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Author Topic: Electrical Code Compliance  (Read 7916 times)

Mike Sokol

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Electrical Code Compliance
« on: January 23, 2014, 07:45:11 am »

Why do "qualified" people need to be warned that an arc flash hazard exists inside an electrical panel?  Shouldn't that be a crucial part of their "qualification"?

From Mike Holt's NEC Q&A Newsletter. Note that the 2014 code includes egress door and panic hardware requirements around service panels which eliminates door knobs that require grasping action to use. They seem to be taking arc-flash very seriously. Also note that the electrical contractor can be held liable if these "non-electrical" egress door code requirements are not met.

Q3. What are the NEC requirements for entrance and egress from electrical equipment working spaces?

A3. At least one entrance of sufficient area must provide access to and egress from the working space [110.26(C)(1)].
 
An entrance to and egress from each end of the working space of electrical equipment rated 1,200A or more that’s over 6 ft wide is required. The opening must be a minimum of 24 in. wide and 6˝ ft high. A single entrance to and egress from the required working space is permitted where either of the following conditions is met [110.26(C)(2)]:

Only one entrance is required where the location permits a continuous and unobstructed way of egress travel [110.26(C)(2)(a)].

Only one entrance is required where the required working space depth is doubled, and the equipment is located so the edge of the entrance is no closer than the required working space distance [110.26(C)(2)(b).

If equipment with overcurrent or switching devices rated 800A or more is installed, personnel door(s) for entrance to and egress from the working space located less than 25 ft from the nearest edge of the working space must have the door(s) open in the direction of egress and be equipped with listed panic hardware  [110.26(C)(3).

Author’s Comment:

History has shown that electricians who suffer burns on their hands in electrical arc flash or arc blast events often can’t open doors equipped with knobs that must be turned.

Since this requirement is in the NEC, the electrical contractor is responsible for ensuring that panic hardware is installed where required. Some electrical contractors are offended at being held liable for nonelectrical responsibilities, but this rule is designed to save the lives of electricians. For this and other reasons, many construction professionals routinely hold “pre-construction” or “pre-con” meetings to review potential opportunities for miscommunication—before the work begins.

« Last Edit: January 23, 2014, 07:54:24 am by Mike Sokol »
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Tim McCulloch

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Re: Electrical Code Compliance
« Reply #1 on: January 23, 2014, 01:24:44 pm »

From Mike Holt's NEC Q&A Newsletter. Note that the 2014 code includes egress door and panic hardware requirements around service panels which eliminates door knobs that require grasping action to use. They seem to be taking arc-flash very seriously. Also note that the electrical contractor can be held liable if these "non-electrical" egress door code requirements are not met.

Q3. What are the NEC requirements for entrance and egress from electrical equipment working spaces?

A3. At least one entrance of sufficient area must provide access to and egress from the working space [110.26(C)(1)].
 
An entrance to and egress from each end of the working space of electrical equipment rated 1,200A or more that’s over 6 ft wide is required. The opening must be a minimum of 24 in. wide and 6˝ ft high. A single entrance to and egress from the required working space is permitted where either of the following conditions is met [110.26(C)(2)]:

Only one entrance is required where the location permits a continuous and unobstructed way of egress travel [110.26(C)(2)(a)].

Only one entrance is required where the required working space depth is doubled, and the equipment is located so the edge of the entrance is no closer than the required working space distance [110.26(C)(2)(b).

If equipment with overcurrent or switching devices rated 800A or more is installed, personnel door(s) for entrance to and egress from the working space located less than 25 ft from the nearest edge of the working space must have the door(s) open in the direction of egress and be equipped with listed panic hardware  [110.26(C)(3).

Author’s Comment:

History has shown that electricians who suffer burns on their hands in electrical arc flash or arc blast events often can’t open doors equipped with knobs that must be turned.

Since this requirement is in the NEC, the electrical contractor is responsible for ensuring that panic hardware is installed where required. Some electrical contractors are offended at being held liable for nonelectrical responsibilities, but this rule is designed to save the lives of electricians. For this and other reasons, many construction professionals routinely hold “pre-construction” or “pre-con” meetings to review potential opportunities for miscommunication—before the work begins.


Mike, thanks for the references.

Our county arena is beginning its 5th year of operation, so the design is roughly 7 years old (NEC 2005?).  The doors on the SL/SR power vaults do open outward, but have lever-type hardware, hydraulic door closers, etc.  I can see the virtue of panic bars.  The vault contains the 480 delta/208 wye transformer, the company switches and Posi-Lok panels.  4 400 amp 120/208v services and 4 200 amp 120/208v services per vault.

The breakers that feed the company switches and Posi-Loks are located on the opposite wall, and next to the exit (at SR, SL is different, the breakers are furthest from the door).  We don't hook up to, or work inside any live box.  Feeder comes in via 8"x16" mouse holes, under the panels and switches - nothing crosses the egress path.

