I'm looking for an outdoor photocell to turn lighting on at night. Anyone recommended a model? Anything I should be aware of (special features, etc.)?

FWIW, the circuit it will be switching is 20 amps (altho the draw is much lower, of course).

 

If you're switching plain incandescent lamps (inc. halogen), then any type of line voltage photocell should work fine.

If you're switching fluorescent, CFL or any other type of ballasted lamp then you'll need a photocell and possibly a relay which are designed for that type of lamp.

The photocell switch need only be rated for the watts it is actually switching, not the max of the circuit.

 

Most of the lights are incan but I was switching to 13W CFL's when the incans burned out. Right now there are 2 CFL's but there will be more and more.

Knowing this, I will need a relay? I've searched but I haven't found much. Do you know of a model/system that would work for me?

Out of curiosity, what would happen if I used a typical $15 photocell with a few CFL's?

 

They may flicker on and off during daylight. Most cheap photocells draw a small amount of current at all times. Not enough to activate an incandescent but enough to get a small reaction from a CFL.

 

Usually it burns out either the photocell or the CFL ballast within a fairly short timespan. Sometimes it just doesn't work and causes a dim flicker in the CFL.

A workaround is to have at least one incandescent lamp switched along with the CFLs. The single lamp should provide enough of a path for the photocell to work properly while still allowing you to change the rest of your lamps to CFL.

Otherwise, you need to get a photocell which is CFL/ballast rated or wire up a relay.

 

I see, thanks for the explanation guys.

Just to confirm, as long as there is at least a few incan lamps in the system I won't have any trouble.

Second, any $15 photocell will work, or should I try to find something better?

 

Even one should do it.

As long as it is rated for the total wattage of the lamps.

 

Great, thanks guys! 25characters

 

I've been using a photocell for years on CFL's This particular photocell does not have any indication it is acceptable with CFLs and it is rated for 1000 watts TUNG (tungsten lamps) or 1200 V.A. IND. (Inductive) The one thing that separates it from the cheaper photocells is that it is a three wire model.

 

3 wire as in a neutral, a hot (feed), and a switched hot (output) I assume?

The ones I was looking at have that. I guess the cheaper models don't use a neutral?

 

You got! You wire the photocell with the black to hot supply, the red to the hot for the lamps and all the whites together.

The cheaper photocells have only two wires and are wired between the hot supply and the hot to the lamps.


I have three 9 watt CFLs on mine but I know it works with just two. My CFLs last for at least two years, probably more. Write the date on the base of the CFL when you put them in service. Replacing the 60 watt incandescents I previously had has saved me about $5.00 a month on electricity and I get the CFLs on sale for a buck each with a utility coupon at my local "real" hardware store. It isn't even my serving utility that issues the coupon!

 

IMHO the best photo cells are TORK 3 wire cells. These are all metal with a shutter to adjust sensitivity. Most are made to mount in a 1/2 inch knockout, and will last almost forever. I have installed alot of these cells and not replaced one yet, not the cheapest, but sometimes you really do get what you pay for.

 

I've been using Intermatic photo control for about seven years on a circuit with 2 small CFLs in the range of 13 watts each. There are no other bulbs on the circuit. This control requires a neutral connection.

The first photo control, a K4141, lasted probably five years (the length of the warranty) when I noticed it was not shutting off. A post mortem indicated water damage, probably due to me installing it on the side of a surface-mount box. The K4221 has a swivel mount so it can be oriented upright to let water drain out.

One of the CFLs has been in there for about three years, running nightly. The other has been in over a year and I probably get a year or two out of that type of bulb. So I can't complain about bulb life, either.

 

For myself I use the TORK or Intermatic one of the two both been good for me for long time.

And yes the standard three wire photocell will work just about any load as listed in the photocell { yes there is a 25 amp verison but kinda pricey on that one }

Merci,Marc