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Old 05-22-2012, 07:24 PM   #31
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Pros: How do you feel about working around high voltage?


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In fact I would rule out commercial 3Φ wiring for the DIYer as it different enough from 2Φ residential that dangerous things could happen.
It's not 2Φ. It's single phase tapped at the transformer to create two 120v legs to neutral and 240v between legs. And it's not all that different from 3Φ, in terms of level of danger. Voltage is more a factor in danger than phases.

On another note...
The ComEd boys arrived about an hour ago. There's no "booting the line and all is well". They have to physically move the line a minimum of 10' away from where I will be working. We talked about "how it used to be" and "how it is now". Safety has taken a front seat.

It looks like they will install an ox arm, then the power lines will forever be outside that 10' diameter. I can live with that.

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Old 05-22-2012, 08:19 PM   #32
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Pros: How do you feel about working around high voltage?


I always feel a little nervous when working around high voltage, though I can't say I've ever worked in the kv range. But even opening up my electrical panel live I'm very cautious about not bumping anything and as much as it's considered safe to do so, I refuse to rack a breaker while it's live. I always shut it off, rack it, hook the wire up, then turn it back on.

I've also got a special appreciation for very high current. ex: 12v marine batteries. Every time I hook one up to something and it sparks I jump a little. While I can't really get a shock from it, doing a full short circuit by error could be disastrous.

What is interesting is walking in the battery room where I work. 48v worth of huge flooded acid batteries, not sure what the total amp capacity is, I just know that the DC amp meter shows a current draw of about 1000 amps. They are probably capable of much much more than that. Drop a wrench or something between the terminals and you are lucky if you live. If it's not the flash that kills you, it's the acid from the explosion it will surely cause. And if you do survive, you want to be dead.

I only walk around there to check that everything is good, I don't touch anything. I'm always tempted to touch the bus bar to see if I'd feel a shock though.
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Old 05-22-2012, 10:04 PM   #33
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Pros: How do you feel about working around high voltage?


I've done a fair bit of high voltage work, especially putting in cages around incoming 13.8kV. When you grab the cable and the hair on your arms stands up you know there's some serious potential in there. I've learned that complacency kills, nervousness kills, and overconfidence kills too. Best way to handle it is to give it the respect it deserves, take all necessary safety precautions but don't be scared, scared people make mistakes.
I've taken 347v through my chest way back when i was 1st term due to someone breaking the rules and pulling emergency power in with the regular power.( no one thinks to test when the powers out lol.) It's not something i care to repeat so i'm extra carefull, but i've worked with guys that shake so bad that they're an accident waiting to happen.
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Old 05-23-2012, 07:08 AM   #34
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I've taken 347v through my chest way back when i was 1st term due to someone breaking the rules and pulling emergency power in with the regular power.
I was moved to a job to help out for a few days. I knew the foreman and he was way over his head doing foreman work. He told me we had to move some 2x4 fluorescent fixtures in a suspended ceiling. Most of the tiles were out. So he gave me the prints and I went to work.

All the lighting was 277v but surely this guy would never leave cut, uncapped live wires sticking out of a box, right? So I'm up in the ceiling and sliding a fixture from one bay to the next with my right arm resting on the aluminum grid. All of the sudden the lights go out, the lights in my eyes that is. My vision starts oscillating from pitch black to light and black again. I feel the shock in my inner arm, the one resting on the grid. I'm confused. How can the grid be live? It's grounded.

Suddenly it stops. I look around me and see a cut wire sticking out of a box, right next to where my head was. I get my wiggy and sure enough, 277v. The wire touched my left temple and 277v ran through my brain and over to my right arm.

I went over to the foreman and
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Old 05-23-2012, 11:17 AM   #35
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277V and 347V are the absolute worst. Less than that and you can generally let go, more and you get blown off. Those two are the most deadly in the sense that the muscles lock up and you get "hung up" on it. Your a very luck girl.
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Old 05-24-2012, 09:44 AM   #36
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277V and 347V are the absolute worst. Less than that and you can generally let go, more and you get blown off. Those two are the most deadly in the sense that the muscles lock up and you get "hung up" on it. Your a very luck girl.
I've only been hit by 277 on one other occasion. It is truly a nasty experience. A few years after the "lights out" experience I ran into that foreman. I was a project manager at the time and he was working on a job I was looking at to estimate. He told me he got laid off from that contractor a little after I left and vowed to never again run any work. Good choice!

ComEd called this morning. Some guy who was clueless about the work. He didn't even know my address or what the situation was. I brought him up to speed and he said he'll be out to look at it today. I guess the guys who came out didn't tell him anything but probably were never even asked.

I did a drawing in the event I needed to send something to ComEd so they have an idea what needs to be done. The red is the 10' clearance radius from the 7200v line nearest the house. The green would put that line 10' from the overhang at the peak but would not allow for a person to work in front of it. They would have to cantilever those arms out quite a bit to allow for that.

Should I give this to the ComEd guy when he shows up?
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Old 05-24-2012, 05:40 PM   #37
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Every bucket I've seen in operation wobbles +/- 2' or so due to backlash/slop in the mechanism and this will subtract from your safe distances.

What's your plan if a sudden defect in the truck hydraulics drives you and your bucket right into the line or some other obstruction, with great force? There are probably pressure-sensitive interlocks to prevent this but I hope they are in working order.

Be careful. Run through every possibility first.
Show everybody every document so they cannot later say, "We didn't know." That puts them all somewhat on the hook in the event of a mishap and they will have a harder time saying, "Operator error."

With your oscillating vision I guess the current was overriding the microamp or nanoamp signals that normally flow through your brain. If the current had gone through your chest instead of your head you might have had fibrillation.
You possibly have cheated Death.

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Old 05-24-2012, 06:32 PM   #38
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Since you've done the time why don't you treat yourself and hire a painter to do the job? Maybe just bid out the high height stuff.

DIY loses its luster when you are risking personal injury.
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Old 05-24-2012, 06:46 PM   #39
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Is it even code for the utility to have a power line that close to a house? It seems rather unsafe. Especially if it falls during a storm or what not and is close enough to hit the house.
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Old 05-24-2012, 07:12 PM   #40
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They guy was out today. He measured 6.5' from the power line to the overhang on my house. He said he thought OSHA requires 7.5'. He wasn't sure about a lot of things. He was probably young enough to be my son.

They have two scenarios: (1) is they move the closer line to the top of the pole and that will put me outside the 10'. The other is someone decides to move both lines over as in the drawing I did and that might take weeks or even months to get it done.

I'll have an answer late tomorrow.

I'm going to stain that side up to 20' tomorrow. I'll be well outside the 10'.
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Old 05-25-2012, 09:18 PM   #41
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I'm done.

The scary side of the house is done. Yes, I got inside the 10' diameter. But I do remember reading OSHA requirements saying the 10' was for "inexperienced" persons.

ComEd is still going to move the wires but not for a month or more.
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Old 05-25-2012, 11:35 PM   #42
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Pros: How do you feel about working around high voltage?


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I'm done.

The scary side of the house is done. Yes, I got inside the 10' diameter. But I do remember reading OSHA requirements saying the 10' was for "inexperienced" persons.

ComEd is still going to move the wires but not for a month or more.
And you're still alive......amazing!!

Actually, with your experience and concern for safety, there was no doubt you'd do just fine.

Good work!

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