Quartz Restrike vs. Pulse Start HID's

[birddogger]

Can anyone help me in explaining the pros and cons of quartz restrike vs. pulse-start ballasts on HID lighting? The way I understand it, quartz restrike provides immediate low-level illumination during the HID's re-lamping period following a power outage via a separate quartz filament, while pulse-start ballasts essentially "shock" the HID lamp such that it re-lamps much quicker.

I would think that quartz restrike would be cheaper, more reliable, and would achieve the desired goal (immediate light) quicker than pulse-starts, which seem to be bulkier, more expensive, yield shorter lamp life, and still don't produce sufficient light as quickly as the quartz restrike. Don't pulse starts still take a matter of minutes to reach full illumination?

Thanks in advance!

 

[mpparent]

Even with pulse start lamps, you still have a restrike time. While it may be a shorter time frame, I personally think having quartz restrike is a good idea. Additionally, pulse start lamps have a longer life than standard metal halide lamps, and a larger lumens/lamp. I think I recall a 150W MH lamp was equivalent to a 250W (lumens), but I might be mistaken on that. You could always go to Sylvania's website or Philip's and take a look yourself.

Mike

 

[mc5w]

However, the quartz bulbs are expensive and have short life. One option is to use auxiliary fluorescent fixtures that use a time delay relay to shut off after a certain amount of time.

What would be simpler would be to get say 1/8th or 1/4 of your illumination from the fluorescent fixtures and the rest from the metal halide. This would allow you to get rid of the auxiliary relay. There is nothing that says that you MUST use only one light source and using auxiliary fluorescent may actually simplify metal halide fixture spacing.

That said, I have found that apertured reflectors for fluorescent fixtures allow MORE dirt to fall on the bulbs than nonapertured reflectors. You are better off to illuminate the ceiling by bounching the light off of the floor or with the light that leaks out the top of an open metal halide fixture reflector.

Mike Cole, mc5w at earthlink dot net

 

[birddogger]

Thanks for the responses so far. I have to add though, that this is for a food processing plant, so pendant hung flourescents would not be practical. NSF-certified HID's are the way to go, I just need to justify to the client why we should use quartz vs. pulse-start. On a previous job (not designed by me), I noticed some fixtures in the schedule that had both quartz restrike and pulse start. To me, that's overkill, but perhaps someone knows the method to the madness there.

 

[mpparent]

As I said, quartz restrike is only used for the time that the pulse start lamps get to temperature and are at full intensity. Then they turn off. It's only to provide a measure of lighting until the MH lamps are up and burning. You don't use quartz restrike alone.

Mike

 

[hbendillo]

Venture Lighting is probably the best place to go for information on pulse start characteristics for metal halide lamps. The pulse start does produce a measure of light almost immediately but you need stats from the manufacturer to determine if it is enough for egress lighting. Depends on how many fixtures, mounting heights, locations, etc. What kind of emergency system do you have? Battery Backup? Generator?

 

[birddogger]

I realize that quartz restrike is not a stand alone feature. It just seems to me that quartz restrike would provide sufficient illumination during the HID's relamping period, and that supplmenting it with a pulse-start ballast would be overkill. It would seem that one or the other should do the job.

I already have battery packs for emergency lighting, so this is not an egress issue. It is only for resuming illumination after a power outage to resume production.

 

[mpparent]

The pulse start ballast is only for the MH lamp, it has nothing to do with the quartz restrike lamp, other than an auxiliary module that wires into the ballast and the pulse start lamp.

Here's an example:

http://www.thomasresearchproducts.com/PDFFiles/ESP125TFeb2005.pdf

Mike


PS Pulse start is available in HPS, but I think it's not as commonly used.