So our lighting designer made us these custom "boxes" for our grid. They are basically a multi cable running into a metal box with c-clamps and for plugs. We place them on electrics. So yesterday during a crewe call, one of the plugs was not working. So we used a gam check and it said there was a hot ground reverse. We turned everything off and opened the plug and reversed the hot and ground, but that didn't work. After rewiring it back to the way it was it still did not work. We went on a dinner break and once we came back it worked again. Any reason why this would happen?
Box not working then working again.
- Thread starterPDSaccman
- Start date
They must be possessed. One time we had a 360Q that wouldn't work, we checked the circuit and had power, we replaced the cap with a known working one and it still didn't work. i think we spent half an hour screwing with this thing to no result. We ended up replacing the entire fixture and them putting big red x's on that fixture and locking it in an office under the assumption it must be possessed. I've also had flourescent fixtures that didn't work before lunch, we left them on when we went to lunch and when we cme back it was on. I turned it off and then it wouldn't come back on. I replaced the ballast and it still wouldn't come on. An hour later it randomly started working and has worked fine ever since as far as I know.
I guess my answer is that sometimes electric things have a mind of their own. There is probably some minor problem somewhere but to try to track it down is nearly impossible.
I guess my answer is that sometimes electric things have a mind of their own. There is probably some minor problem somewhere but to try to track it down is nearly impossible.
Home brew equipment always make me uneasy. We on CB try to be treat giving electrical advice over the internet with the utmost care. We really have no way of knowing how competent your LD is at electrical work. Without this box physically in front of me, I don't feel comfortable offering troubleshooting advice. Even if it WAS in front of me, I might still not want to touch it. An off the shelf product is a know entity, but something whipped up in your own shop is a one off that could be anything from 100% standard and normal to a "what in the heck...." kind of thing. They sound like normal break out boxes, but there's no way to tell over the Internet.
But pictures help.
But pictures help.
A couple of things:
What you have is probably best termed a drop box.
A hot-neutral reverse would not prevent a fixture from illuminating.
Like the (Edison) outlet tester, in certain cases, the GamChek will give erroneous results. There's a link in the wiki.
I'd want to know what was happening at the other end before I went swapping wires. I'd also check the multi-cable's insulation along its entire length for visible signs of failure. Then I'd run a continuity check on every conductor.
"Turning everything off" is (maybe) NOT ENOUGH. When opening any female, LOTO procedures must be followed. I've been shocked by a receptacle when the console was at zero, but there was still leakage voltage present from the dimmer.
.
Gam checks and similar devices are a nice tool to have in the tool box but I rather use a true rms voltage meter to verify electrical gremlins. Meter between hot and neutral, hot and ground, neutral and ground and see if you can tell what is truly going on. I have had quick testers throw me off in troubleshooting. Also meter again with a load attached to look for any change. I use a twofer and meter the second tail while the fixture is connected to the first one. Also remember with dimmers you will see some voltage even when at zero. What you are primarily looking for is are the conductors actually reversed and what is your voltage between neutral and ground. When you have a high neutral to ground voltage there is something going on with your distribution equipment that needs to be addressed. Once at a fabrication facility we kept on having problems with the plc's randomly outputting weird data when metering the incoming power we found that there were 70 volts between neutral and ground. Turns out there was a problem on the electrical providers side but after they got it straightened out everything started acting normally.
doctrjohn
Active Member
I often use this method myself, but I would suggest first making sure the twofer is properly wired before using it for testing/troubleshooting; particularly if it looks like it was homemade or repaired at some point. You might just save yourself a lot of head scratching and additional frustration... DAMHIKIJK
Best,
John
