FYI

http://www.wsbtv.com/news/15114483/detail.html

Around here a school custodian isn't allowed do do any electrical repairs other than changing lamps and resetting circuit breakers. This especially in some of the newer schools as they most likely have 347V lighting circuits. They are not qualified and its simply too dangerous.

A.D

Many qualified electricians have been killed doing the same thing.

That is true BUT as qualified electricians we should know the safe way of doing electrical repairs and practice them on the job. There is no reason an electrician should get electrocuted.

A.D

You are right, if OSHA rules would have been followed and the basic rule of "NO HOT WORK" would have been observed, this man would have gone home to his family and a long life.

Roger

I suppose we can always play 'what if.' Let's face reality, though: the safety and convenience of a maintenance worker years later is WAY down on the list of design criteria. Sometimes I think we design lighting to make sure that the ballasts are changed 'hot.'

Economy is high on the list of priorities. Use 277 rather than 120, and you need far fewer circuits. You also make it lots easier to kill someone.

Central management is a high priority, where all lighting circuits get shuffled through a contactor, and a remote controller, in some inaccessible place. There goes the local light switch at every door!

Energy management ... ahh, yes ... now you often have TWO ways to fry when you change a ballast. Split fixtures might look nice, but you still are presenting the guy with a choice of either placing everyone in the dark, or working hot.

Emergency lighting ... ever try to turn one off? Now, there's some competition for the PoCo ... there's a battery that wants to zap you as well!

When I build my mansion up at Lake Tahoe, I think I'll just use keyless fixtures, with pull chains and CFL's

A.D. I guarantee you highly qualified electricians have been killed on the job. Mistakes happen, sometime the mistake was made long ago and the qualified guy who comes along today gets bit buy the old mistake.

Iwire: I have to say I fully agree with mistakes in the past coming back to haunt us in the future.. Believe me I have seen some interesting things done by people in the past that could have been deadly.. I guess that is why I tend to lean towards electrical repairs only being done by qualified people as well. Yes we all can make a mistake as we are human but the qualified person is less likely to do something where it could be lethal to themselves or someone in the future, versus someone that hasn't a clue or a at best some general electrical knowledge and experience. God knows I could go on about one of the supers in the ex-girlfriends apartment complex taking it upon himself to do electrical repairs without any knowledge whatsoever and causing at minimum a "minor inconvience" all the way up to a full out blackout local to some areas of the buildings!

Reno: I also hear what you are saying in regards to almost being forced to change ballasts and such "hot".. Agreed I have done it, it was a 347V fixture, and I know I shouldn't have but it was an issue of " Do I black out the whole store to do this or do I take extra precautions".. On went the gloves and up I went on the fiberglass ladder... I will note that the code has changed here in Canada where all 347V+ fixtures are required to have "disconnects" wired into them and I did wire one into the fixture and each subsequent fixture I repaired, not so much for my safety but for the next guy down the road that may have to change out this ballast a decade from now. Agreed these little disconnects are pricey little things but better safe than sorry correct?
The thing that really puzzles me is Canadian code requires them in all 347V+ fixtures ( yes there is the rare 600V fixture). I figure why not make them manditory for ALL fixtures regardless of voltage?!

Sorry for rambling on but 'ya know, just my $0.02 worth!

A.D

No, Rewired, you're not rambling. Not to my ears, anyway.

Nor should anyone get the idea that I was belittling the risks of 'working hot.' Quite the opposite. In case anyone was missing my point, I was being quite critical of poor design, which I believe creates (or encourages) unsafe situations.

It's long past time for ballasts to be made to "plug in," and not put us in the position of working with hot wires. Unfortunately (as discussed elsewhere) I believe the current version of this 'solution' is no improvement at all.

What's the real source of the problem? IMO, perception. It's natural to equate 'small' with 'harmless.' Ever notice just how careful we are with 'high' voltage, 'large' amps, and 'big wire?' Why, there just can't be any real danger in those tiny wires! WRONG!

When I saw a guy get electrocuted (he was revived), it was less than 20 amps of 120 on a #12 wire. Many of the 'light ballast electrocutions' involve 277 volts. It's those tiny wires that seem to get you every time!

I can vividly remember a similar instance when I was in 3rd grade in my own classroom. Funny how certain things stick with you. The fellow was not seriously hurt anyway. He was changing out a once of those synced clocks that went "ca-thunk" every minute. I dont know the specifics, but I recall the sparks shooting out of the box on the wall while he had his hand in there and him falling off his ladder. Startled us all pretty good, but he got back up and assured us he was OK before leaving the room.

I know that as a homeowner in this state I can legally change my own light fixtures and switches without having to call an electrician. But once it becomes your job or you do it for pay for other people I thought that a license or something was necessary. Shouldn't the school be held accountable for asking him to do something that should not legally have been part of his job?

I actually have a new ballast sitting downstairs right now waiting to go into a failing garage light. There is nothing dangerous about changing them as long as you turn the power off!

as far as plugs, yes, that would be great, but adding a few more pennies to the manufacturing cost of something wont happen unless it's required to happen unfortunately.

