UV Cannons into dimmers

[SceneMaster]

UV Cannons into dimmers.

 

 

I am working on a show with some other people (armature show) doing lighting and we have hired some UV cannons. I was there for most of the get-in yesterday and then had to go of to proper work (a pro theatre). I had specifically said the UV must be hard powered.

 

Came back this evening to find the dimmers hard powered but was told that they seem to cut out after 3 mins, which bemused me a little but I said I would take a look later. On the way home tonight I was chatting to one of the guys who said that originally the UVs were on the sound feed and it tripped (not surprising with 1600watt of UV cannon and a hell of a lot of sound which I know nothing about for this show so couldn’t comment on the power being used) so they though they would put them on the dimmer on 100 programmed from a cue to go from 0-100 snap. At this I just went ohhh… as I am pretty certain that UV cannons don’t like being on dimmers and I presume this is one because they are florescent type lamps and two that the cannons possible have some circuitry in them (do they I haven’t really ever used one or taken one apart).

 

Anyway basically what I am asking are the UV cannon's circuitry (or just the lamps) now screwed from being on dimmers?

 

Thanks,

[Ynot]

The short answer is NO, NO, NO and once more, NO!!

UV cannons are NOT to be controlled by dimmer channels! I'd recommend not even loading on a switched dim circuit (which sounds like what they've done).

 

TD

[Guest lightnix]

I always thought it was the dimmers that suffered the most

 

UV Cannons are inductive loads and there's quite a good post from Brian on a related subject here.

...Some dimmers do not like the current to be out of phase with the voltage, it stops them working. A triac in a dimmer (the bit which controls the power) needs a current flow to stay on, if the control circuit is looking at voltages to decide how much power to let through it can get confused...

[Mush]

UV Cannons into dimmers.

 

Anyway basically what I am asking are the UV cannon's circuitry (or just the lamps) now screwed from being on dimmers?

 

Thanks,

 

Guessing from your description of 1600W of UV cannons that your using 4 off 400W mercury lamps?

 

High pressure mercury lamp is bit more complex than filament lamp and does have an inductive load in shape of ballast, other unpleasant thing from a dimmers point of view is switch on surge as lamp strikes.

http://www.lamptech.co.uk/Documents/M1%20Introduction.htm

 

http://members.misty.com/don/dschlamp.html

 

http://www.venturelighting.com/TechCenter/...tTechIntro.html

 

The way you say they started cycling also sounds as if the ballast may be getting hot in the lantern and thermally cutting out.

Dimmer set to 100% does not behave totally like a closed switch.

[SceneMaster]

The short answer is NO, NO, NO and once more, NO!!

UV cannons are NOT to be controlled by dimmer channels! I'd recommend not even loading on a switched dim circuit (which sounds like what they've done).

 

TD

 

Ok... I know they don't go on dimmers I am not stupid I wasn't even thinking of putting them on dimmers what I want to know is once the cannons have been on dimmers is the lamp/cannon now screwed and either the lamp will need replacing or the cannon. They are not working well on the hard power as in they strike and power up then cut a few mins later on there own... and quite frankly I am a little annoyed that they were put onto dimmers in the first place.

 

Thanks so far...

[timmath]

I have had no issues 400w UV Guns, on ART 2000 dimmers, one per chanel with a 300w sun flood as a dummy load. Make sure you set the dimmer controller or desk to make the channel switch not dim though.

 

I'm not saying they will run happily on everything but on the Avo's they appear to be fine.

 

Regards

 

Tim