House Light Issue

midgetgreen11

Active Member
Yesterday, I was running a normal dress rehearsal that i was stage managing. The rack was about ten feet behind me, and i heard a bang come from it, and all the house lights kicked on. There are lights that have been dead since I've attended the high school, or just not patched in, that came on.


Any ideas as to what this could've been?
 
Yesterday, I was running a normal dress rehearsal that i was stage managing. The rack was about ten feet behind me, and i heard a bang come from it, and all the house lights kicked on. There are lights that have been dead since I've attended the high school, or just not patched in, that came on.


Any ideas as to what this could've been?

Sounds like so sort of emergency lighting system kicked on. Did you lose the stage lights? Does the rest of the system function normally?

Often they (ELTS - "Emergency Lighting Transfer Switch") are set up to power house lights that run through normal dimmers. If the power goes out, or if someone hits a panic button, or if the fire alarm is tripped, the branch circuits that feed certain house and work lights will switch to an alternate power source.

Now, since you said these are lights you've never seen on before, it sounds like a slightly more simple situation. There's some switch (I mean big switch, not a wall light switch).....that "banged on" and turned on those lights. It may be that someone hit a panic button somewhere. Or they were working on the fire alarm panel. Either way, you probably want to let your building folks know.

If you can take some pictures of what you think was the source of the bang, we might be able to offer more help.

--Sean
 
Did it really sound like a "bang" or was it more of a "ka-chunk"? Either way, it was probably a contactor energizing, for the reason(s) Sean listed above. Is there a rack or panel that doesn't have dimmers in it next to the dimmer rack? Did the lights that turned on ever turn off? And if they did, did you hear a reverse "ka-chunk"?
 
sounds like our house lights. In our house we also have 47 color blasters (Led lights for some sound pannals just above our arch) every time we turn our light board one led and one house light will turn themselfs on then turn off after ten minutes. But there is no sound when it happens.

though we do have custodians who have to check our E. Power once a month. Last time they check it one of our followspots were on and it burnt out the lamp.
 
It's possible that the light you saw come on;

"....lights that have been dead since I've attended the high school, or just not patched in, that came on."

Were secondary emergency lights. A lot of systems have two set of lamps in x number of fixtures that only activate when the emergency lighting is activated. Thus the "normal" lamps may very well be burnt out but the secondaries, only used in emergencies, are just fine. This is just a way of reinforcing what everyone else has said which is that your emergency lighting system has tripped.


 
once again, i'm betting it was the emergency system. Commonly schools tech people will test the system to make sure the generators and switch gear are working properly. I know my school did this, especially with their district office where all of their servers were. Its good to get exercise the emergency system every now and then.
 
I would also guess that this is part of emergency lighting system. This is the time of year that people start to either test systems or accidentally trip them. Why? Because as we move towards summer the energy draw of large building increases as people start firing up the AC. Many cities test the power grid to ensure that all the public buildings can run their AC and whatnot around this time of year too, and a situation like what you describe could prove that they need more power!

Of course there are lots of other reasons that the emergency system could have kicked on. We had ours kick on during a show last year because some device in the building shorted and caused the transfer switch to think that there was a power loss so the generator and emergency light kicked on. It happens.
 
As said above, sounds an awful lot like a contactor. I remember I room I worked a show in a long time ago where the house lights were on the dimmer system, but you could still bring them on by hitting one of several "panic" buttons. These buttons would transfer the lights off of the dimmer and directly connect them to AC power, but were not part of the "emergency backup lighting." (Nice big relay clunk) I guess the idea was that security (or maintenance) could kick on the house lights without needing access to the dimmer system.
 
I have been in venues where the entire dimmer system, actually all of the "show disconnects" were on generator power, so if the power went out, the show could still go on. Building was powered by 3 or 4 BIG cat gennies. When i say big i mean one story house big.
 
For the Pay-Per-View and televised events I do, standard practice is to run the show off generators, with House Power as back-up.

However, the TWELVE emergency power Caterpillar generators didn't keep the Bellagio Hotel & Casino from being shut down for three days in 2004. Never did hear the "official" reason why that happened. (I think it may have been JD! :)) Oddly enough, the Spa Tower expansion was being built at the time, and all the temporary construction lighting stayed on, while the rest of the property went dark. Tens of millions in lost revenue, but that's the reason for insurance.
 
