The power supplies are Strong switchers and will accept either single or three phase power. We wired them in single phase and used the third phase on the breaker to power the exhaust fan on the roof in order to idiot proof the exaust fans.

We're going to pull an additional wire and connect all three phases on Tuesday. Will this solve the problem?

Question #2: Can I share one of the phases with the exhaust fan to maintain the the certainty of the fan running when the lamp house is powered up?

The power supplys already provide plenty of current in the single phase configuration, but I was told that running them this way could increase the potential of AC ripple hitting the lamps.

Even if I had an occasional "loss of cooling" melt down, it would still be cheaper in the long run as opposed to getting about a third of the rated time out of the bulbs.

As for ripple, unlike standard power supplies working at 50/60 Hz there should be practically zero ripple voltage as the high frequency AC, after rectification, is much easier to filter than 50/60 Hz...

As far as the mis-ignition goes, the lamp ignites, produces very little light, and draws about a third of the recommended current.

If you look at the arc through the filter, it is dancing all over the quartz envelope instead of between the cathode and anode.

Re-striking always fixes the problem, but the audience sees this too.

We are striking the lamp at "start plus seven seconds" and not using the change-over dowsers because they have a nasty habit of closing and staying closed when the power blinks.

We have eleven screens, but five seperate projection booths.

The 2k lamps strike instantly. The problem is isolated to the 4k lamps.

 |  IP: Logged

 |  IP: Logged

 |  IP: Logged

Lamphouse is Strong Super 80

 |  IP: Logged

 |  IP: Logged

 |  IP: Logged

If there's been an issue with Switchers, it's reliability. Putting that aside for a moment, when they work they work very elegantly, and they really do work the greatest majority of the time. The advantages are, of course, light weight, very high power efficiency and ideal power characteristics for a xenon lamp.

There is virtually NO AC ripple on the output of the Switcher -- <.5%. Darkening of lamps is a contamination issue and won't be affected by ripple, unless it's really, really high, to a point where you couldn't watch a projected image on screen. Excessive ripple will cause the anode to develop bubbles and high spots, and the cathode tip will round off or crack very quickly. One problem you won't have with switchers is ripple.

The Switcher has very low inrush characteristics during the ignition cycle. Inrush is around 150% or less of the nominal current, compared with 250-300% or more from many magnetic (brute force) supplies. That's one feature, along with the low AC ripple, that promotes longer lamp life.

The output of the system is "tailored" to produce an "ideal" power characteristic during ignition to make it more reliable. One challenge in this is the different lamps -- an ORC 2kw acts differently from an Osram. Heck, there are variances in the same lamp designs from the same manufacturers. Lamps age differently and the arc gap varies with age. They have slightly different fill pressures, different mix of thorium and tungsten in the electrodes, etc. As some of these designs and specifications have changed and varied over time, we've tried to cover those changes with modifications in the Switcher.

ALL lamp manufacturers have tested Switchers at various stages -- we've sent them just about everywhere for analysis and have worked closely with Osram and others in many instances.

I know I've encountered many more instances where a Switcher will light a lamp better than a standard supply could. In some testing I've done (tests unrelated to this topic), I've struck and run 2kw lamps at 15A -- the switcher will ignite them and maintain a steady arc even at that low a current setting. This is a special circumstance and not necessarily good for the lamp, but the Switcher will do it more often than not.

You are correct about lamp life. Our 2k average lamp life jumped off the scale when we converted to switchers. The things paid for themselves.

Single or three phase for 4000 watts?

 |  IP: Logged