One of the most important skills for all set electricians is to follow best practices with electricity by doing proper wiring. It's important because we need our equipment working properly and reliably. It is critically important for safety.
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| Not best practices! |
This is a 60 amp bates plug on an Arri 4K ballast. This is a terrible wiring job. The cable has been trimmed back too far with no strain relief. Strain relief is essential for maintaining reliable connections.
(If you have not seen these color codes before, these are Euro color codes. It is because this is an Arri ballast from Germany. In Europe, brown is hot, blue is neutral, and yellow-green is ground. Note in the USA brown is 277/480 volts with gray as the neutral.)
This is a poor job of crimping terminals. It looks like the crimps were made by smashing the terminals with a chisel. I would expect under a high load, these connections will over-heat (because of poor contact) and will eventually fail. The wires were poorly stripped, too. Some of the individual strands were cut-off.
This plug was in good condition however so I rewired it.
Here is the finished re-wired plug:
There is now excellent strain relief with the jacket of the cable fully extending into the plug housing. I've put on new terminals. These are steel high-temperature terminals which will handle the high amperage and heat.
Always use a good crimping tool. This is the one I have:
A crimping tool is a precise piece of equipment for crimping to the proper dimension.
A small mistake I sometimes see is the crimp on the wrong side of the terminal. The crimp, the indentation, goes opposite of the split side of the terminal.
I used a little anti-oxidant (for copper) on the terminals. This is not required but will keep these terminals operating cooler and prevent corrosion. (More about this in the PS.)
As a final step, I spray just a little silicone spray in the plug. This will help keep moisture and corrosion out of the plug. Bates plugs are definitely not weather resistant though we use them outdoors all-the-time.
I also was making some 60 amp cables. I like this style of plug better especially because these can be serviced easier in the field if needed. Note with this style of terminal, it is important to always use a ferrule on the ends of the stranded wire for proper connections.
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| I used some anti-oxidant, but the pink stuff was already on the plug. This Marinco plug came new out of the bag with it on there and the set screws installed. I'm thinking the plug had been used or was subjected to some kind of quality control testing. The pink is probably some kind of thread-lock. |
PS: I learned using anti-oxidant on high-amperage connections from an industrial electrician at a factory many years ago. I was a set electrician required to do several tie-ins over a couple days. Like most industrial locations, their house electrician supervised my work. We had time to talk shop. I learned much from him in a couple days about best practices.
One of the things we talked about, was high amperage connections over-heating particularly bates plugs. He suggested using anti-oxidant on the connections. He used it routinely on his work at the factory.
I started using it on 100 amp bates connections with great results. Plugs with anti-oxidant were relatively cool to touch while plugs without were hot.
I've been using it on high-amperage connections ever since. Note the anti-oxidant you want to use is for copper or copper/aluminum.
Back in the day, one of the rental houses I used to work with had 12-light maxi-brutes powered with an 100 amp bates cable. I used to love these lights. It was a brand I haven't seen since; very light-weight, and easy to work with.
Doing the math, 12-1000 watt pars at 8.33 amps is 99.96 amps under ideal conditions. These lights routinely burn-up bates plugs which is not surprising. We were overloading these plugs (which is not best practices!).
I started servicing 100 amp bates cables specifically for these 12-light maxis. I would check each plug; straighten the pins, add anti-oxidant to the terminals and tighten them. After servicing, I never had trouble with any plugs. The plugs would run warm but never over-heat.