PSA- electrical safety

Well, I just got home after spending nine hours in the ED. Bottom line, if you are going to be messing with anything electrical, be safe!

I've been an electrician for ten years, and have worked on some pretty scary stuff. But I made it through unscathed, because I and the folks I was working with were smart about it and took nothing for granted.

Today at work my tool partner and I were trying to chase down a lighting circuit. I was in a room on a ladder, in the ceiling (not the best light) and took a cover off of a junction box to look inside. Something I've done countless times, and the worst that has happened in my experience is a wire nut pops of and sparks get made. After taking the cover off I reached up and touched the box with my hand, had my other hand on the top of a steel door. Evidently there were some burned conductors in there I didn't see, and by removing the cover it caused them to touch the side of the metal box. When I touched the box I became the infamous Rex Resistor, and quickly found myself on the floor in pain.

One simple thing I've done many, many times, and took for granted bit me from finger tip to finger tip right through my chest.

Scary E36 M3.

Long story short, no apparent damage done to my insides thank God. And I'll have a day at home to spend with my kids and think about what happened.

Don't ever take anything electrical for granted- from a car battery to a 480/277 volt lighting circuit.

I had our "safety" jerk off at one job tell me to wrap a plastic bag around a sparking 1900 box. I hose down the room every night to clean it. I stand in water. I ain't touching it. Things don't spark unless they're BROKEN you dolt!

I come to learn that it was 220, 3 phase on a 60 amp buss. That will straight up kill you , and it will hurt the entire time you are dying.

Never listened to him again.

Glad to hear that neither the electricity nor the gravity could take you.

Scary stuff man! Industrial electricity is serious business. Most of us have gotten a little zap from a 110 circuit and just been rattled. What you got into is on a whole other level of danger. Glad you're still with us!

That sucks when a box isn't grounded properly. I am glad I have a high skin resistance. A 277VAC shock is only annoying for me.

Thanks for the reminder. I have bad habits sometimes. Glad you are OK.

pjbgravely wrote: That sucks when a box isn't grounded properly. I am glad I have a high skin resistance. A 277VAC shock is only annoying for me.

Who said anything about the box not being grounded properly?

The worst shock I have ever had in my 20+ year in the trade was a very similar situation. That 277VAC stuff really hurts! I let out an uncontrollable scream when I caught me, and I have no idea how I didn't fall off the ladder.

Glad to hear your okay. My biggest worry in the trade now is arc fault as I wasn't really aware of the dangers until taking training for it. All these years we never knew how dangerous arc fault was/is. I wear my suit now.

I watched a young electrician get killed on a jobsite in Tampa. Somehow grabbed a live 440 line, it blew him off the scaffold, fell 20'. That memory stays with you. I was 20' away, he never made a sound.

Glad you are here to tell us about dangerous things yourself instead of reading a news clipping.

Dang man, I'm glad you're okay.

So if the box was grounded, would it have prevented the problem? (How could burned conductors touching a metal box not trip a breaker?)

I spend time in dropped ceilings some times, and it's not fun. Also deal with poorly installed wire nuts from time to time, double not fun.

Ouch. Glad you are OK.

pjbgravely wrote: That sucks when a box isn't grounded properly. I am glad I have a high skin resistance. A 277VAC shock is only annoying for me.

Indeed the box was not grounded. The building I was in was built in the late 70s or early 80s when a different set of rules was in place. Part of our project is to bring things up to current code as we work through.

We are dealing with lighting, so almost by default (for us) this means 277v and shared neutrals- both red flags.

Because there wasn't a grounding conductor installed, the only path the curcuit had to ground was the raceway from the panel. More than likely that path isn't complete, so high impedance, so the breaker sees it as a load, not a fault.

The grounding conductor provides a low impedance path to ground so the breaker will trip straight away.

I suspect the phase conductor got me, but I won't know until tomorrow when I go back to fix it.

Luckily this is is an AC system, so I got out of it. DC systems don't let go.

Mazdax605 wrote:

pjbgravely wrote: That sucks when a box isn't grounded properly. I am glad I have a high skin resistance. A 277VAC shock is only annoying for me.

Who said anything about the box not being grounded properly? The worst shock I have ever had in my 20+ year in the trade was a very similar situation. That 277VAC stuff really hurts! I let out an uncontrollable scream when I caught me, and I have no idea how I didn't fall off the ladder. Glad to hear your okay. My biggest worry in the trade now is arc fault as I wasn't really aware of the dangers until taking training for it. All these years we never knew how dangerous arc fault was/is. I wear my suit now.

This for sure! I'm glad you wear the suit. Arc incidents are a whole different world of scary! As if being shocked isn't scary enough, imagine having your face and arms being burned off while it happens!

Glad you're okay. I worked with a guy who stopped being an industrial electrician after his partner at the time had a leg blown off from a 640 (or whatever's close) arc flash.

Glad you are ok! Electricity can be a real jerk sometimes, and we all need to be careful.