Just thinking out loud here...  Thanks for the mind jog, I need to talk to our other arena electricians about a couple of of things.

Tim Mc

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Mike Sokol

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Re: Electrical Code Compliance
« Reply #2 on: January 23, 2014, 02:07:11 pm »

The breakers that feed the company switches and Posi-Loks are located on the opposite wall, and next to the exit (at SR, SL is different, the breakers are furthest from the door).  We don't hook up to, or work inside any live box.  Feeder comes in via 8"x16" mouse holes, under the panels and switches - nothing crosses the egress path.

I believe that at some point there WILL be an electrician opening up a live box in your facility, and it's exactly THAT electrician who need to have the panic bars on the door in case something goes wrong while he's inside your live panel changing a circuit breaker or whatever. Now that I'm looking at the code, it appears that the facility itself could be on the hook for something as simple as not installing panic bars on the doors of the equipment closet holding the service panels.   

Of course, this is 2014 NFPA code and many states/districts haven't adopted the latest revision yet. But it's probably worth a chat with your area electrical inspector to see just how soon this will play out. Panic bars and doors opening outwards seems like a pretty inexpensive fix if it avoids a lawsuit in the future if an accident occurs.
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Tim McCulloch

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Re: Electrical Code Compliance
« Reply #3 on: January 23, 2014, 02:17:57 pm »

I believe that at some point there WILL be an electrician opening up a live box in your facility, and it's exactly THAT electrician who need to have the panic bars on the door in case something goes wrong while he's inside your live panel changing a circuit breaker or whatever. Now that I'm looking at the code, it appears that the facility itself could be on the hook for something as simple as not installing panic bars on the doors of the equipment closet holding the service panels.   

Of course, this is 2014 NFPA code and many states/districts haven't adopted the latest revision yet. But it's probably worth a chat with your area electrical inspector to see just how soon this will play out. Panic bars and doors opening outwards seems like a pretty inexpensive fix if it avoids a lawsuit in the future if an accident occurs.

The way this system was designed, your scenario is unlikely in THIS venue (we can de-energize the entire vault for maintenance without affecting anything else in the facility), but is exactly why the panic bars are a Very Good Thing.  Also seeing how defective client equipment could cause an arc flash when a company switch is energized at the circuit breaker, I can see how this is an issue for the entertainment electrician in addition to the maintenance electricians from the Venue or its contractors.

We'll see about bringing this to venue management.  It's not expensive and requires no architectural changes.

Oh, and those arc flash warning stickers are on all the switch gear, service panels, and transformers, too... :)
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Stephen Swaffer

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Re: Electrical Code Compliance
« Reply #4 on: January 23, 2014, 02:31:49 pm »

Individual electricians need to be aware of egress paths as hey work.  Too often that nice open area becomes a convenient place to stack stuff, and even while we are working we might clutter the area in front of a panel.  Being aware of the requirements for an egress path is a good rule of thumb for a quick glance to make sure you can get away from a panel if you need to-even if it is not in an "electrical equipment room."

A former employer had added an 8000 amp switchgear-but between the electrical contractor and the building contractor and the college educated engineering manager, they couldn't understand that an egress door for the electrical room had to open into the plant and away from the switchgear.  There was no way I was going to get it changed-so my mental note was that if I ever had to work in that room, I would prop the door open giving me an egress path. 

Lawyers may be the ultimate enforcer of safety practices-but there is only one person responsible for my safety when I open a panel.
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Re: Electrical Code Compliance
« Reply #5 on: January 23, 2014, 03:11:17 pm »

Panic bars and doors opening outwards seems like a pretty inexpensive fix if it avoids a lawsuit in the future if an accident occurs.

Forget about the lawsuits, that's the last thing on someone's mind while their clothes are burning. ("I need to call my lawyer. Once I'm off the phone with him, I'll call 911.") It's all about reducing the time to get help when a matter of seconds can be the difference between life and death.

As for cost, it might be a few hundred dollars to retrofit an egress door with panic hardware, but in the grand scheme of a larger project it's a small portion. Many facilities managers might balk at that cost, so they need to be educated WHY it's a good idea, and a place in the safety budget (rather than the fac maint budget) should be found for it.
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Mike Sokol

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Re: Electrical Code Compliance
« Reply #6 on: January 23, 2014, 06:41:40 pm »

Forget about the lawsuits, that's the last thing on someone's mind while their clothes are burning.

