I'm having a problem with some 400W MH commercial lights. When they are switched on in the morning they trip the breaker. If I reset the breaker sometimes they'll start fine, other times it'll trip again. I'd describe these as lighting units 20 through 30 of the same brand and configuration. Any suggestions?
there are few suggestion with the trouble shooting Dave55,,
one is check the starting current and running current if 400 watts MH CWA ballast the starting current useally lower than running current btw ,,
second thing you can do is check the breaker to see how much inrush current during start up if not very high maybe the breaker is weak from all the abuse of inrush current there and there is a breaker that can dealt with high inrush current assocated with HID or transformers in the circuits
the other thing you can do is put the indivual fuseing for each lumiaire but that will drive up the cost for time and materals
hope this can help you with some question you are asking this one dave
Merci , Marc
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)
Re: MH High-Bay Lights#49609 03/11/0501:14 AM03/11/0501:14 AM
Dave: Suggestions & comments: MH start current is higher than 'run' Is the CB a HID rated/labeled breaker? How many fixtures on the circuit? What is the voltage? Does the breaker 'trip' instantly? or do the lights 'start-up' partially? IF they do, then the ones that 'started' may require a 'cool-down' before re-striking; lowering the start-up current!
I would replace the breaker with a known 'good' (or new) breaker and clamp the circuit to get more info. You may have a bad breaker; or you may have a ballast that is going bad.
Another reason I try to spec fuses at each hi-bay, and at each pole or head. Better to have one light out then the whole circuit!
These are interior 400W MH multi-tap lights approx. 18' off the floor. I have them in the 208 volt leg, and the voltage is high, approx. 218 volts. There are six of these units on a 20-amp cicuit protected with a std. Square D QO SP breaker. It just occurred to me that this breaker is probably rated 120 volt, and I should be using the 120 volt tap on the ballast.
The breaker seems to be tripping instantly, and usually resets fine. It is also an intermittent problem. This area has gas heaters, so I'd describe it as very dry.
I'd say change the circuit to 240v, 2 pole breaker, although your wire colors may be wrong if it's black and white in conduit. 6 fixtures at 400W will be too much for a 120V 20A circuit. You should calculate at 125% since those lights will be a continuous load. No matter what, using a single pole breaker for the 208V high leg is not correct.
Re: MH High-Bay Lights#49615 03/13/0509:11 AM03/13/0509:11 AM
Maybe golfjunkie and CRW could suggest another use for the 208V tap on this multi-tap ballast?
I used this tap to bring the current from 19A to 11A. If changing the breaker to one rated for 213V, or rewiring to the 240V tap is the solution, that's simple enough. I was curious if anyone else had this experience, especially as I have four other lighting circuits set up this way with no such problems. I should mention also that these tripped more on installation than they do now, and one of the units self-destructed. I was wondering if one of the lights would cause this.
BTW, it's an instant trip when throwing the switch. I'll take some current measurements this week. A fuse at each light would be a great way to troubleshoot an individual light, but these units are difficult to get to after installation with machines or racks.