I've learned my lesson as well. About 10 years ago, I was working on my Trans Am, and was adjusting timing while it was running. I went to bump the distributor over, and put my hand on the top of the distributor to move it. BAD IDEA. My hand locked onto it, and I couldn't move! And it HURT! Luckily, my dad was nearby, saw what happened, and knocked me off the car after I muttered "Help!"

I know this sounds strange, but ever since then, I feel like I almost have a hypersensitivity toward electricity, especially thunderstorms and lightning. It's like I can feel when they are coming, and when they are going to hit. It's so weird.

I've been shocked a lot (by 120vac, high-voltage capacitors with small charges, or ignition coils) and know what you mean. I think it's mostly a familiarity with the feeling of voltage hitting you - the air gets ionized during thunderstorms so you can feel the electric potential. It's possible for someone that hasn't been shocked to feel it if they know what to look for. I think. Either that or we're nuts.

You got lucky. My grandfather was killed because a sparky screwed up wiring an outlet at job site back in the 1950s. It was only 220v but it got him just right.

Thanks for the timely reminder, I'm moving Power points and light switches about at the moment. Whilst I'm always careful, you remind that being extra careful is well worth it.

Good to hear you're ok.

paranoid_android74 wrote: Indeed the box was not grounded. The building I was in was built in the late 70s or early 80s when a different set of rules was in place. Part of our project is to bring things up to current code as we work through. We are dealing with lighting, so almost by default (for us) this means 277v and shared neutrals- both red flags.Because there wasn't a grounding conductor installed, the only path the curcuit had to ground was the raceway from the panel. More than likely that path isn't complete, so high impedance, so the breaker sees it as a load, not a fault. The grounding conductor provides a low impedance path to ground so the breaker will trip straight away. I suspect the phase conductor got me, but I won't know until tomorrow when I go back to fix it. Luckily this is is an AC system, so I got out of it. DC systems don't let go.

I remember those days, renovating nightmare electrical systems. I am lucky now, brand new building. I don't even have to worry about shared neutrals or ungrounded pipes or boxes for a while.

The worst shock I ever got was when a sign ballast wire decided to leave its splice block and in-bed into my arm.

The second worst was a shared neutral on 277. I haven't had the pleasure of working on DC. My next project involves a 400VDC generator that I will have to be very careful of.

In reply to pjbgravely:

Speaking of 400 volts, I got a dose of that back in the day, when performing a gun firing circuit test on an F-16. I found the short-to-ground in the Cannon plug the hard way when dip-E36 M3 in the cockpit squeezed the trigger again after re-setting a circuit breaker and not informing me of the fact that he was about to squeeze the trigger a second time... My left arm went numb and my scalp tingled for hours.

I'm really sorry, I forgot to say thank you for all the well wishes!

pjbgravely: This system was renovated and "fixed" not long ago. Rather than go through the wiring and separate the neutrals, they put the phase conductors sharing the neutral on one three pole breaker. Problem was solved, except where the neutral was shared on a circuit on another three pole breaker.

In another department I had to take care of five wet cell battery strings. 240 cells at 2.5 volts per cell connected in series made up one string. That's roughly 600 volts DC at the end. Interestingly in those strings, the voltage to ground increases as you move further up the string. I got zinged (just my hand to my elbow) at about the 400 volt point.

I have never encountered a DC generator. Very interesting!

glad you are ok... Electricity is the one thing I take no chances with. Working as a stage electrician (and usually as the deck electrician when any shows come in) I deal with 5 (five!) boxes with 3 phase 400 amp service. I have stopped many a person who should know better from trying to disconnect hot by grabbing the ground first.

I work with electric forklifts, along with batteries and chargers. Minor DC zaps are part of the business, but good safety habits and knowledge of hazards keep techs safe.

When I was pretty new in the business I was shocked by a faulty battery charger. I don't think I got the full 480vac, but I got enough to not want to feel it again.

It was a 3phz unit, and I think it was shorting to the cabinet through a faulty transformer. Some of these charger cabinets get so much dirt built up in them that I wouldn't be surprised if the dirt caused the short.

Anyway, I wasn't actually working on this unit, it was a sweltering hot summer day, and I was drenched in sweat. I leaned against the case of this charger while I was working on something else. At first I thought I got stung by a wasp, then I knew it wasn't a wasp when my whole leg felt it. Obviously there was also a problem with the grounding of the case as well. The customer didn't seem to care.

Sadly, I've come across quite a few chargers that didn't have the ground wire connected, or worse yet, connected inside the case, but not connected at the local disconnect!

I once got a pretty decent burn from what I have to admit was nobody's fault but mine. I was trouble shooting a charger in a battery of chargers, most of which were in use. I was very careful to cut the AC power to the correct unit, but didn't double check that there wasn't a battery connected to the DC output cables. With so many batteries, chargers and cables all in the same place, it was easy to loose track of what was connected to what. I'll never make that mistake again. I can still smell the burnt flesh from my finger just thinking about it.