Elecricians' safety slipups

[MikeDelta1]

First of all my apologies if it sounds like I'm "teaching my granny to suck eggs" but from some of the posts I have read it's obvious that not all contributors are qualified. So if you are just an enthusiastic DIYer or lack the basics then read on:
A few years ago (must be 25 years at least) when I worked for my local Electricity Generating Board (YEB) I was installing a shower circuit for a customer.
To cut to the chase ('scuse pun) I had installed the cable 6mm T&E. I think 6kw was the average shower back then. I was in the process of terminating the cable into the fuse board (Power was turned OFF) but nipped out to my van for a new fuse carrier. When I returned 2 or 3 minutes later I picked up where I had left off.
"WHACK". One hell of a belt up my right arm and across my chest and one screwdriver with the end melted. Anyone who tells you mains voltage doesn't hurt is talking crap. I was lucky. No permanent harm done.
What had gone wrong? I had been working on a dead circuit because I had isolated the main supply. However, we didn't lock off the circuits back then unless the supervisor came out on a visit. While I had nipped out to the van, the customer had decided he wanted a cup of tea so he switched the power back on. I gave him a *******in' but "sorry" is not much use after the event .
That's one lesson I'll never forget. Check it, lock it off and check it again. If you leave the room then check it on your return. Be safe mate, not sorry.
Oh, and make sure you have a decent voltage detector that also has the ability to carry out a single pole phase test.
Mike

 

[conny]

Had a similar experience many years ago also.

Changing a pendant and rose for a pensioner and left the fuse carrier, (old rewireable type), on top of the electric cupboard while I nipped back home, a few doors away, for the new pendant and rose. Came back, climbed up step ladder and got blown to the floor. She thought I had forgotten to put the fuse back in and replaced it for me!

One hard lesson to learn but one never forgotten.

 

[ericmark]

Locking off does not help. I carried two types of lock a personal lock two keys one on my ring one in Foreman's office which would only be ever used if I was off site. The other was an electricians lock all electricians on site had the key. I carried a few spare electricians locks but only one personal and also a lock clamp so multi locks could be put on same isolator.

Came to do the job and it needed more than one isolator so my lock on one and general electricians locks on the others.

General electricians lock was removed and the plant turned back on. I have never worked since. Part of my hand is now part of terminal 5 Heathrow as it was taken into a concrete recycling plant.

The problem was I was sent to do a job which was not my job to do. As a result I did not have assess to method statements for that job. Without a method statement one can't do a risk assessment. Had the fitter been doing the job he knew it required multi-locks and he had a number of personal locks.

There was also a problem in that the safety switch was black in colour. All switches for personal safety should be red or yellow and one would never remove one. Switches for machine protection only are black. As a result of wrong colour a personal safety switch had been removed to facilitate the repairs.

It does point out the problems in doing a job which is not yours to do. I had refused to do the job twice and third time it was a command and contract stated I have to do any job the management asked me to do. It was designed to stop me refusing to brush up.

I was very safety orientated doing all the right things like wearing no nylon cloths etc. But a lock is only any good if the people with the key work in a responsible manor. A hammer will remove most locks and really even a tie rap should do the job of showing some one it is intended to be switched off.

 

[westie101]

Though with safety locks we have a much stricter system, all staff that lock off have numbered personal locks with only one key, no spare, no extra kept else where just one key.
If the lock needs removed because of illness etc it has to be cut off which will only be sanctioned by a high level of management.

Further if I isolate and earth a section for work, all the keys are given with the Permit to Work to whoever is ding the work, the keys being in a locked box to which only I have the key.

 

[ericmark]

It was having just one personal lock which was the problem. Had I had 5 then system would have worked. But for job I should have been don't one lock was enough. Only when asked to do work I would not normally do did the problem arise.

Foreman was asked to tender his resignation as a result of asking or in fact telling me to do work which I was not employed to do.

 

[conny]

Where I work now they are very safety conscious.

6 initialled personal safety locks, and 6 initialled multi-locks, are issued to each engineer and a register is kept of all locks issued. If you lose one you have to report it immediately. If you leave a lock on when you go home and the job is then finished you are obliged to come back to site at your expense, (i.e. you do not get paid), and remove it. The only 2 exceptions to this rule are; a/ you have been injured during the job and been sent to hospital, and b/ you have left to go on holiday and actually set off. If you are still at home you have to come back. Anyone found removing someone else's lock, (even with their permission and key), is subject to disciplinary action which may even result in instant dismissal for both parties. As well as the locks there is a 'white board' with a marker pen which you have to hang on the machine. On the board you state your name, time of start, part of machine working on and lock initials. On completion you wipe your details clear.

There is no much more anyone can do to ensure your own safety to be honest.

 

[ericmark]

You are correct I never removed my locks. Before I was fit to return job complete.

The lock system was ample it was the doing of a job which was not mine which really was the route cause.

As with most accidents it's not one single item. Had the job been ear marked for weekend the whole plant could have been isolated with one lock. The problem was the foreman wanted it doing now and that meant doing it while part of the plant was running. Afterwards it seemed he had expected the plant to turn over to mains only water but that system was also being repaired.

He was barking orders without looking at the job first and so just did not realise what it involved.

The plant was made in Germany and designed for export so many safety features left off the plant.

 

[conny]

Sometimes we moan about H&S in this country but I think when it comes to the workplace you have to ensure all REASONABLE precautions have been taken.

