Power Surges & Intelligent Fixtures

DeenT

Active Member
I'm hoping someone can give me a little insight into some issues we've been having at our theatre recently. Over the last few weeks, we've been having power blips in the building.

After one, where the power flickered 3 times in a row, the next day one of our moving head lights (Mac 2000 Profile) stopped working. Upon inspection, a fuse on the PCB had blown.

Fast forward a few days, we get told by maintenance that another brief power outage had happened overnight. We immediately checked all of our equipment. I powered up my other moving lights (Techni-Lux Tracker 575) and 2 of them started vigorously shaking in place. These two fixture's power are paired together. We went to the catwalk where the power connects to the stage-pin connection for the dimming system, and the connection was completely melted.

Some info on our dimming system: We have a strand dimming system and the power for all of our intelligent lights are on non-dim/relay packs. We keep all of these circuits off unless we are using the lights. They are also programmed to turn off in the early AM in the off-chance that we forget to turn them off.

In the first instance, the fixtures were powered on during the power outages. However, the second instance, the power was already shut off to the fixtures.

I know you can't put these fixtures into surge protectors, but is there something we can do to help prevent these issues? I saw an old post on here but I know things have changed over the years.
 
The Mac 2000 fuse could have been a power surge, but I believe the melted connector is a red herring. These types of power surges last a fraction of a second and the kind of heat damage you describe happens over time. I don't know what kinds of connectors your facility uses, but you probably had a loose screw terminal or a loose stage pin connector at that location. It's a good thing you noticed, because it could have caused a fire.

Were the Mac 2000s (or their relays) powered up at the time? If not, I doubt an open relay/ND circuit was passing a power surge. If the relay was closed/on, the fuse could theoretically have blown due to a surge or the fixture's continuous attempt at a hot re-strike; but that's just an educated guess.
 
Were the Mac 2000s (or their relays) powered up at the time? If not, I doubt an open relay/ND circuit was passing a power surge. If the relay was closed/on, the fuse could theoretically have blown due to a surge or the fixture's continuous attempt at a hot re-strike; but that's just an educated guess.

Yes, they were powered up at the time.
 
Color me "skeptical" because in 20 years of working with movers I've not seen damage that I can attribute to "surges" other than from a lightning strike to PoCo lines.
 
On an related note, when the power has problems and the new construction across the street, which of course is on the same feed as your building causes power failures and the oh so fun power back on surge, it can cause problems. Like to my orchestra pit control system, fire curtain system controller, a really large shop to stage fire door, wipe out the memory on a acoustical banner controller and more then likely some AV equipment. Luckily all my movers and LEDs are on relays and have been off when these hits have happened. Yep, bad power is no fun. I've been fixing things and having surge protectors put in for the last six weeks.
 
On an related note, when the power has problems and the new construction across the street, which of course is on the same feed as your building causes power failures and the oh so fun power back on surge, it can cause problems.

Funny you mention this. We have an old hotel across the street that is being renovated and I believe the city said they were going to be doing something power related as we share the same feed. Never even put the two together as to why our power could be failing.
 

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