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Author Topic: locking out outlets  (Read 1536 times)

Taylor Hall

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locking out outlets
« on: June 04, 2019, 07:11:50 am »

We had a near miss this past weekend where someone (not us) backstage tried to pull the plug on a piece of equipment so something else could be plugged in. Luckily one of our techs was nearby and stopped them.

Is there any electrical/fire code that forbids enclosing or otherwise locking out any flavor of power distro (stringer box, pagoda, power strip, etc.) so that nothing else can be plugged in or unplugged unless by proper personnel? If nothing else we want to safeguard against something like this from happening to mission-critical devices, or devices which require a cooldown period (discharge fixtures, projectors, etc), so it's not like we'd be locking up every edison we have.
Obviously better security would solve this, but we don't always have that luxury at some events. Thoughts?
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Mike Sokol

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Re: locking out outlets
« Reply #1 on: June 04, 2019, 07:18:05 am »

We had a near miss this past weekend where someone (not us) backstage tried to pull the plug on a piece of equipment so something else could be plugged in. Luckily one of our techs was nearby and stopped them.

That's a great question. I once had a food service worker unplug my video projector hot right in the middle of my seminar because they wanted to plug in their big coffee urn. Yup, popped the projector bulb to the tune of $500 or so.

What about a yellow flag with Velcro that said "DO NOT UNPLUG". 
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Taylor Hall

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Re: locking out outlets
« Reply #2 on: June 04, 2019, 07:25:33 am »

What about a yellow flag with Velcro that said "DO NOT UNPLUG".
If people bothered to comply with signs (let alone read them) OSHA would be bankrupt :P

In all seriousness, we do try to tuck everything away as best we can to be out of easy reach, and we've only ever had this kind of issue with stringer boxes and power strips as they are more "familiar" to the layman than a multi-phase distro box or anything rack-mounted. I know that you can buy covers for power strips for residential use to baby-proof things or declutter, but I'm not sure how a device like that would fly in a production setting.
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John Roberts {JR}

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Re: locking out outlets
« Reply #3 on: June 04, 2019, 09:43:02 am »

I guess you could always leave one free outlet, but that might still not be enough for some.

JR
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Stephen Swaffer

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Re: locking out outlets
« Reply #4 on: June 04, 2019, 12:42:20 pm »

The biggest issue I would see is that code/safety is concerned primarily with being able to disconnect equipment in the event of something bad happening.  You might run into an inspector that takes issue-though there are provisions for restricting access to authorized personnel.

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Steve Swaffer

Taylor Hall

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Re: locking out outlets
« Reply #5 on: June 04, 2019, 01:28:00 pm »

The biggest issue I would see is that code/safety is concerned primarily with being able to disconnect equipment in the event of something bad happening.  You might run into an inspector that takes issue-though there are provisions for restricting access to authorized personnel.
That was my main concern as well. The only thing I can find through my searches so far is that electrical/fire codes require some kind of cover plate on the outlet box itself, but nothing about restricting access to said outlets.

The one thing that could possibly be used as precedence in this are in-floor electrical drops which are usually locked or taped shut once any runs have been made. While slightly different from a mobile stringer box or similar, the concept of sealing it off is mostly the same in the end.
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Jonathan Johnson

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Re: locking out outlets
« Reply #6 on: June 04, 2019, 01:59:56 pm »

The biggest issue I would see is that code/safety is concerned primarily with being able to disconnect equipment in the event of something bad happening.  You might run into an inspector that takes issue-though there are provisions for restricting access to authorized personnel.

The thing is, though, plug-and-receptacle connectors SHOULD NOT be considered "disconnecting means" if they are not listed for breaking capacity. If they aren't disconnecting means, then securing them from unauthorized disconnection should not be an issue. For a typical 15A plug and receptacle (NEMA 5-15), how do you know if it is rated for 15A breaking capacity?

(Now, I do not know what the Code says about this. Does the Code consider all plug-and-receptacle connections to be disconnecting means? Are all NEMA plugs and receptacles supposed to have breaking capacity at their rated amperage? Judging by the number of burned receptacles and plugs I've seen, I'm guessing "probably not." This is probably why British receptacles have switches.)

Note, however, that Neutrik powerCON TRUE1 connectors ARE designed for breaking capacity, so an astute inspector might not like seeing THEM secured! On the positive side, I haven't seen any coffee urns or vacuum cleaners with a TRUE1 plug.
« Last Edit: June 04, 2019, 02:20:02 pm by Jonathan Johnson »
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John Roberts {JR}

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Re: locking out outlets
« Reply #7 on: June 04, 2019, 02:02:41 pm »

Perhaps a length of colored gaffer tape over those plugs would give people the hint to not unplug them during a show. Maybe no tape over plugs that don't matter.

If there was an actual emergency they could still easily be unplugged.