I know that 347V is a Canadian thing, but do you also have 277V lighting fixtures up there or just go straight from 120 to 347?

Over here everything is 240V to ground, which can pack enough of a punch. (They're not something I ever have to work on, but there are also triple fluoro fittings which are run from 3-phase, thus putting 415V in the fixture.)

HSE (Health & Safety Executive -- our equivalent of OSHA) has become very critical about any sort of live work in recent years.

Actually IMHO, what kills and injures professional electricians is complacency.
The old idea that you've done all this before, can get you in real trouble.
I happened to be reading the latest release of Electrical accidents published by our electrical safety authority here and the stats don't make for good reading from an actual safety point of view, 85% of all electrical accidents in the trade were caused by "Failure to isolate live equipment" and "Failure to test for presence of voltage after isolation"
3 electricians lost their lives in a 6 month period because of these basic things.
Sure I have worked live before, but I only do it when there is no other alternative and that would be a pretty rare occurence, there is no need to work live if you don't have to, it doesn't make you a "cut above" any other electrician, that doesn't.
It's all about coming home from work with the same things you went to work with.

Pauluk:
277 volt fixtures here are rare but they do exist... Often its a case where a building contains a lot of machinery designed for use in the U.S.A and a 277Y / 480V supply is used. (The PoCo will NOT supply this , you must step 600V down to 277Y / 480 yourself). There are only two buildings I know of in the area that use this system as well and I will make mention there is one other building in this city that has a "240Y 416V" system in it.. VERY rare in Canada and why it was done I do not know but the 240V electric heating we installed was connected to this system and was all connected line-neutral which is a bit bizarre for us Canucks, as 240V is usually a line-line voltage!
This brings be back to some of the different lighting voltages we have here for lighting .. We do have some H.I.D stuff in parking lots that is sometimes "208V" or "240V" and it works fine and is safe because these voltages originate from supplies that are 120V to ground. The catch with that is with standard autotransformer type H.I.D ballasts whereby one side of the line is connected to the appropriate ballast "tap" and the other is connected to the ballast "Common" lead which is also connected to the metal screw-shell of the lamp... See the problem here? Should someone decide to change a lamp in a live fixture wired 208V or 240V and they happen to touch the screw-shell of the lamp and ground while doing so, blammo they get a 120V shock.
We also have 600V lighting as well but again this is rare and generally its found in the steel mills where the system originates from a 600V ungrounded delta supply
(according to my Father), and the ballasts for these are "isolation" type, so no real chance of touching the screwshell of a bulb and getting a 347V blast..

My highschool was another oddity that had 600V fluorescent lighting in 1/2 the building, only because the half that contained this lighting also contained all the machine / welding, wood, electrical,and auto shops as well as the boilers and all its related equipment,all of which was 600V, and in 1963 when the place was built I don't think 347V lighting even existed let alone a 347Y/600V service being availible from the PoCo, although it may have originated from a grounded Y secondary, no neutral was present as far as I can remember.

A.D

In my area (New England), for other than dwelling units 277 lighting is far and away the most common voltage for lighting circuits.

If it's a commercial building (unless it is small) the service will be 480Y/277.

Outdoor lighting is often run line to line at 480 volt.

It seems like I hear too many people getting either electrocuted or knocked off their ladder by lights.... all because someone didn't hit the disconnect or the "manager" of the place didn't want the lights out.

I got a better idea.... use a system similar to the old tube radios: an interlock plug or switch. If you remove the lamp cover, the ballast terminals become de energized and the always on terminals are insulated well. This way bulbs, sockets and even the ballast itself could be safely changed without being exposed to live conductors. The switch would likely not need servicing for the life of the fixture, so it would be rarely messed with.

The other way would be an intermittent duty manually actuated switch (its not used all the time so it can be kinda cheap.) or a plug that you pull that contains a jumper. The input to the jumper block or switch is recessed so it wont easily be touched and the output terminals are accessible only once the jumper block has been removed or in the case of the switch, a cover moves out of the way of the terminals once it is slid to the open position.

Ya thats kind of what we are using now, a "plug" type of device that resembles those "weatherpack" type of connectors you see on almost every north american automobile .. The nice thing about this setup is it disconnects hot AND neutral to the ballast. You are now safe from the hot conductor AND from having to mess with a neutral that may be part of a multi- wire circuit feeding other lights in the row, or from getting a belt off the neutral should there be something amiss elsewhere in the building's wiring.

A.D

In the UK under the Electricity at Work Regulations and Health and Safety at Work Act NO live working is allowed unless it has been deemed impracticable then method statements and risk assessment for safe working comes into play. If he had been in this country and he had survived he would have found himself being investigated by the Health & Safety Executive and then found himself being procecuted for breach of the above regs/act.

And that is one of the typically vague sort of requirements that keeps lawyers in business. Who decides what should be deemed impractical?

I'm all for working as safely as possible, but to be honest the U.K. is getting absolutely carried away with this risk assessment stuff. Most of the bureaucrats sitting in their ivory towers making these rules also have absolutely no practical experience themselves.