Standing on a ladder -- would I get shocked?

If I were to stand on a large ladder that had very thick plastic shoes at the base and climbed to the top of it and touched the hot wire of a light fixture, would I receive a shock? I only touch the hot wire and the ladder is only touching the ground via the thick plastic shoes.

Thanks!

Reply to
aphexcoil
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If it's a metal ladder don't do it. You might only get a little buzz but if you fall off the ladder it doesn't matter. Better is to power down the circuit before you open the box, metal ladder or not.

Reply to
Greg

the question you always need to ask is: what happens if I'm wrong?

large ladder, small shock, muscles spasm, thrown clear of ladder, body weight lands above head, and as happens in all those cases above roughly 7 feet, head vessels rupture and death within a minute or so..

And on the other hand, if you're right, you don't need to turn off the power.

Am I getting in the way of the thinning of the herd and the improvement of the species, or am I helping a person who asked so he wouldn't get thinned? We'll never know - ya gotta do what ya gotta do.

Reply to
Hobdbcgv

I remember having to do a similar thing whilst working for an AM radio station some years back.

Whenever we needed to change the tower lighting globes we would place a rather long wooden step-ladder up against the side of the tower, take off all metal objects (rings, watches, etc.), climb up the ladder as far as possible and grab onto the tower rungs with both hands at once (the tower being live at the time, of course). Once inside the tower you were okay, but getting back out was harder. If you mistimed your grab, you could get a nasty RF burn that would take weeks to heal.

Sometimes there isn't really any other way to do it. ;-)

Cameron:-)

Reply to
Cameron Dorrough

Thanks for your concern. This was purely a hypothetical question that was brought on by watching a seasoned electrician change fluorescent light fixtures with the power still on.

I asked him, "You work with wires live?"

He basically said that although the ladder was metallic, the shoes on the ladder were electrically insulated for up to 500 volts or so and that there was no danger of him getting shocked so long as he never touched the hot and a neutral or the metal fixture, etc.

I just thought it was interesting that you could grab hold of hot and not feel anything. I guess if I stood on a plastic milk crate and touched hot it would be a safer experiment to see for myself.

Thanks!

Reply to
aphexcoil

YES.

Reply to
Ben Miller

He certainly is a trusting soul. I have never seen an electrician on a metal ladder. They use Fiberglass. There are just too many ways a metal ladder can get grounded.

Reply to
Greg

A small shock perhaps.. but one large enough to throw you? I, for one, am not convinced..

After all, if that were true, all them little critters that run up wooden power poles, cross the insulators, and race out across the wires would get thrown to the ground - or at least get enough of a tingle to stop in their tracks and think twice. Or are people different somehow?

Cameron:-)

Reply to
Cameron Dorrough

A charging current shock? I don't see how if the situation is perfectly as I described and there is no way for the current to get to ground?

Why yes?

Reply to
aphexcoil

The problem is electricians don't work in a vacuum. There are other trades working around them, dragging things past the ladder. If the metal framer happens to lay a steel stud next to the ladder and the other end is laying on a framing member that is shot pinned in, you have a path. If there is a grounded power tool that gets laid oon the ladder you have a path. If the rubber feet wear down and the rivets touch the concrete floor you have a path. Your helper could be grounded when he grabs the ladder creating a path for both of you. For that matter the electrician could put the ladder down on a piece of metal that pierces the rubber foot. I agree that if you are in the middle of a clean room, nobody else around and you are careful about never being grounded and careful about maintaining your ladder you *might* never feel a shock but that is not how it works in the real world. That's why OSHA won't let electricians have metal ladders.

Reply to
Greg

Certainly you can get shocked. You could even get electrocuted. There is a capacity between you and the ground, no matter how well insullated you are. In fact the Insulation can act as a dielectric increasing the capacity between you and ground. I blew out a $500 dollar speaker with the power turned off. I connected one speaker wire to the audio output and the other brushed against the chassy.There was a capacitor to ground and to the high side,. and enough current flowed to blow the speaker with the power turned off.

When working with power, it is always best to not only turn the power off but disconnect to be sure.

This is not to mention the rf that may be on the wire if it is acting as an antenna which some one pointed out. You could be a fine ground, through capacity for that "RF. . . I DO NOT FOLLOW MANY OF THESE NEWS GROUPS To answere me address mail to snipped-for-privacy@aol.com

Reply to
BUSHBADEE

Back in the old maintenance days, we changed fluorescent ballasts live from a man-lift or sometimes a fiberglass ladder. We found that a bigger hazard than shock was connecting a 277v ballast live that had a dead short (like the wire was pinched under the ballast when it was installed.) Most of the lighting circuits were on 30a or 60a bus plugs and could make a pretty big flash and boom...the older electricians held the wire junction close so they could see it.

Reply to
Steve Cothran

Because I don't know anything about the ladder materials, the plastic feet material (is it dielectric?), is the ladder wet or dry, other nearby metal, what else are you holding, etc. And I don't know if this was a hypothetical from someone with electrical knowledge, or something that you might be planning to try, with no electrical knowledge.

Hypothetically, if you are perfectly insulated from any conductive ground path, which includes not touching any other part of the fixture, then you won't get a shock (Although technically, you could still feel a very slight tingle just due to capacitive current, but this would be an extremely low level).

From a practical standpoint, do not test this theory. Kill the power first.

Ben Miller

Reply to
Ben Miller

About ladders and shocking experiences: although there are lots of ways to not getg shocked, the most common way to get zapped significantly is to use a metal ladder and touch something you thought was grounded but wasn't.