JR
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Jamin Lynch

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Re: locking out outlets
« Reply #8 on: June 04, 2019, 02:21:05 pm »

Maybe?
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Frank DeWitt

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Re: locking out outlets
« Reply #9 on: June 04, 2019, 05:08:30 pm »

We had some things at church that people would keep unplugging.  We switched the plug and outlet to non standard.  It has solved the problem.
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Rob Spence

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Re: locking out outlets
« Reply #10 on: June 04, 2019, 05:48:26 pm »

What about the covers for outdoor recepticals?
I know some of them have provisions for a small padlock.
I see them all the time in public parks.
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Paul G. OBrien

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Re: locking out outlets
« Reply #11 on: June 04, 2019, 09:16:42 pm »

We had a near miss this past weekend where someone (not us) backstage tried to pull the plug on a piece of equipment so something else could be plugged in.

To plug in a phone charger maybe? I've seen that twice now, most recent was an unknown person that unplugged a set of powered side fill monitors to charge their i-thingy and the previous was a musician that unplugged his own floor monitor during a break to charge a phone and then of course complained that his monitor didn't work once the next set had begun.
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Erik Jerde

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Re: locking out outlets
« Reply #12 on: June 04, 2019, 09:19:25 pm »

We had some things at church that people would keep unplugging.  We switched the plug and outlet to non standard.  It has solved the problem.

The problem is they don't realize it won't work for them till they unplug it.  Unless you've cut everything over to 100A stage pin..... :)
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Stephen Swaffer

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Re: locking out outlets
« Reply #13 on: June 04, 2019, 10:30:21 pm »

The thing is, though, plug-and-receptacle connectors SHOULD NOT be considered "disconnecting means" if they are not listed for breaking capacity. If they aren't disconnecting means, then securing them from unauthorized disconnection should not be an issue. For a typical 15A plug and receptacle (NEMA 5-15), how do you know if it is rated for 15A breaking capacity?

(Now, I do not know what the Code says about this. Does the Code consider all plug-and-receptacle connections to be disconnecting means? Are all NEMA plugs and receptacles supposed to have breaking capacity at their rated amperage? Judging by the number of burned receptacles and plugs I've seen, I'm guessing "probably not." This is probably why British receptacles have switches.)

Note, however, that Neutrik powerCON TRUE1 connectors ARE designed for breaking capacity, so an astute inspector might not like seeing THEM secured! On the positive side, I haven't seen any coffee urns or vacuum cleaners with a TRUE1 plug.

Code does not require disconnecting means to have breaking capacity.  For several appliances, cord and plug is a valid disconnecting means as long as there is also a way to turn the appliance off.  A disconnect under load may damage things-but I assume that is considered less annoying than burning the building down because something could not be disconnected?  The wisdom can be debated all day long, but code requires disconnecting means for most everything and "cord&plud" is one of the more common means.

I think the outdoor cover is a good idea. Another thing that might work if it is a venue you can get things changed (even the cover requires that) would be a single twistlock receptacle,.  The single would look unusual enough I think most people would leave it be (hopefully when they feel it is stuck they wouldn't just yank on it?)
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Steve Swaffer

Mike Sokol

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Re: locking out outlets
« Reply #14 on: June 05, 2019, 10:25:46 am »

We had some things at church that people would keep unplugging.  We switched the plug and outlet to non standard.  It has solved the problem.

There's a plethora of choices, not all of which are 120-volt.  :o
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Frank DeWitt

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Re: locking out outlets
« Reply #15 on: June 06, 2019, 09:56:49 pm »

we used a L5-15r twistlock duplex I red.  The red twist lock that shows serves as a warning that removing the plug wont give them what they want.
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Craig Hauber

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Re: locking out outlets
« Reply #16 on: June 14, 2019, 10:16:50 am »

There's a plethora of choices, not all of which are 120-volt.  :o
The issue here is unplugging
the average dumdum will still yank those out only to find out after it is out that it isn't usable -but the damage has supposedly been done at that point.

If this is such an issue:

1) police your used outlets better, leave obvious high-traffic ones wide open and run cord to more out-of-the-way hidden ones -such as behind furniture (or bury entire area with your empty cases or set up control round it)

2) distro with large mains connection and all proprietary connections for your systems (Powercon, T-L, stage pin etc..)

3) UPS (yes they come big enough for a giant projector, they may be heavy and not last long, but if you're popping $500 lamps every time I would figure it would pay for itself fast) 

4) Invest in gear that tolerates power failure during use.  -Because grid outages outside of the venue happen too and I wouldn't want gear harmed by sudden power loss of any kind
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Jonathan Johnson

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Re: locking out outlets
« Reply #17 on: June 14, 2019, 12:57:45 pm »

The issue here is unplugging
the average dumdum will still yank those out only to find out after it is out that it isn't usable -but the damage has supposedly been done at that point.


You could always put up a sign
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Re: locking out outlets
« Reply #17 on: June 14, 2019, 12:57:45 pm »


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