Regarding your earlier comment about risk assessment, we used to have a guy who would visit the various sites and do a risk assessment & method statement. However, when we turned up we would often see things he had missed. I was instrumental in getting the company to change its policy so that the engineer(s), who would be doing the job, accompanied him and pointed out their observations. He was often amazed at some of the things he would not have picked up on.

One other vital rule we made was to check every circuit, (electrical, pneumatic and hydraulic), had been correctly isolated if the customer had claimed to have done the isolations. We would never take anyone's word for it.

 

[SimonH2]

Not my own, but a friend of mine told me this tale from years ago.

He was a general sparky back then, and had a repair to do in a cotton mill or something like. Went to the switch room, and the isolators were so old they had no lock-off facility so the best he could do was hang a "do not switch on" sign on it. Got back to the machine he was working on, tested the supply, and found it live.

Went back to the switchroom, found the isolator turned on, and the sign on the floor. Switched off again, hung up sign, went back to machine - found it live again.
Back to switchroom, found sign on floor and switch back on.

Switched off again, stood round corner and waited. Sure enough, someone came in and switched on again - at which point my mate put him on the floor.

Turned out the machines were in pairs, two to an isolator. As the operators were on piece rate, the one of the other machine wasn't going to allow anyone to interfere with his production. Once management were informed, the operator was sacked on the spot - and my mate was also escorted off site for his own safety.

With hindsight, perhaps an essential tool should be a small charge - apply power, get a good bang and smoke which might persuade people not to ignore "do not switch on" warnings


I've another mate who's got bad burn scars over most of his body (and never worked as a sparky again) - the surgeon who initially treated him didn't expect him to survive. Never did get all the details beyond "supply isolated, but genny kicked in before he touched busbars". I'm assuming it wasn't 415V because he wouldn't got the burns he did from low voltage.

 

[Spark123]

He may have got across two phases or phase and neutral/earth with something metallic, with a low impedance supply you can have one very Big Bang, explosion and molten metal flying around the place.
It is generally the current that causes this, not so much the voltage. I imagine having a short across submarine batteries, albeit only a couple of volts a piece, could result in the same.

 

[JohnW2]

It is generally the current that causes this, not so much the voltage. I imagine having a short across submarine batteries, albeit only a couple of volts a piece, could result in the same.

I was about to make a similar observation. By far the biggest 'electrical bang/explosion' I have personally ever witnessed (fortunately from a safe distance) was caused by current from a bank of 24V batteries.

Kind Regards, John

 

[bernardgreen]

One of my biggest slip ups was dropping a pair of pliers onto naked 3 phase bus bars in a generator control cabinet on board a ship. It was running on shore mains fused at ( IIRC ) 200 amps per phase.. This blacked out the ship including people working in areas totally dependent on electric light. I was NOT popular.

With hindsight I should have put some insulation over the bus bars. I was changing a meter on the front panel and had to work from the rear of the cabinet and time was short as the ship had to sail. It wasn't a big ship, more a floating tank that took the sewage slump from Beckton Sewage Works and dumped it out to sea.

This was in the days when people looked out for their own safety and did not rely on a set of rules about safety. While the rules cover foreseeable circumstances it is still up to the individual to be alert to protect themselves when the unforeseen circumstances occur.

 

[SimonH2]

I imagine having a short across submarine batteries, albeit only a couple of volts a piece, could result in the same.

Oh yes - a very large current. With a <cough> thousand amp-hour cell, there's a fair bit of oomph available. I suspect any short circuit current would be limited by the external circuit rather than the cell/battery.
As an apprentice I worked for a while in the shore battery shed - we had specially insulated tools :
Ratchet and socket all encapsulated with Paxolin or similar - so the only exposed metal was the 1/2" drive (which of course isn't exposed when the socket is in place on the ratchet) and the inside of the socket. Can't remember if we had any spanners as well.

And very fetching rubber aprons and gloves (and visors) for when handling acid. Not that it stopped my overalls taking on a very "moth eaten" appearance


I've heard a tale of someone dropping a jemmy across the busbars in a BT exchange. It glowed dark red, bright red, yellow, and finally dripped off Can't imagine he was very popular.

 

[conny]

When I worked for GEC in Liverpool two engineers went to a power station in Yorkshire to repair a distribution board. They were to work on the bus-section panel which meant one half of the board was 'dead', (the part they were working on), and the other half 'live'.

The live side was segregated by a piece of light board with 415v flowing through the busbars which were rated at 800amps. Putting pressure on a 16mm bolt head, with a 24mm open ended spanner, he braced his left hand against the cabinet casing. Suddenly the spanner slipped, his body knocked the board away and his elbow contacted the live busbars.

Result? He suffered severe burns to both arms from fingers to elbows, burns to his face resulting in loss of all facial hair, (moustache, goatee, eyebrows, eye lashes), and the hair on his head blown away to midway across his skull with severe blistering to his facial skin as well.

He managed to stagger round to the front of the panel before collapsing with shock. When his colleague was asked to describe the event he said Bobby looked like a cartoon character who had just been blown up in the face. His face was black and his hair was smoking as he came round the corner still holding a mangled spanner.

He survived but has been very badly scarred for life. As we were all made redundant before this case went to court I never found out who was to blame or if he received any compensation for his injuries.

 

[stillp]

There was also a problem in that the safety switch was black in colour. All switches for personal safety should be red or yellow and one would never remove one. Switches for machine protection only are black. As a result of wrong colour a personal safety switch had been removed to facilitate the repairs.

Not quite Eric. The red/yellow colour only indicates that the switch is intended for emergency operation.