Arrisun 12 HMI Light

Alberto Larios-Saavedra · February 9, 2006

I just purchased a used Arrisun 12 light from Visual Products and received it yesterday. I was testing the light today and it went out. This is my the first time operating an HMI light, so I'm a little worried.

Before operating the light, I read the general operating procedures for HMI lights in the Set Lighting Technician's Handbook. So I followed the instructions, turn the light on and leave it on for about five minutes. Everything is fine. Turn the light off. Wait about 3-4 minutes to restrike (at this point I didn't unplug anything nor touched any other buttons other than the "Off" button on the ballast). I then push the "On" button, the light makes the sparking sound it made the first time, but it doesn't turn on anymore and everything went dead.

Did I do something wrong? I checked the globe and it seems that it indeed burned out (the middle filament is broken). If the globe is bad, will the "Off" switch light up when the ballast is plugged in?

I hope my question is not confusing (I tried to be as clear as I possibly can).

Thanks.

February 9, 2006

did you wait, and wait some more, and then try again?

Alberto Larios-Saavedra · February 9, 2006

did you wait, and wait some more, and then try again?

Yes, I waited about another 20 minutes before trying to turn it back on and nothing.

Andrew Alward · February 9, 2006

Once you start an HMI, you can't turn it off, and then turn it back on, because you won't beable to turn it back on. Even within 20 minutes. It takes a long time for those lights to refresh so you can restrike them.

Sometimes you can get a faulty ballast.

Does the red "On/Off"(not the breaker) switch on the ballast light up when you have everything hooked up? If it doesn't, then it might mean a bad power connection to your ballast. In my experience so far, I have found those connections to be quite fragile.

Edited February 9, 2006 by Tinman84

David S. · February 10, 2006

Check the fuse on the ballast. That might have went.

Make sure head cables are still fully attached

Most importantly, make sure the front face of the lamp is closed tightly, I'll bet this is the problem. All HMIS have a micro switch that prevents the light from turning on if the door and latch are not properly in place. The first time it didn't work is because the lights don't hot restrike and need time for the globe to depressurize. Is it a magnetic or electronic ballast?

Alberto Larios-Saavedra · February 10, 2006

Check the fuse on the ballast. That might have went.
Make sure head cables are still fully attached

Most importantly, make sure the front face of the lamp is closed tightly, I'll bet this is the problem. All HMIS have a micro switch that prevents the light from turning on if the door and latch are not properly in place. The first time it didn't work is because the lights don't hot restrike and need time for the globe to depressurize. Is it a magnetic or electronic ballast?

Thanks David. It's a magnetic ballast. I'll make sure the front face is tightly closed. How can I check the fuse? Like I said, this is the first time I use an HMI light fixture.

timHealy · February 10, 2006

Like someone mentioned you will have trouble re firing a hot HMI. You get a sound similar to a light striking and glass breaking.

First HMI's don't have a filament like tungsten. When an HMI fires it creates an arc between the electrodes that create the light. But one should check the condition of the bulb glass and ceramic base to make sure it visually looks good. The glass on the bulb should look clear when new or reasonably clear when used.

The best way of re firing a hot light is to open the door that allows you to change the bulb and let it cool faster and just try it again in a few minutes.

If that doesn't work

Make sure the switch on the head and ballast is on.

Make sure you have the right voltage on the power.

Make sure the bulb it seated and connected tightly (do this with the header unpluged)

Make sure the header cables are attached securely

Make sure your ballast has power lights and the breaker is on.

Then fire said light.

If it still doesn't fire change the header cable.

If that doesn't work try the micro switch. Many HMI's have a micro switch that the UV glass presses on when the door is closed. NO glass usually means no door is closed and it is unsafe to use. You can open the door and depress the microswitch with your finger then fire the light with you standing to the side and no one in front of the light. If it strikes now then you just need to turn the plunger of the switch to a different height or length. So turn off the light, fix, close door and fire again to make sure you did it OK.

If that doesn't work you may need another light just like it to swap out parts until you find the part that doesn't work and send it out for repair.

And by all means remember to use your head and unplug and disconnect the light when working on it. I can never say that enough! If your working with someone wait for them to take their hands out of the head before plugging back in and or firing the light.

Good luck and be safe.

Best

Tim

Mario C. Jackson · February 11, 2006

Make sure that you didn't blow fuse in the house when you turned the light on

Mario Concepcion Jackson

Mike Hall · February 13, 2006

Al, you have a couple of things going for you. First, Visual Products has a great reputation, and I doubt you will have trouble with them. Secondly, you have purchased one of the most bullet-proof lights as far as HMI lighting goes - the Arri 1200 with magnetic ballast.

It sounds like you may have either a burnt out bulb, or one that has become unseated. I have seen old bulbs strike "one last time", and I have seen HMI bulbs that have been shipped in a head burn out if they had a rough trip. I imagine you purchased this light used, and it was shipped to you? Was the bulb A) New or Used, and B) Was it shipped inside the unit, or did you put it in? If you put the bulb in yourself, did you use an alchohol swab to clean the bulb before burning it?

I think you should, along with the other things that have been suggested in these posts, try a new bulb in the unit. I would bet it will solve your problem.

If you examine the old bulb (disconnect the power, and the head cable) and see any cracks, bubbles, or the bulb looks to be mis-shapen due to a heat flare, do not continue to use the bulb even if it strikes. It is possible, however unlikely, that the bulb could become unstable and explode, which will be a mess.

If you put a brand new bulb in the unit, and it buzzes but will not strike, then it's time to have the unit looked at by a qualified repair tech. Probably an igniter at that point. I cannot remember if the Arri magnetic ballasts have a dimmer, however if they do, try striking the lamp at full power or 100%, and work that knob back and forth a couple of times. Do not, under any circumstances, take the cover off of the ballast and tinker with the workings of the magnetic ballast looking for the fuse, etc. even if the ballast is unplugged.

The ballast off switch will light if the ballast is plugged in - even if the bulb is bad.

Hope you have it solved by now, and if not, I hope this helps,

Mike Hall

Glendale, AZ

Dimitrios Koukas · February 13, 2006

Did I do something wrong? I checked the globe and it seems that it indeed burned out (the middle filament is broken). If the globe is bad, will the "Off" switch light up when the ballast is plugged in?
I hope my question is not confusing (I tried to be as clear as I possibly can).

Thanks.

HMI's dont't have a middle fillament it's an arc that is created between the pins....

But yes, maybe your bulb have reached it's operational limits.

If you can see the switch lights on, both in the light and the ballast then the light should be on.

Otherwise it's either the safety switch that's on the fixture case as other fellows here mentioned, or a fault ballast.

Dimitrios Koukas