You're absolutely correct. I've been first on the scene at a few industrial accidents, and it's amazing how quickly things can turn bad. I don't remember anybody who was injured talking about lawsuits at the time, they were only worried about getting medical attention ASAP. 
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Mike Sokol

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Re: Electrical Code Compliance
« Reply #7 on: January 24, 2014, 10:18:18 am »

From Mike Holt's NEC Q&A Newsletter. Note that the 2014 code includes egress door and panic hardware requirements around service panels which eliminates door knobs that require grasping action to use. They seem to be taking arc-flash very seriously. Also note that the electrical contractor can be held liable if these "non-electrical" egress door code requirements are not met.

I've learned a lot about electrical code compliance from Mike Holt's newsletter and forum. I highly recommend it to anyone involved with electrical power for stage and A-V-L. While his forum won't answer questions from DIY guys who want to avoid paying an electrician, they've responded to all of my questions and comments about audio grounding, bonding, and stage/AVL power. In fact, Mike Holt's son, Michael, has asked me specific questions about NCVT testing for hot-grounds and such.

Here's his newsletter: https://www.mikeholt.com/newsletter-register.php?action=modify

Here's the forum: http://forums.mikeholt.com/

While this thread is not for the code police and I don't pretend to be a code expert, if you do find anything interesting and potentially relevant (such as panic bars on wiring closet doors) please post it here along with the actual code cited.
« Last Edit: January 24, 2014, 10:20:30 am by Mike Sokol »
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Stephen Swaffer

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Re: Electrical Code Compliance
« Reply #8 on: January 26, 2014, 10:32:30 pm »

For me code compliance is about two things-first, a measure of  legal protection for me, secondly to pass inspections-but the reasons for various code requirements are a valuable tool for doing a job safely.  Unfortunately, some code sections are so impossibly vague or all inclusive that they are often overlooked.

Case in point is 250.4.a.1.4.  Bonding of electrically conductive materials and other equipment.  Normally non-current carrying electrically conductive materials that are likely to become energized shall be connected together and to the electrical supply source in a manner that establishes an effective ground fault current path.

What is "likely to be come energized" all about?  How likely?  Our church building has a tin ceiling circ 1910.  Several years ago we discovered that it was energized at 120 VAC.  Apparently,  volunteer had installed some light fixtures and heated up the ceiling.  I have no idea how long it was that way, we discovered it when the connector on a mic cable being lowered through the ceiling touched the tin with a noisy, unwelcome result.

Something to keep in mind when dealing with metal staging/trusses, etc.  Anytime electricity is near these, they are more or less "likely" to become energized.  To be safe, there must be an effective return path to ground.  We got away with the ceiling only because it was quite inaccessible and there wasn't a well grounded surface near it to cause a shock hazard for those who did access it.  But an energized truss or piece of staging near a grounded one could be a very bad situation. 
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Steve Swaffer

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Re: Electrical Code Compliance
« Reply #9 on: January 26, 2014, 10:35:59 pm »

For me code compliance is about two things-first, a measure of  legal protection for me, secondly to pass inspections-but the reasons for various code requirements are a valuable tool for doing a job safely.  Unfortunately, some code sections are so impossibly vague or all inclusive that they are often overlooked.

Case in point is 250.4.a.1.4.  Bonding of electrically conductive materials and other equipment.  Normally non-current carrying electrically conductive materials that are likely to become energized shall be connected together and to the electrical supply source in a manner that establishes an effective ground fault current path.

What is "likely to be come energized" all about?  How likely?  Our church building has a tin ceiling circ 1910.  Several years ago we discovered that it was energized at 120 VAC.  Apparently,  volunteer had installed some light fixtures and heated up the ceiling.  I have no idea how long it was that way, we discovered it when the connector on a mic cable being lowered through the ceiling touched the tin with a noisy, unwelcome result.

Something to keep in mind when dealing with metal staging/trusses, etc.  Anytime electricity is near these, they are more or less "likely" to become energized.  To be safe, there must be an effective return path to ground.  We got away with the ceiling only because it was quite inaccessible and there wasn't a well grounded surface near it to cause a shock hazard for those who did access it.  But an energized truss or piece of staging near a grounded one could be a very bad situation. 
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Samuel Rees

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Re: Electrical Code Compliance
« Reply #10 on: January 27, 2014, 02:55:49 am »

We had a touring theatre show at one of my houses a few ago hang some chandeliers from our light electrics, we discovered later that their cases were hot and our LD got a shock. Essentially our fault, we could have (should have) figured that and not cleared them to be hung.
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Mike Sokol

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Re: Electrical Code Compliance
« Reply #11 on: January 27, 2014, 01:21:16 pm »

We had a touring theatre show at one of my houses a few ago hang some chandeliers from our light electrics, we discovered later that their cases were hot and our LD got a shock. Essentially our fault, we could have (should have) figured that and not cleared them to be hung.

