Extending the life of discharge lamps

[RoyS]

Hi All,

Simple question regarding lengthening the life of some MSD/NSD 250w discharge lamps.. What would be more beneficial?

 

A: To strike once a once a day and keep the fixtures running for 6 hours..

 

B: To strike twice in the 6 hour period.

 

In both scenarios the fixtures will only be running a ‘show’ for 2 hours total. This is in regard to 4x 250w discharge profiles in a school situation.

 

Many thanks

[timtheenchanteruk]

IIRC, each strike reduces lamp life by about an hour, so if the break is greater than an hour (and they will cool enough to re-strike, you dont say what fixtures you have but some cheaper ones seem to need to be nearly stone cold to re-strike) then douse them,

 

If not leave them in the home position, it vertical, open white, shutter open to maximise air flow and reduce the chance of anything warping.

[adam2]

I suspect that B is a better option, though there are so many variables that there may not be a definate answer.

Dont forget the waste of electricity by leaving the lamps on needlessly.

A 250 watt discharge lamp lit needlessly for about 5 hours will use about 1.6KWH of electricity at a cost of from about 20 pence to about 30 pence.

In a hundred days or so the energy waste could roughly equal the cost of a new lamp, and remember that the lantern may last longer without the heat build up from needless continuall operation.

[J Pearce]

If not leave them in the home position, it vertical, open white, shutter open to maximise air flow and reduce the chance of anything warping.

 

Check your fixture, quite a few will run the lamp at half power if the shutter is closed for more than a few mins, instantly returning to full power once the shutter opens.

[niclights]

We've been here before and no one really knows. I've never seen any evidence or information from lamp manufacturers to confirm or deny if striking affects lamp life, at least not if they are always allowed to reach full power before douse and then allowed to cool before restrike.

 

Personally I tend to do two strikes per show for all the reasons Adam states (power saving/heat reduction inc. minimising wear on fixture/reduced lamp use).