Think of the scenerio for a minute -- ladder on dirt, you with one hand holding a rung, and the other touching a fixture that's at 120 V.

Now, if you add in other factors -- ladder on a non-conductive surface, dry wooden ladder, and so on, you may not, in touching an electrically live surface, complete a circuit. However, turn the power off! In an emergency one can wear insulating gloves or take other percautions, but the prudent thing is to turn the power off.

Reply to
tony

I you are in the US, invest in some rudimentary 29CFR1910.331-.335 training, and then come back and explain it in terms you've learned..

--s falke

Reply to
s falke

There is a rule I remember from the safety class I took some 10 years ago (easy to remember): When you do some work following 4 steps will keep you safe:

  1. IDENTIFY (figure out what is what)
  2. ISOLATE (shut off the power, "visible open" is more reliable than switch in "off" position).
  3. TEST (check if it is really off)
  4. GROUND (short it to reliable ground)

I would isolate myself from the ground too (with fiberglass ladder mentioned below)

Reply to
Michael

On 12/12/2003 "aphexcoil" opined:-

If there were no damp on the plastic, it were similarly insulated from the wall it was leaning upon and further assuming that the plastic were non-conducting, then you would not receive a shock from normal mains voltage via the ladder at least.

Reply to
Harry Bloomfield

"aphexcoil" wrote on 12/12/2003 :-

I don't think he would have been changing the fixtures live, only the tubes perhaps? Changing lamps and tubes it is usually quicker and easier to do this live. Doing such live and holding the tube would not involve touching live (hot) parts if one takes just a little care. Much of the fault finding proceedure also has to be done live.

That is fine and no shock would be possible provided he did not accidently touch ground or neutral. Were I working on live equipment on a metal ladder which was insulated at the ends, I would be concerned about the potential risk of someone passing to touch the ladder and give us both a shock. In such circumstances I would ensure there was someone to ensure no one did touch the ladder.

In a different thread someone mentioned you would recive a shock as you and the item you were standing upon is charged up to mains potential. This is absolute rubbish. In order for something to charge up, the items you were in contact with would have to comprise a very large surface area and be closely spaced to the opposite polarity (the ground). DC is much, much worse in this respect than AC mains.

Some things can be charged up, I have known cable cores when tested with high voltage DC charge up when the cable length is extremely long, the insulation extremely good and the conditions very dry. Remove the cgharging potential and you can stil receive a shock from the cable end.

If you were considering such a death defying experiment, then please ensure you do it in the presence of and under the supervision of someone qualified.

Standing on such a crate, you would need to ensure your fingers and body only contacted the live wire alone, not the neutral or metal covers, or the wall.

It is potentially a very dangerous stunt if you are not absolutely certain of what you are doing, none the less those with experience can do this as part of their daily routine and quite safely get away with it. I can and do.

Just to give you some idea....

132Kv (that's 132 thousand volt) linesmen often carry out repairs on live lines. One system dangles the worker from an helicoptor with the worker quite safely touching the live cable. Birds can and do safely land on live lines.
Reply to
Harry Bloomfield

true - no one has ever been electrocuted if they don't touch a live source or a neutral-with -voltage while touching a return -ground or neutral.

However, there are many who thought it wasn't live or there wasn't a return and are no longer here. Most who aren't here thought there wasn't a path, actually.

And on a personal note - the stuff is out to get you - one that comes to mind is the "too-cool" guy (not me) on the cage who did the old 460 volt casual backhand sweep to check for 460 hot - it was a 5K line. He was not dead, just some nasty 3rd degree burns on his hand and leg as it blew thru his clothes going to ground And the personal ones that keep me paranoid-

1) the d___ metal cases/frame that have a short that isn't enough to blow a fuse or trip a breaker and is grounded by the part being removed. Pinch a hot in the metal door or clamp so the insulation is crushed almost thru and see what happens - enough leakage across the insulation to sting pretty well. 2) or drop a bare 460 single phase lead onto a metal frame at the end of a 1000 foot shielded line and be amazed that the 30 amp fuse at the other (box) end does not blow as the end welds to the frame. (The other engineer was apparently not aware that a 30 amp fuse is not the same as a 30 amp low energy let-thru fuse -I did a change out to very-low-energy let thru fuses -both ends, with signage - that day.) 3) And helpful workmanship - I was stung hard on a completely ground-connected metal-to-earth machine, with grounded plug and the whole nine yards, because someone removed a box ground to fix their problem and saw that nothing happened, so they left it off. Worked fine for months - until.... - on a small crane, small dia wire rope - when I pulled the pin and lifted the steel rope's connector off the steel eye, and opened "the other ground" - bam! Fortunately for me, I was paranoid and knew it could be a ground, so as well as following the usual protocols of tie-off, etc., during the training of some workers, I did the one hand only, second foot hooked under rail, other hand away from metal on fiber lanyard of harness, and even then I took a hard sting thru the gloves, 600 feet up. A worker using usual procedures would have been knocked out and/or into his harness.

So, my question has been - what if you are wrong?

And - have I ever knowingly changed out a hot fixture? yes, a couple times across the years - but never if I could turn off power, and always with more levels of protection than I could count.

Reply to
Hobdbcgv

Maybe, maybe not. But you will when someone else walks by and touches the ladder. The shock may not kill either of you, but you will die from the fall and the other person will die when you land on him.

Reply to
Paul Hovnanian P.E.

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