A secondary (and sometimes primary) danger of a lighting fixture or pipe being electrically charged is the "fall factor". I once had a beefy electrician (250 pounds / 18 stones for those in the UK) get shocked and fall from a tall ladder. I was standing directly below him and tried to put my shoulder into stopping his fall. But I was (and still am) a scrappy little guy, and ended up being splatted onto the concrete floor. He thanked me for breaking his fall, but I was really bruised up for a week.

Even a small shock can startle you enough to loose your balance which can become a deadly air ballet if you're up on a ladder or scaffolding when it happens. Testing all pipes and hardware around lighting fixtures for voltage seems like a really good idea. 
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Tim McCulloch

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Re: Electrical Code Compliance
« Reply #12 on: January 27, 2014, 01:38:02 pm »

A secondary (and sometimes primary) danger of a lighting fixture or pipe being electrically charged is the "fall factor". I once had a beefy electrician (250 pounds / 18 stones for those in the UK) get shocked and fall from a tall ladder. I was standing directly below him and tried to put my shoulder into stopping his fall. But I was (and still am) a scrappy little guy, and ended up being splatted onto the concrete floor. He thanked me for breaking his fall, but I was really bruised up for a week.

Even a small shock can startle you enough to loose your balance which can become a deadly air ballet if you're up on a ladder or scaffolding when it happens. Testing all pipes and hardware around lighting fixtures for voltage seems like a really good idea.

Anyone working around power in entertainment should have an NCVT.  Clipped into a shirt pocket, like a chef has a thermometer.  Checking the pipe batten before touching it seems excessive... until you become a member of the 120v Club.
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"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

Mike Sokol

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Re: Electrical Code Compliance
« Reply #13 on: January 27, 2014, 01:46:00 pm »

Anyone working around power in entertainment should have an NCVT.  Clipped into a shirt pocket, like a chef has a thermometer.  Checking the pipe batten before touching it seems excessive... until you become a member of the 120v Club.

One of my electrical buddies who works for the Power Company says he keeps a Fluke NCVT turned on in his shirt pocket when walking though the woods looking for downed (and sometimes energized) power lines after a storm. He says that more than once it's started beeping in his pocket when was several feet away from a hot 11,000 volt line laying on the ground. Touching that would make you a member of the 11KV club, which I don't wanna be...
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Tim McCulloch

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Re: Electrical Code Compliance
« Reply #14 on: January 27, 2014, 02:12:48 pm »

One of my electrical buddies who works for the Power Company says he keeps a Fluke NCVT turned on in his shirt pocket when walking though the woods looking for downed (and sometimes energized) power lines after a storm. He says that more than once it's started beeping in his pocket when was several feet away from a hot 11,000 volt line laying on the ground. Touching that would make you a member of the 11KV club, which I don't wanna be...

I think 11kV membership is awarded posthumously....
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"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

Mike Sokol

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Re: Electrical Code Compliance
« Reply #15 on: January 27, 2014, 02:52:24 pm »

Anyone working around power in entertainment should have an NCVT.  Clipped into a shirt pocket, like a chef has a thermometer.  Checking the pipe batten before touching it seems excessive... until you become a member of the 120v Club.

Fluke makes an LVD1 Non Contact Voltage Tester with a belt clip and an LED light that looks promising for AVL crew. The reason it's only rated up to 300 volts is that the body of the tester is much shorter than Class IV gear rated to 1,000 volts. But I think that's perfectly safe for any US power you might encounter for live sound and lighting. I've already asked Fluke for some review samples, but so far nothing has turned up. I'll contact them again and see what happens.

« Last Edit: January 27, 2014, 03:15:08 pm by Mike Sokol »
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Tom Bourke

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Re: Electrical Code Compliance
« Reply #16 on: January 27, 2014, 03:12:17 pm »

Fluke makes an LVD1 Non Contact Voltage Tester with a belt clip and an LED light that looks promising for AVL crew. The reason it's only rated up to 300 volts is that the body of the tester is much shorter than Class IV gear rated to 1,000 volts. But I think that's perfectly safe for any US power you might encounter for live sound and lighting. I've already asked Fluke for some review samples, but so far nothing has turned up. I'll yank their chain again and see what happens.
That is the unit I keep on my key-ring.  I think it was $25 at Fry's.  It has a soft transition from low to high voltage so you can kind of see how close you are.  You really have to know what your looking for and how it reacts before you trust it.  It also makes a nice little penlight.  Great to have with me at all times.  On a gig I may still use it but I tend to reach for the larger NCVT with the beep and probe end.
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Frank DeWitt

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Re: Electrical Code Compliance
« Reply #17 on: January 29, 2014, 04:16:34 pm »

I picked up this surface mounted outlet on Ebay (I collect old electrical gear)

The cord you see is solid conductor 23 gauge copper.

Worlds smallest distro?
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