armoured cable, or other types with a metallic covering (FP200, MICC etc.)

A voltstick only works on bare conductors or those covered only with insulating materials such as twin and earth, flex, singles in plastic conduit etc.

 

If an armoured cable has been severed or damaged such that the cores are exposed, then a voltstick would detect this. In practice though it would be extremly unwise to touch or even closly approach such a damaged cable. Remember that if the cable is a 230/400 volt street main, then someone will have reported loss of supply to the power company, whose first action is to try new fuses in the substation!

 

The risks of contact with buried cables may be reduced by use of plans and cable locating devices.

The risks to the CABLE may be reduced by very cautious hand excavation, in order that any buried cable may be gently exposed and avoided or worked around with little risk.

 

The risk to the PERSON may be reduced by use of mechanical excavating plant, striking a buried cable with such plant can produce a loud (and very expensive) bang but does not normally endanger the operator.

 

Workers in the entertainment industry are seldom exposed to risks from buried cables, but as pointed out by others, it could occur when erecting marquees or similar, or burrying cable for large outdoor events etc.

[KevinE]

Yeah I know how a voltstick works.

 

The worker in question was replacing the lamp standards in a carpark. Unknown to him, they were switched in groups with several columns fed off one group photocell. (this is common on dual carriageways as well..I guess it saves the cost of individual photcells). After successfully replacing 3 columns (all off one cell) he moved to the fourth which was part of another group with its own photocell. These lamps were actually live but switched off as it was daylight, he assumed they were isolated like the previous lot and they werent, unfortunately the photocell activated as he was in mid-connection and powered that group up, with the results we've read about.

 

The contractors were fined 70 grand.

 

Here in Staffordshire the county council have replaced every streetlamp in the county over this last couple of years, my office window overlooked a long road and I was able to observe the column-changing procedure. The contractors planted the new columns next to the old ones, pulled the wires out live and taped them up and pulled them out of the column and threaded them into the new ones, pulled the tape off and inserted the live wires into the new terminals at the base of the new lamps.

[Stan Hope-Streeter]

The contractors planted the new columns next to the old ones, pulled the wires out live and taped them up and pulled them out of the column and threaded them into the new ones, pulled the tape off and inserted the live wires into the new terminals at the base of the new lamps.

And I bet everybody in the chain of command had a filing cabinet full of risk assessments and method statements, to "prove" that this didn't happen on their watch...

[Abbott]

As we all know safety and health plays a vital role. These rules should be strictly implemented by the government or local bodies to avoid further tricky situation. What you stated is exactly correct; Proper training and set guide lines should be properly implemented and made changes accordingly from time to time. It would be applicable not only to the electrical works but also to the manufacturing industries.

[KevinE]

I dont know, I cant see any other way of doing it as (like down my street) the streetlamps are just spliced into the main underground SWA cables that run round the estate, the lamps have their own local isolators and mcb's under those little flaps at the base, to make it safe for contractors to change the lamps and/or lamp heads/gear trays..but as for the whole lamp standard, well, looks like they just do what I said I saw through my works window.

[Roderick]

These rules should be strictly implemented by the government or local bodies to avoid further tricky situation.

I disagree with that. These rules should be implemented by every sane person, without relying on Government or someone else.

You wouldn't cross a busy road without looking or expect someone tell you that you must look before you cross.

As long as we keep looking at H&S as something that is implemented by someone else rather than part of the job at hand, these things will keep happening.

[paulears]

I agree with Roderick, I always squirm when I see those ads "I was installing a burglar alarm, and had been given the wrong ladder" - so surely, somebody who knew what they wqere doing should have been bright enough to realise the problem? We always blame the bosses, when for them to make totally certain all is well, they have to be there, on site, watching and monitoring - which is not viable. We must accept responsibility for getting it wrong. When I had an accident last year, it was totally my fault - and it would have been wrong for me to blame the owners, which, no doubt, if I had reported it, would have at the very least got them a fine, and cost a lot of money in changes to the system.

 

This entire topic is based on accidentally working with live conductors. In the dim and distant past, I remember my instructor always saying - treat every conductor as if it is live, unless you personally made sure it wasn't, and remained that way. I've always checked before touching, and when not quite certain, checked again. I did get this wrong once - the very time I didn't check, and it scared me!

 

These people should have checked, they didn't and that's that!

 

People work on live cables every day, and take appropriate steps to ensure safety. When people assume, it goes wrong.

[DangerousMark]

I suppose there's not checking when you should have known, and not knowing that you should have checked ... which is probably one part training, one part beaurocracy getting in the way or something.

 

I managed to kill a car ECU (in a way that then required changing the engine oil before it could run again - long story) because an earth lead got knocked loose when I did head work on it. Did I know about the importance of earths to an engine before it shuddered to an ignoble halt and I found the smouldering mess of burnt insulation? Nope..... mind you that was me as a private individual working off a service manual and the goodwill of online helpers, but neither of them said anything about it either. And I think any of us who have undergone training events or even courses in professional settings know how badly they can be run and how much they get ignored :blink: (shockingly) - but you still get a certificate for attending (food safety amongst others) or for completing the 10-question test thing at the end correctly (with someone watching over your shoulder and calling out which letter option it is --- fire safety). Heck, I even had some I could hardly remember any details of (because they were rubbish, and the rest of the training load was too heavy for the shorter - and more important - parts to sink in) on my CV for a certain desperate period.

 

Guys working on a demolition site across the way managed to kill our internet by slicing a 2m-deep, recently laid and should-have-been-known-about fibre optic cable the other day. From some of these stories now I'm just glad there weren't any power cables (or at least, any that have been yet "found") running across there that didn't feed the actual demo site so weren't still live... could been quite a big bang and, ahem, a shock for the contractor besides killing all our IT, non-emergency lights, electronic door locks, refridgeration, IP/PBX phones...