# HPS lamp in a MH fixture.



## Ima Hack (Aug 31, 2009)

Will a high pressure sodium lamp work in a fixture that has a metal halide ballast? 
I have a project coming up where the customer claims they have 20 older cans that are supposed to be metal halide but were re-lamped HPS at some point.
I've never seen it done, I didn't think it would even light.


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## 480sparky (Sep 20, 2007)

No.

HID lamps & ballasts are a matched set.

There are some combinations that will operate for a while, but it ends up in the failure of one component.


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## Grimlock (Aug 4, 2009)

480 got it, you must match lamp to ballast. Usually a miss matched lamp that ignites has a short life.


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## 480sparky (Sep 20, 2007)

Usually, for the lamp at least, it's a matter of open voltage at the socket.


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## itsunclebill (Jan 16, 2007)

There are lamps on the market that are sodium types designed to be installed in metal halide fixtures

http://www.1000bulbs.com/150-Watt-HPS-Conversion-Lamps/

Here's a link to one type


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## Mastertorturer (Jan 28, 2009)

Well if you have a job wouldn't that imply that it in fact did not work? 

Funny but I've had a co-worker try and tell me that using a 277v ballast for 208 volts would work and is ok. Uh it sort of works but is it ok? Hell no. I just shook my head and walked away. 

Choose the correct device for the intended purpose. It's not a friggen Mr. Patatoe Head. :laughing:


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## Paulusgnome (Mar 28, 2009)

MH lamps usually require a lower-voltage ignition pulse to start than HPS - around 800V for MH, and over 2KV for the HPS. If the fixtures have universal or HPS igniters fitted the lamps will at least ignite, but the lamp run current will be all wrong, and as others have said, this will shorten the life of the HPS tubes.
Conversion lamp tubes are the way to go.:thumbsup:


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## Grimlock (Aug 4, 2009)

itsunclebill said:


> There are lamps on the market that are sodium types designed to be installed in metal halide fixtures
> 
> http://www.1000bulbs.com/150-Watt-HPS-Conversion-Lamps/
> 
> Here's a link to one type


Yes, but you are still matching lamp to ballast. The lamp says it can work in a specific type of ballast.


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## PositiveBalance (Nov 25, 2009)

I have not seen MH Ballast power a HPS lamp, but I have seen an entire parking lot full of light standards with 400w hps ballasts firing 400w MH lamps for a few years since the complex was built. The GC must have got a deal on the cheap cast standards he purchased. 

As mentioned though, "making it work", and having it installed right are two different things.


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## eddy current (Feb 28, 2009)

Mastertorturer said:


> Funny but I've had a co-worker try and tell me that using a 277v ballast for 208 volts would work and is ok. Uh it sort of works but is it ok? Hell no. I just shook my head and walked away.


I have a customer that has a lot of 208v exterior lighting. We use "quad-tap" ballasts as opposed to "tri-tap". The quad's have 120, 208, 277 and 347 volt leads.


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## eddy current (Feb 28, 2009)

Ima Hack said:


> Will a high pressure sodium lamp work in fixture that has a metal halide ballast?


Just curious, most customers want to go from HPS to MH. Why do they want to go to HPS?


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## JohnJ0906 (Jan 22, 2007)

Mastertorturer said:


> Choose the correct device for the intended purpose. It's not a friggen Mr. Potato Head. :laughing:



:laughing:

You should make that your signature line. :thumbsup:


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## Ima Hack (Aug 31, 2009)

Mastertorturer said:


> Well if you have a job wouldn't that imply that it in fact did not work?


Well they are working, thats the odd thing. They have the blueprints from 15 years ago and the fixture schedule calls for a MH can, but it's without a doubt an HPS lamp. I haven't had a chance to open one up yet to peek at the ballast.


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## Ima Hack (Aug 31, 2009)

eddy current said:


> Just curious, most customers want to go from HPS to MH. Why do they want to go to HPS?


Actually they want to go MH. They want the whiter light.


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## 480sparky (Sep 20, 2007)

eddy current said:


> Just curious, most customers want to go from HPS to MH. Why do they want to go to HPS?


It could be strictly a financial decision. If I remember correctly, HPS has a higher lumens per dollar then MH.


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## Ima Hack (Aug 31, 2009)

480sparky said:


> No.
> 
> HID lamps & ballasts are a matched set.
> 
> There are some combinations that will operate for a while, but it ends up in the failure of one component.


Thanks for the chart 480, very handy.:thumbsup:


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## 480sparky (Sep 20, 2007)

Ima Hack said:


> Thanks for the chart 480, very handy.:thumbsup:


I stole it out of Advance Transformer HID troubleshooting book.

Click here if you want a copy of it.


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