# Metal Halide and outside cold temps



## wcord (Jan 23, 2011)

Guys
I have one for you.
We installed a group of Architectural MH 175 w fixtures, made by a reputable manufacturer. 
The first cold winter (-20 C min) we were getting failures.
Bear with me as I explain.
Day 1 lets say 2 out of 12 will come on.
Day 2, those same 2 may come on and a different set of fixtures will not work.
And so on 
It seemed that every time the fixtures were energized, a different number of fixtures would not work.
And it didn't matter if the fixtures were at the beginning or end of the circuits.
Two years later, for the same customer on a new building on the same lot, we installed identical fixtures. Guess what? Same problem!
Now we sent 2 fixtures back to the factory, where they were subjected to whatever their engineers dreamed up. The factory changed the insides and returned them with a few spare capacitors.
The "repaired" fixtures failed again.
Changing bulbs helps somewhat but within the year, we are back to square one.
Once the fixtures start this cycle, they continue to fail in the summer, although not as often.
Failure can not be heat related as summer has less failures than winter. High humidity doesn't seem to be a factor either
I tried to post a picture but failed.
Since the manufacturer has been very accommodating, I dont have regrets of naming the model. It's a Rab WPQ

So any ideas???


----------



## HARRY304E (Sep 15, 2010)

wcord said:


> Guys
> I have one for you.
> We installed a group of Architectural MH 175 w fixtures, made by a reputable manufacturer.
> The first cold winter (-20 C min) we were getting failures.
> ...


Maybe Jesus was a carpenter, but God was an ELECTRICIAN - Let there be light:thumbsup::laughing:I like your signature .

Are the ballast electronic or magnetic..?


----------



## wcord (Jan 23, 2011)

magnetic with cap


----------



## HARRY304E (Sep 15, 2010)

wcord said:


> magnetic with cap


 MAG Ballast that is a plus..so the lamp wattage is exact to the ballast spec's ? How about the lamp brand? What voltage are you using?|
Is the ECG good?

RAB is top noch IMO so they may have been hit with a bad batch of ballast 
I have foud there lighting fixtures to be long lasting with very little trouble..


----------



## wcord (Jan 23, 2011)

Lamps are matched to the ballast.
Phillips lamps
Don't know what you mean by ECG. But my doctor told me my heart was excellent
Voltage drop within 3%
Splices have been double checked
Rab bent over backwards to try to find the problem.
And yes, Rab has an excellent reputation up here too.


----------



## HARRY304E (Sep 15, 2010)

wcord said:


> Lamps are matched to the ballast.
> Phillips lamps
> Don't know what you mean by ECG. But my doctor told me my heart was excellent
> Voltage drop within 3%
> ...


 Equipment ground conductors..should have been EGC.

Try sylvania or GE metal halide lamps..


----------



## frenchelectrican (Mar 15, 2007)

Can you expand this part little more is this MH is probe start or pulse start 

I know probe start useally flutters a bit when it hit -25°C but pulse start they will really lit up cold as -40°C { right on the par with HPS } 

Some case you have to change bulb manufacters to see if that slove it.

I useally use Sylvain lamps but Phillips are ok to moi .

Merci.
Marc


----------



## MDShunk (Jan 7, 2007)

Some RAB fixtures would only work with Venture brand lamps. I have no explanation.


----------



## wcord (Jan 23, 2011)

probe start


----------



## frenchelectrican (Mar 15, 2007)

MDShunk said:


> Some RAB fixtures would only work with Venture brand lamps. I have no explanation.


Thanks for bringing it up and Oui.,, I did recall the same situation you have before.

Merci.
Marc


----------



## frenchelectrican (Mar 15, 2007)

Did you use the universeal bulb AKA all postion bulb which it will have a letter " U " on the bulb if that the case you may want to change to either Horzontal postion bulb or base up or base down verison some case it will do the trick due the way the arc tube change a bit on them.

Merci.
Marc


----------



## HARRY304E (Sep 15, 2010)

MDShunk said:


> Some RAB fixtures would only work with Venture brand lamps. I have no explanation.


 The only thing i can think of is their ballast's are made for that exact lamp.


----------



## frenchelectrican (Mar 15, 2007)

HARRY304E said:


> The only thing i can think of is their ballast's are made for that exact lamp.


It is the same situation with some Ruud luminaires as well few did speced with Venture lamp as well which I found out in hard way even thru the ballast did have ANSI #'s stamped on the ballast only once it got me off gaurd on it.

Merci.
Marc


----------



## HARRY304E (Sep 15, 2010)

frenchelectrican said:


> It is the same situation with some Ruud luminaires as well few did speced with Venture lamp as well which I found out in hard way even thru the ballast did have ANSI #'s stamped on the ballast only once it got me off gaurd on it.
> 
> Merci.
> Marc


 Yes it is sneeky..


----------



## frenchelectrican (Mar 15, 2007)

Wcord ., I will suggest that you should check with Ventre lamps if you have them in your area I think that should take care the issue with it espcally with base down verison.

Merci.
Marc


----------

