Just finished today, got all the lights working, put a new gas valve in the unit heater and probably scored my boss a garage door fix job. I will answer all...
Fixture;
HPS
TH 400M 277 HC5 HSG
PRI volts 277
PRI amps 1.75
(Just like this first schematic
https://www.electrical-contractor.net/ubb/Forum15/HTML/000019.html )
Bulbs; M400/C/U
(I installed core and ballast kit 71a6071-001D multi tap CWA)
Breaker; (They are switched at breaker but run 24/7 I think)
Interrupt rate max RMS symmetrical amps type BDQ
14000 A 277 HACR
14000 A 125 HID
The run is #10 and aprox 2-300 feet MTW
Panel; 480Y/277 3Phase 250amp
I could draw the cable diagram and it would be clearer, but I haven’t posted pix here yet and I got to learn the setup. What I found was another loose wire nut in the end of the furthest string and the two fixtures one upstream one downstream primary windings on transformer smoked. I also found the neutral going back to the panel pulled out of the wire nut in a 600 box and lost in the conduit, so I do not know how these lights were working without the neutral leg. I suppose the wires could have been grounding out on the conduit enough to complete the circuit. So I'm sure all this poor installation was the cause of all this. I'm sure it was poor installation because all the loose connections were in the 600 boxes and the fixtures are connected by a cord with box connectors (isolated from vibration). I had a new guy trainee/helper that’s like one of those guys that yeses you to death, "OK go do that while I do this,...you know how to do that?...OH..Ya ya ya right right right". I fused everything because I don’t want to have to try to find smoked ballast with a lift again, now if one smokes it will only be that one and it will not take half the warehouse out with it. I used inline type fuse holders and I put them in the boxes because they were the only ones I could get at the time, and as it turns out it was a good thing because the guy I was with who I showed how to wire the things more than once wired a short in the last fixture we did and sure enough I had to go back up and get it and show him.
Now why is a HVAC tech doing electrical, because I'm working for a commercial maintenance contractor? Maintenance can mean a lot of things. I prefer to stick to HVAC because that is where I have all my technical training but I got to do what I got to do for the family. The HVAC biz here is very competitive and I'm trying to start up a HVAC biz for my boss now, but in the mean time I do whatever for $$$, like a prostitute.
One thing I'd like to know is can I have cut my trouble shooting time down significantly with a megger?
