H I D lamp swapping; lamp questions

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thunder15j

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I've been wondering if metal halide lamps can be interchanged with mercury vapor lamps; wattages would have to be the same ; output voltages would have to be the same.

How about putting a MV or MH lamp in a HPS ballasted fixture. You would have to disconnect the ignitor, match wattages, and voltages. I think that lower wattage HPS usually runs at 55 volts and higher wattages at 110 volts. I,ve never measured secondary voltages of MV of MH.

How about clear verses coated lamps in all HID types. Seems like clear is typically for exterior lighting and coated for interior.

Also has anybody seen metal halide lamps that blow/break apart in a fixture? Came across that situation in a few enclosed fixtures on a call the other day ( they were 175 watt medium base wall packs). I think that in open metal halide (multi vapor) fixtures that one should use a lamp that is rated for that application, if a lamp is indeed made for that useage. Or are there some bargain priced lamps out there that just blow apart?
 
To the best of my knowledge you can swap metal halide lamps for mercury vapour lamps only if the ballasts are rated for such. The newer ballast will support both lamps but the older ballasts may not.
I would never dream of using metal halide lamps in HPS ballasts but they do make lamps now that work in HPS ballasts but have the colour of metal halide.(only in higher watages)
In my opinion clear versus coated is something that only lighting engineers pay attention to. In my experience one is interchangeable with the other. The slight differences are hardly noticeable and it saves stocking two different lamps on your truck. Also there are slightly different light outputs from the two different lamps.
I have seen metal halide lamps blow apart. Sometimes for no apparent reason. I do think that in fixtures that operate 24 hours a day it is recommended by the manufacturers that they get cycled off once every 24 hours?
 
As the company I work for has to honer warranty work for one year I really do not use any lamp not directly listed by the ballast.

Yes some of the lamps can be interchanged but I have no time to stop and look up which ones can be interchanged.

What is the up side to switching lamp types?
 
a metal halide ballast can use a mh or mv bulb, but a mv ballast can't use a
mh bulb only mv bulb. speaking to lighting people in the past the 175 watt
mh med. base bulb was referred to as the dog of the industry. it has to be shut down for atleast 15 mimutes in a 24 hr. period. i service parking garages that use the 175 watt med. and on my monthly service i will always find 1 or 2 of the fixtures that the bulb has exploded {garage has fewhundredfixtures}.
a little trick on testing hps fixtures when the bulb is out to see if the ballast is good is to use a incondescent bulb of the same wattage { for test purpose
only} if the bulb lights then it's not the ballast.
 
thunder15j said:
I think that lower wattage HPS usually runs at 55 volts and higher wattages at 110 volts. I,ve never measured secondary voltages of MV of MH.

The secondary voltages vary by type and wattage.

For example

A 35 watt HPS ballast should have an open circuit voltage between 114 and 126 volts.

A 400 watt HPS ballast should have an open circuit voltage between 170 and 255 volts.

A 1000 watt HPS ballast should have an open circuit voltage between 395 and 485 volts.

You can find anywhere from 100 to 800 open circuit volts at the lamp socket depending on the lamp type and size.
 
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