Can I ask how? Or is that a secret (or already on here???)
You may ask how. "Can" connotes ability; "may" implies permission.

And it's in JD's signature, but I don't know that he's ever told us the story.
 
Where exactly would one find a panic button? I've never seen one in either the theater in my high school or the TV studio in there.
 
Where exactly would one find a panic button? I've never seen one in either the theater in my high school or the TV studio in there.

CD80 dimmer racks have them, but concerning ELTS systems one would be wherever the ELTS system is controlled from. I wouldn't be surprised to see that located near the controls for a fire alarm system either.
 
We had a Leviton System, I'm pretty sure the i96 rack had something for it but that was all the way back behind stage in a electrical closet. I know when the fire alarm system kicked it it worked as it should but is there never a reason for a person to hit a panic button?
 
We had a Leviton System, I'm pretty sure the i96 rack had something for it but that was all the way back behind stage in a electrical closet. I know when the fire alarm system kicked it it worked as it should but is there never a reason for a person to hit a panic button?

Testing that the loads connect to the system. Take for example two weeks ago when we were caught troubleshooting our CD80 racks. The lights in our shell ceiling panels were not turning on, and we were able to eliminate the possibility of a dimmer or control problem by hitting the panic button, turning everything and its brother on. A quick pull of a meter, and about 10 minutes of flipping through original schematics of the shell system revealed freakin' mercury tip-switches. The panic button easily eliminated the possibility that our premier system was on the fritz again though.

In ELTS egress systems be it an emergency and the sensors don't trip, or simply testing what would happen in the event the sensors don't trip, panic buttons do have a use, though used rarely.
 
Can I ask how? or is that a secret (or already on here???)

I though I might have already told this tale in brief somewhere, but here goes:

(1980) In Wildwood NJ, there was a large club that was a converted theater-in-the-round called The Playpen. (About 3,500 capacity) It was part of an area known as Diamond Beach, which included an amusement pier/water park, a hotel, a restaurant, and the club. Due to a trucking problem (drunk truck driver) we arrived 4 hours before showtime with a 120k show to set up. The club was in the middle of a large vacant sand lot. The building was open but there was no one there except us. We had been told there was plenty of power. I did a quick recon. There was a transformer pad outside the building that fed a 1930s vintage fuse based distribution panel that was in a locked cage. The so-called tie in point was a 200x3 panel with no cover that also provided branch circuits to the stage area. All three main lugs were stripped out. Next to it was a box that fed a 60hp electric motor that drove what looked like a v8 engine that was actually the compressor for the AC. The third option was a very large pull box. I removed the lid and found (STEVETERRY will cringe) a large Bakelite block with four large copper terminals. On the input were lugs fed with doubled up 4/0 copper. This fed (un-fused) a pile of 2 gauge wires that went out through conduit to feed other panels in the building. OK, this was a code nightmare, but would work as a tie-in point. I installed a 200 amp disconnect with cam tails for our equipment, but made a firm decision not to tie into this pile live. As the cage was locked and the pole switch feeding the transformers was not, I threw the pole switch and then went about finishing the job. That went well, but just as I was putting the last screw back in the pull box cover, I heard screaming that went something like this:

"Who (forty expletives) turned off the (more expletives) power to my (more expletives) hotel??"

I saw a man storming his way toward my area. His face was not only the color of a strawberry, it had the matching texture! I quickly darted out the back door and threw the pole switch back on, then reentered to face my execution. There was no real attempt at debate, I just kind of let it pour on me, interrupting only to say "yes sir" at each pause.
What I had missed on my overview were several large pipes in the middle of the transformer pad that served as underground conduits to feed the hotel, the restaurant, and yes, even the amusement pier. Me bad!

The show was there for the full summer. About two days later, the owner (a retired PA senator) invited me to dine with him. (I was half expecting him to feed me then take me out back and shoot me.) He actually apologized and treated me to a great surf & turf meal! (Amazing what a few sold out shows will do to a man's disposition.)

The hardest part was listening to the crew recount the story hundreds of times over the course of the next few years! Interestingly, when we returned the next summer, there was a nice company switch waiting for me. ( picture of show taken 2 nights later http://witness.velmadinkley.com/pics2/pp001.jpg )
 

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