dimmable fluorescents

[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!

[cmchamp]

You probably have either halogens or sulfur if you're in a gymnatorium. I'd speak with your local electricians to see what they have available.
C.

[RonK]

Here in the states there are 3 basic types of dimmable fluorescents, 2-wire, 3-wire, and 4-wire. All require a special dimmable ballast, and for most a specialized dimmer.
The 2-wire can typically use a standard SCR/SSR dimmer (i.e in a dimmer rack, not a rotary wall dimmer) with a dimmable ballast. The performance is not so great - the lights tend to flicker as they dim up or down and they only dim to about 20% before they turn off.
The 3-wire dimmable ballast uses one constant hot-wire (on/off only) in conjunction with a dimming hot wire (plus a neutral) performance is a little better than the 2-wire. Each fixture requires 2 circuits in the dimmer rack.
The 4-wire ballast uses a hot circuit (2 wires) plus a control signal circuit (2 more wires). Requires a special dimmer rack like the ETC Unison for the control signal. PErformance is pretty good, the dimming curve is fairly stable and they will dim to about 5% before turning off.
There is a newer digital type also that I'm not too familiar with.
In general the performance of any dimmable fluorescent will never match incandescent, but if energy savings or heat are the issues, they can accomplish the goal.

[RonK]

You probably have either halogens or sulfur if you're in a gymnatorium.

PS Gym lights are typically mercury vapor or high pressure sodium. Halogen refers to a type of incandescent (and dimmable) lamp.

[cmchamp]

Thanks RonK. Unfortunately, for some reason, my brain is fixated on the reasons why the bottom of my coffee cups from PS Foodmarts have been leaking for the past week.

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.

[RonK]

No worries Cory...I'm a lighting guy by trade, but just this week taken over the sound position at my church (for the sound guy who's moving to Hawaii of all places)....so I promise to have PLENTY of audio questions for you real soon.

Good luck with your coffee cups

[Esoteric]

Yeah, I never dim fluorescent lights unless I absolutely have to. It is usually easier/cheaper/better just to replace them.

Mike

[millamber]

I've attached a pdf of a file written by one of the guys at ETC that is the best explanation of the different types of florescent ballasts and how to deal with each I've come across.

Hope this helps.

[zactommo]

mercury vapor, they are the ones we've got.

The current setup is four rows of 5 of the mercury vapour lights. The are wired in parrellel, with the 3 core wire going into the back of one, and then on to the next. Do these lights work in a parrellel config like that, or does each fixture need its own dimmer/balast thing? Are these fixtures using specific bulbs too, or just standard bulbs?

Also, does anyone know what sort of range of light colour you can get with fluorescent fixtures. I know that these consumer "energy saver" bulbs you can buy, you can get ones that give out a warmer coloured light, more like an incandescent fixture, or the standard, very cold white light. Does the same sort of range exist within fluorescent tubes?

[Gracetech]

I'm installing more and more dimmable fluorescents(something i couldn,t say just a couple of years ago). Fluorescents now have the ability, with the correct ballast, to dim to 1% with any dimming method. I've used CFL's entirely to light some churches, but those CFL's only dimmed to 10%. I'v recently checked out some new CFL technology that dims to 5% or less.

As for the color temp of Fluorescents they usually come in three varities. Cool which is 5.6k to 6k and white which is around 4k to 4.4k and warm white which is around 3.2k to 3.6k. The cool thing about fluorescent is that the dimming color shift is almost nonexistent compared to incandescents.

Now you have to watch out for cheap dimmable ballast but the quality ones are great.

BTW a new tech in the lighting world to keep an eye on is the Plasma tech. I'm still waiting on a review sample to see how great it is but the feature set is amazing.

crt

[Esoteric]

Plasma isnt quite there yet. It is where LED technology was 3-5 years ago. But Robe is right on the cutting edge.

Mike

[Gracetech]

BTW here is some info on the Plasma tech.
http://www.lifi.com/dynamic/display.php/48

The key advantages are Color rendition which is 95(awesome) and lumens/watt which are around 120+.

The new Rope light will produce 10,000 lumens off of 266 watts. It's always tough to get all the lumens out of the fixture(darn optics).

Oh and to top it off the life span is supposed to be around 10k to 30k hours.

crt