dimmable fluorescents

[zactommo]

Just clarifying a few things here, being that I’m no installation lighting expert.

The ballast controls the starting of the lamp, and in this case, the correct dimming. Are ballasts required, per lamp, per fixture, or per circuit. So we will probably being using the fixtures that fit into one tile of a suspended ceiling, with maybe two or three lamps per fixture. Will be four rows of 6 fixtures (I think) each row on a different switch/dimmer. How many ballast to I need.

Also, I still haven’t clarified how the dimmer for the fluros differs from a standard dimmer I would use for normal lights (or maybe you have and I didn't understand, or pick up on it)

Thanks everyone for your wealthy of expertise.

[Gracetech]

Ballast are rated by power usage volts/watts. It you have two 25watt tubes you will need a 50 watt ballast to run them so on and so forth. I can provide you with some dimable ballast manufactures if you need. The manufactures make an asortment of power sizes to fit about any project.

I don't understand your second part about the dimmers maybe you are asking what's the difference in electronic dimming vs. resistive?

crt

[zactommo]

Thanks for that, I understand what you mean about the ballasts now. In practice, where would be the best place to put the ballasts in the circuit? What is the standard way of doing things?

I dont understand the distance between electronic and resistive dimming. What is the difference, and which of those should I use for fluros?

Thanks!

[Gracetech]

Originally Posted by zactommo

In practice, where would be the best place to put the ballasts in the circuit? What is the standard way of doing things?

The balast goes between the power and the fluorescents. The way in which you attach the fluorescents depends on your application. I can't be more clearer than that. If you have a 50 watt ballast you could put two 18 watt tubes in Parallel on those taps or 3 15 watt tubes in Parallel or just one tube less than 50 watts. This is up to you. You could even put the lights in series but if one tube goes out the whole chain goes out. Some ballast have three taps which are usually hot hot neutral and it just divides the wattage of the ballast among the taps. Unfortunately there is no standard, just know your electrical or get someone that does. Be warned you will zap yourself good if you play around with ballast.

Originally Posted by zactommo

I dont understand the distance between electronic and resistive dimming. What is the difference, and which of those should I use for fluros?

The difference between resistive and electronic dimming is quite technical so let me just say that most modern dimming ballast will handle either. Of course cheap electronic dimmers will fry even dimming ballast quicker than resistive or high quality electronic dimmers.

What you are looking for is a smoothed PWM circuit. You will often have to talk to techs to get this info but if you tell me what dimmers you would like to go with i can tell you if they are a good quality.


crt

[zactommo]

Thanks again for the info.

I'm sure about brands in the US, but in NZ, pretty much everyone uses theatre light gear, as it cheapers than imported stuff, and very high quality. http://www.theatrelight.co.nz/satellite.htm
http://www.theatrelight.co.nz/moodset.htm

I was thinking of one of the ones that i've put the links to above.
I really wanted something with DMX Control, so I can have a small console on the wall to control the house lights normalls (ie http://www.theatrelight.co.nz/starlet.htm )
And then get one of those consoles that has a "house lights" section that outputs to a seperate DMX, so the house lights, and stage lights can run of the same console.

[D.R.HADDOCK]

Originally Posted by zactommo

I'm sorry if this topic has been covered already in the forums.

Basically this is the situation. Our current house lights are those horrible (can't remember the correct name right now) lights that take 5 minutes to warm up, wont turn on for 20 minutes after you turn them off, give out a horrible, very cold/ultra bright light. You know the ones.

Anyone, as you can tell by my description, I hate these lights with a passion, and I want them to go! Putting in incandescent bulbs would be nice, but it means a lot more fixtures, extra wiring etc.....

I was at a church last year, that used dimmable fluorescents. Talked briefly with the house tech while I was there, and he said they work by reducing the voltage as opposed to the current (I think). I believe it means you can't dim as dully as you can with incandescent, but it means we only have change the fixtures, and put the dimmers on the ends where the switchers were. This equals a huge cost saving!

Anyway, I'm wanting to know if anyone else uses this in their church, or can give me some more information on how these systems work. The advantages and pitfalls of these systems.

Thanks all!

Yes, i had the same problem when i first came to my church, it was originally designed to be a school gymnasium, and it had mercury vapour discharge lamps, like the ones you are describing.they had to go! so we put two 300w linear tungsten halogen lamps in the lamp fixtures. we tryed two 500w lamps first, but they created too much heat, the 300w ones seemed much cooler.
we then ran cables back to the dimmer racks, and hey presto problem solved.
dimmable house lights that dont buzz, or drop out and a much more pleasing colour from the lamps.

[[Director] Joseph B]

Originally Posted by cmchamp

Oh, and just in case someone missed it, I'm not afraid to be wrong, nor admit I'm wrong, nor admit when I don't know something.

I thought I was wrong once, but it turned out I was mistaken...

[zactommo]

Originally Posted by D.R.HADDOCK

they had to go! so we put two 300w linear tungsten halogen lamps in the lamp fixtures. we tryed two 500w lamps first, but they created too much heat, the 300w ones seemed much cooler.

So did you just replace the bulbs and use the same fixtures? I haven't had a look inside any of our current ones, so I have no idea what sort of bulb they take. Does anyone know if the stuff that controls the warm up warm down period etc is part of the lamp or part of the fixture?

[D.R.HADDOCK]

Originally Posted by zactommo

So did you just replace the bulbs and use the same fixtures? I haven't had a look inside any of our current ones, so I have no idea what sort of bulb they take. Does anyone know if the stuff that controls the warm up warm down period etc is part of the lamp or part of the fixture?

There was plenty of room inside the fixtures to mount two seperate lamp bases, without having to touch the existing discharge lamp and associatted wiring ( ballast ). The warm up and warm down are functions of the type of lamps used in discharge fixtures, when first turned on, the phosphers inside the lamp envelope have to be excited so that they glow, this can take up to ten minutes for older lamps, shorter periods for newer lamps. and the warm down ( drop out ) is a function of the re strike mechanism which is thermally operated, so the lamp must cool down enough for the restrike to occur usually 5 to 10 mins some really old lamps could take 15 or 20 mins.
with these types of lamps once they have exceeded there rated life span
they will continue to operated but light output tends to drop off and the lamps become slow and sluggish to start and restart.