[Jere]

Hey all,

I ran into an issue on the weekend while replacing some bulbs on the outside of our riding arena. The north facing wall has 4 x 400w Metal Halide wall packs on the outside. The fixture closest to the rear shares a 15amp circuit with a 175w Metal Halide wall pack on the west facing wall. Nothing else shares the circuit with 2 fixtures. I replaced the 175w bulb , burnt out months back, on the weekend and once the 175 reaches it's full brightness both the 400w and 175w bulbs go out and after the typical rewarmup cycle period, poof out again. Circuit breaker never trips during this. I removed the 175 bulb and the 400 is operating normally again. These are not switched fixtures, they are photocell activated wired directly to panel. Is one of the ballasts shot? I Would think that would only affect the individual fixture and not both?

Thanks,

Jer

 

[AllanJ]

Does the light of the 175 watt lamp shine into the photcell?

Put tape over the photocell and wait five minutes. Do the 175 and the 400 sharing the circuit come on and stay on?

Also measure the voltage as the lights warm up (at the lights, not at the panel).

(Most lighting photocells do not act instantly in order that brief bursts of light such as from passing car headlights do not make the lights go on and off.)

 

[frenchelectrican]

Either you have weak photocell or the light reflection to hit the photocell one of the two most common cuprits.

Do you have button photocell or the swevil type or standard twistlocker type if swevil or standard twistlockers you can able rotate to reduce the stray light hit the photocell.

For the button type you may have to make a tunnel effect to reduce the amout of light to hit the photocell unless that housing or something can be rotable.

Oh yeah just don't get too small a rating of photocell those HID can be pretty hard on the photocell if not watchout. { I doubt it due you only have two HID's on that one }

Merci.
Marc

 

[Jere]

Thanks for the quick responses guys, I appreciate it..

No light from either fixture reaches the other one at all. I'm going to take the voltage measurements this evening and I'll get back to you tonight.

Thanks,

Jer