I was working on a commercial at a farm last week. This is the electric in one of the barns.
Sketchy at best; no cover, sloppy wiring, and probably never inspected. I see a lot of this kind of thing on location. It always makes me cautious.
We often are shooting in old locations for looks like vacant factories, abandoned buildings, etc. The electric in these locations is often in poor condition.
If you see bare wires, assume they are energized. They often are.
I don't really have any great words of wisdom about this other than to assume the electric is possibly not usable for anything other than the minimal service. Even then, it is worth checking for problems like reversed neutral/hot, no ground, and even voltage present on the ground.
I've got many war stories. Here are a few I remember:- I was gaffing a commercial at a factory. We kept immediately blowing the lamps in tungsten fixtures. A house "electrician" explained that some of the circuits were 208 volts for their use even though the receptacles were NEMA 5-20R. It was easier for them to put standard 5-20P plugs on the equipment than use the correct connectors. The receptacles were not even marked. Crazy.
- The worst electric I have ever seen was at an old distillery in Kentucky years ago. The service could not handle our 1200 watt pars. (Yes, it was a long time ago.) I went to look at the service and couldn't believe it. The box was outdoors, with no cover, and with wires hanging out of it. That distillery burned-down a few years later. I'm guessing from an electrical fire.
- I did a tie-in at an old unused school building that could have ended badly. It was the only time I ran into a "high-leg delta" service but that was not the problem. (Yes, I did know what it was. It's a uncommon service that provides 3-phase power and single-phase power. The 3 hot legs provided 3-phase service but one leg--the high leg--provides 208 volts to neutral! The high leg should have orange tape. You don't want to run that to a lunchbox!) I went to check the tie-in during the day. I noticed that one clamp had slipped off the bus bar slighting when it was tightened. It was touching the insulation on the back of the box. There was a danger of a catastrophic short if the clamp came into contact with the metal back of the box. The insulation was merely some heavy paper materiel. I shutdown the power and reattached the clamp; this time with some rubber matting behind the bus bar just in case. There were no issues with it for the rest of the shoot but it made me realize the real dangers of tie-ins. I haven't done a tie-in in years. I always recommend getting a genny anymore.
- I was at a store where our lights kept flickering or not working at all. I check the voltage. The entire store was running on 105 volts. Surprisingly, it was a new building. I'm guessing the electricians that put in the transformer, never check the output voltage of the transformer. Yes, that is something that sometimes needs to be adjusted.
- I did a tie-in once at an old stock-yard building. I metered the box before hand. One leg, even though it showed voltage, was dead. There was no power on it. I have no explanation.
- I did a tie-in once at a factory. (It was a safe tie-in to de-energized lugs.) The cover of the box had a huge burn/welded metal spot on the door. I asked the house electrician about it. He said an electrician at the factory was tightening a lug that was energized. I have no idea why that would happen other than carelessness. The box had a disconnect. He said when the hex wrench came in contact with the door, it was a dead short. That had to have been terrifying!
- Another tie-in story; I was best boy electric on a movie at an old school. I tied-in to a 3-phase 400 amp box. Like I always like to do, I checked on the tie-in during the shoot. The tie-in was fine, but I was curious about the box. You could see at one time this box was full of breakers, but now it only had a handful. Then I noticed the main cartridge fuses for the box. They were not 400 amp fuses. They were 100 amp! I did not have spare fuses either. In a panic, I checked the load on each leg. One was 90 something. The others were in the 80s. I quickly went to the gaffer and told him the problem. We were cautious about plugging in lights rest of the night. We made it without blowing a fuse.
My final words of wisdom (I hope it's wise) is to always have respect for electric. It's not complicated but mistakes can injury or kill. Nothing we do is worth anyone getting hurt.
PPS: The oldest electric service I have ever seen and it was still in use:
https://electricgrip.blogspot.com/2015/10/oldest-electric-service-i-have-ever-seen.html