Sensing of Lamp vs. Ballast Failure (MH)

[peebee]

Is anyone aware of any good/feasible method to sense lamp failures and ballast failures for metal-halide fixtures (sized anywhere from 70w to 1000w), including discrimination between which one has failed?

I've heard rumors that a CT in the input of the ballast may be sufficient, either to measure ballast input current magnitude or phase angle. I've heard that two CT's may be required, one on the input and output of the ballast. I've heard that neither method might work. And I've heard that a capacitor failure could falsely read as a lamp failure.

Does anyone have experience with this? Does anyone know of vendors that can provide such a monitoring system? Is anyone aware of ballasts which come with internal cicuitry to alarm on ballast vs. lamp failure? Are there any other potential solutions that perhaps I'm overlooking?

 

[rbulsara]

peebee;

I am not lighitng expert. But have looked after plants in my past life.

Since I did not see any response, here is my 'alternative'.

How about keeping a spare fixcure of its kind, or few sapre ballasts and lamps of each kind in your installtion.
Then try changing a lamp first (simpler of the two),if it works then lamp is bad. Failing that change ballast, place old lamp back in, if it works then ballast is bad. or Both.

If this is in warehouse type setup, you can simply chang out the defective fixture and play around with malfunctioning one in the shop.


I am sure you have tried this or tired of this.

Good luck.

 

[peebee]

Thanks, rbulsara. But yes, I'd thought of that one. . . .

The problem with this installation is that the ballasts are remote mounted, and it takes quite a bit of time to travel from the fixture to the ballast. It would be a tremendous maintenance savings if they knew right where to go to get the fixture working again.

Stragely, this would seem to be a simple enough system. But apparently it's not quite as simple as it seems.