Situation: Many light poles in campus walkways. 3 circuits (277V) feeding them. At times ballast go bad and circuit trips or bad connection in cristie(sp) box. Spend many hours tracing to exact pole(s)
Problem: How to save time in finding correct pole which is bad. When the circuit trips it trips the hole bank of lights (20) lights or so per leg (HPS 100W). I was thinking of putting some sort of in-line fuse w/ a popout indicator on each pole. What do you guys think any suggestions? It's a real hassle trying to peel of switch legs here and there. There's about 20 Christie boxes.... Any suggestions?
I would mark the poles that represent 1/4, 1/2, and 3/4 points on the circuit. Everytime you have a problem on that circuit, go to the pole that represents the halfway point on the circuit, and break the joints. Go turn the breaker on. If the circuit breaker trips, you know the problem is on the first half of the circuit. If it doesn't, you know that the problem is on the second half. Remake the joints at the halfway point, and go to either the 1/4, or 3/4 point, and start the process over again. This is know as "half splitting". Good Luck. Regards, Doc
The Watt Doctor Altura Cogen Channelview, TX
Re: walkway light poles on campus#8238 03/14/0209:25 PM03/14/0209:25 PM
Thanks Doc, good advice. Unfortunately at the University, before I got there there have been many runs which have been re-pulled, conduit abandoned and backfed... it's a real mess. The best I/We could do is disconnect at a halfway point which you mentioned and at this point 20 or lights are out and it's like trying to find a needle in a haystack. We certain sectors in the campus which are broken up exactly the way you have mentioned. Troubleshooting not too bad on that one. I was just wondering if there was a way to install some sort of pop-up indicator on tha actual pole or via an inline splice or something. I know I could physicaly install it but does this sound kind of McGyver-ish?
Re: walkway light poles on campus#8239 03/14/0210:15 PM03/14/0210:15 PM
I like your fuse idea. That would help identify one or more overloading fixtures.
I have a feeling that these Ballasts do not have a Power Factor Correcting Capacitor installed. Have recently installed some new Hubbell HPS fixtures [100 watt HPS - ANSI S54 lamp] and there was no Capacitor included. That makes the PF only 50%, so there's close to 2 times more current drawn.
I included this to give a possible fix - try installing Capacitors to lower the Line Amperes / KVA.
Scott " 35 " Thompson Just Say NO To Green Eggs And Ham!
Re: walkway light poles on campus#8244 03/15/0211:08 PM03/15/0211:08 PM