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Author Topic: Switched Neutral  (Read 1346 times)

Mike Sokol

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Re: Switched Neutral
« Reply #10 on: June 17, 2014, 07:44:19 pm »

Maybe I am not hearing/picturing this correctly?  But if I am standing in front of a mass of hot/exposed wiring, the last thing I want "protecting" me is a presumably grounded metal fence!?!
Yes, you ARE picturing it correctly. A grounded chicken wire fence right behind your back and exposed live copper bus bars in front of you. Of course, this is all gone now, but it was pretty terrifying when I saw it the first time.   

Cailen Waddell

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Re: Switched Neutral
« Reply #11 on: June 17, 2014, 08:05:24 pm »


Yes, you ARE picturing it correctly. A grounded chicken wire fence right behind your back and exposed live copper bus bars in front of you. Of course, this is all gone now, but it was pretty terrifying when I saw it the first time.

So being a lighting guy at heart (the secret is out),  I wonder if/how many arc flash accidents occurred with old resistance dimmer boards....


Sent from my iPhone using Tapatalk
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Tim McCulloch

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Re: Switched Neutral
« Reply #12 on: June 17, 2014, 11:31:05 pm »

Yes, you ARE picturing it correctly. A grounded chicken wire fence right behind your back and exposed live copper bus bars in front of you. Of course, this is all gone now, but it was pretty terrifying when I saw it the first time.

You know you're surrounded by nitwits when you see something like that and say "OMFG...." and the guy next to you asks "what's wrong?"
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Mike Sokol

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Re: Switched Neutral
« Reply #13 on: June 18, 2014, 08:57:30 am »

You know you're surrounded by nitwits when you see something like that and say "OMFG...." and the guy next to you asks "what's wrong?"

Yeah, and there was a wooden step-stool in front of the open bus-bars so the shorter operators could reach the knife switches near the top of the panel. Like it said... terrifying.

Of course, historically theaters used to use wooden tubs full of brine (salt water) with perforated metal plates inside that could be moved up and down using a broomstick to dim the electric lights. Switched neutrals seems relatively safe by those standards.

Stephen Swaffer

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Re: Switched Neutral
« Reply #14 on: June 18, 2014, 12:42:41 pm »

My dad worked on the lighting crew for theater at Bob Jones University back in the late 50's early 60's.  He has told me stories working with the open rheostats-and how they would sometimes stick especially during rapid transitions-leaving the operator the object of the directors frustration.

I am amazed at how may people open panels, etc without paying attention to their surroundings-clearances/people in the area.  Especially with live audio/lighting I would think others being around could be a major concern.  Part of the arc flash standard is setting up barriers for when you are in a live panel.  Maybe not as practical for a quick hookup, but having somebody in the area that may not be paying attention has always made me nervous.
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Jeff Bankston

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Re: Switched Neutral
« Reply #15 on: June 18, 2014, 04:27:59 pm »

My dad worked on the lighting crew for theater at Bob Jones University back in the late 50's early 60's.  He has told me stories working with the open rheostats-and how they would sometimes stick especially during rapid transitions-leaving the operator the object of the directors frustration.

I am amazed at how may people open panels, etc without paying attention to their surroundings-clearances/people in the area.  Especially with live audio/lighting I would think others being around could be a major concern.  Part of the arc flash standard is setting up barriers for when you are in a live panel.  Maybe not as practical for a quick hookup, but having somebody in the area that may not be paying attention has always made me nervous.
i am always very careful when opening panels and switch gear. guys have gotten injured and killed from covers contacting lugs and buss bars. some of the designs dont allow much clearance between stuff. even breaker panels with dead fronts need to be handle carefully. but my biggest nightmare has ben older swirch gear thats got loose screws holding it together and ready to fall apart. always open doors to switch very slowly. theres a youtube video of a guy that opened doors to quickly and stired up dust with moisture and he got lit up. a security camera recorded it.
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Steve M Smith

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Re: Switched Neutral
« Reply #16 on: June 18, 2014, 05:44:00 pm »

Yes, you ARE picturing it correctly. A grounded chicken wire fence right behind your back and exposed live copper bus bars in front of you.

Someone actually bothered to ground it?


Steve.
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Lyle Williams

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Re: Switched Neutral
« Reply #17 on: June 19, 2014, 05:33:32 am »

Someone actually bothered to ground it?


Steve.

Maybe they knew what they were doing.  Mr McCoy making things nice and safe at the Hatfield Theatre.  :-)

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Mike Sokol

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Re: Switched Neutral
« Reply #18 on: June 19, 2014, 06:55:12 am »

Maybe they knew what they were doing.  Mr McCoy making things nice and safe at the Hatfield Theatre.  :-)

Well, I can't be sure it was grounded, so who knows. But I'm sure the exposed copper bus bars were hot.  ::)

I was a young engineering pup in my 20's doing sound for a rock band at this theater, so I didn't touch the lighting (lucky for me). I just remember seeing this crazy rig and asking about this new fence. They said it was obviously so that nobody pushed the lighting operator into the open circuits. I've got to wonder if there was an incident that made them build the chicken wire wall? Also, this was in the early 70's around the time I was getting OSHA certified at my day job, and OSHA was a baby industry at the time starting in 1970 IIRC. So all the power they had at the time was to recommend a chicken wire fence around the deadly lighting controller. Boy how things have changed...

Jonathan Johnson

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Re: Switched Neutral
« Reply #19 on: June 19, 2014, 12:17:49 pm »

I've got to wonder if there was an incident that made them build the chicken wire wall?

Fried chicken. Mmmmm.
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