Hi. I live in a 28 yr old condo, and the strata corp is thinking of installing photocell lighting along with a new timer (the current one doesn't work). In my Google searches, I keep coming up with sites saying that you usually cannot use cfl's with photocell, dimmers or timers. Is this correct? We are trying to save energy and $, and as far as I can see the best way to save is to use cfl's. Also, why would timers have an adverse effect on a cfl? The lights would go on at dusk and off and dawn. Any anwers to these questions are much appreciated!

I have a cfi light in my yard light. It has a photocell in the post installed as a separate component. It works just fine. The reason they say cfi lights won't work with a photocell they mean if you had one of those photocells that are installed between the actual light bulb and the light socket. That will cause the cfi not to work properly. Remember these bulbs take less electricity to run them. I'm not too sure as to why timers would affect cfi's but it probably has something to do with not enough electricity to properly power them I'm wondering if these people know what they are doing using both photocells and timers with cfi's. If the photocell is installed as a separate component there should be no problems as far as I can see.

Hi, and thanks for your answer; however I would really like to hear from an expert, as I'm talking about CFL's, but you are calling them CFI's, so I can only assume that you are not an expert in this field.

Thanks again. Not trying to be rude. Just in need of a qualified answer.

Certain photocells essentially act as dimmers, and the amount of current to the bulb is inversly proportionate to the amount of sunlight. This is the same as using a bulb with a dimmer so CFL's will not work. Other photocells, such as those for mercury lighting, etc, are a hard on-off and these would be OK.

Similarly some timers and other electronic switches have some leakage current that would cause CFL's to flicker, or burn out prematurely.

The best advice I can give is to the try the CFL's in the given fixtures. Note how the bulbs behave when the fixture is on, AND when it has been shut off by the timer/photocell/etc. If they work as they should, so be it.

Another reason you can't use CFL's in certain settings, they're not designed to be turned off and on a lot in a short period. So say a 5 minute timer, or a flashing fixture, etc, that could be damaging to the bulb.

Another reason, is that the load presented by a CFL can be considered inductive rather than resistive. If the timer or switch uses a solid state device rather than a relay without the approprate design, the solid state switch could fail.

Everything that Ceilingfanrepair states is accurate.

Sometimes I use a photocell and timeclock, so lights will go on when dark, and will turn off at Midnight?
So far, Don't know of anyone that makes a Dimming CFL.
They have had dimming flourescents for years, has a 3rd wire(could be brown), Dimmer also has this 3rd wire.
The last few years they have gotton down to 2 wire fluorescent fixtures(ballast)and 2 wire dimmer.
How about an LED Light, If efficiency is your goal.
You could use a relay to get solid voltage from photocell.
Like KISS was saying, They don't like solid state switching.

They do have dimmable CFL's but they're expensive.

Ceilingfan, Thanks, I found the dimming CFL's, seem to work with regular dimmers?
Intermatic has a Digital Timer, with Battery backup. So if power goes out, Time is not out of sync.

All Swylite brand timers work well with CFL bulbs. The Intermatic and Leviton timer do not work with CFL's for they control the circuit differently. They cannot sense and control the internal ballast circuitry adequately.

Ask your condo association to use the Swylite Timers. They are designed for ultra-low power bulbs (down to 1 watt) and proven to work.

Another reason, is that the load presented by a CFL can be considered inductive rather than resistive. If the timer or switch uses a solid state device rather than a relay without the approprate design, the solid state switch could fail.

Everything that Ceilingfanrepair states is accurate.

This is not true with the Swylite Timers. They are rated for use with inductive circuits, something the others are not.

Hi, everyone.
I used one of those screw-in photocell adapters which should work specifically for CFL bulbs. It does not work! At the dusk light came on. Wow! But in 1 minute came off, after came on... off... on... off. I got another one. Same story, so it is not defective adapter.
What is happening?

It sees the light, thinks its day, turns off, with the darkness, it turns on, repeat, repeat, try to aim to photocell away from the wall, anything reflective.

Nothing to reflect from. But you are right - cell thinks that it's day because of its bulb light. I talked to different people and came up with conclusion that designers produced poor design of this adapter (Westek, CID #SLC5). Photocell is too sensitive to the light produced by it's own bulb. This adapter comes with three different covers for the photocell (smaller to larger openings) but non of them works for this application.

As said above, most photocell have a minimum load & or use a solid state device which will only work filament lamps, the reason they are cheap to make. Use an Acetek photocell from the CellOptik range. These have no minimum load and use a relay so they work the CFL just like a normal light switch.

Des, Take a look at the date this post was last looked at, it is fours old. We try to not go beyond several months because generally speaking, the original poster is long gone and not seeking new information.