Motion switch - incandescent vs. CFL

[IGot2P]

I just installed a motion detection switch in one room which is lighted by 4 CFL's in a fan. The CFL,s come on fine but when the motion switch shuts them off they just flicker. Of course if I put 4 incandescent bulbs in the unit all is fine. For the heck of it I put in 3 CFL's and 1 incandescent bulb and to my surprise they ALL work!

Is there any reason that I can't leave it as above (3 CFL's & 1 incandescent)? In this manner I can save some electricity and still have my motion switch work.

If necessary can I purchase CFL's that will work with my motion switch or can I purchase a different motion switch that will work with my current CFL's?

Comments would be appreciated.

Don

[trader4]

People have done this with a variety of electrical controls, and gotten it to work. But the other question is, what is the motion detector rated for use with? It's probably rated for use with incandescent only. In that case, without knowing what motion detector or how it's designed, no one can say what the long term effects will be on the motion sensor. On the other hand if it just says it's rated for use with loads that have to be a min of X watts and you get it to work by using a regular bulb to increase the wattage, then I'd say you're OK.

I doubt that.

or can I purchase a different motion switch that will work with my

I'm sure there are motion switches rated for use on CFL, LED, etc.

[Dean Hoffman]

Cut a bunch due to AIOE quotation limit.

Would some sort of suppressor burn off the excess current? Maybe a trip to Radio Shack would solve the problem. He could wire it to the hot and neutral in the junction box for the light fixture.

[BenignBodger]

The cheap motion switches you find in the local Borg are two-wire devices which depend on current through the load to provide working power for the control circuit. With incandescent lights this is no problem since a few mA drawn through the filament wastes almost no power and emits no light. CFLs, on the other hand don't really conduct properly until there is considerable voltage applied. I ran into this just as you did except mine was in a laundry room. I finally wound up using one small (40W?) incandescent lamp and a fairly high output CFL in the two-socket fixture. It worked fine like that for at least eight years. There are better sorts of motion detectors out there but they depend on there being both a hot and neutral inside the switch box and this is not generally what you see in home wiring. You have to judge whether it is worthwhile re-wiring to make the better (more expensive) motion switches work. It might be interesting (but expensive) to test LED lights in place of CFLs and when the prices come down a bit I might give them a try.

[DerbyDad03]

Incandescent bulbs are often added to X10 controlled circuits to make them work with fluorescents. Even something as small as one of those Christmas candles will work.

[IGot2P]

I just uploaded the specs and the installation diagram to one of my domains. To look at them just point your browser to

Don

[IGot2P]

Actually, another subject but your reply reminded me that I have a whole box of X10 stuff somewhere that I never did use. Someday I will have to get that out and put it on ebay.

Don

[clare]

The switches that require a neutral usually work with CFLs. The ones that do not need a neutral generally do NOT. No problem using one straight resistance load (incandescent bulb) - even a 3 watt will do the job.

[gfretwell]

As everyone else has said, just keep an incandescent in the circuit. I have a bunch of these around my house and even something like a segment or 2 of rope light will work. It really all depends on what you are trying to do. OTOH a regular motion head like the Heath/Zenith works fine with a CFL but that does require a neutral.

As an aside, the NEC now requires (2011) a neutral at every switching location, just because of this problem.

[IGot2P]

You said that it requires a neutral. Is that different than the uninsulated ground wire that I have in the switch box?

Don

[gfretwell]

Yes. The ground wire is for safety and should never be used as a current carrying conductor. If there was an up steam fault, the case of any 3 prong plug equipment would be hot.

There used to be an exception to the listing standard that allowed

0.0005a of current on that wire but it was removed. That is still less than the electronics in an occupancy sensor.

[trader4]

The spec says it will work with 30W min fluorescent. It will also even run a small motor. So, your strategy of using one incandescent to up the current, and 3 or whatever CFL is perfectly fine.

[trader4]

If you mean a surge suppressor, no, they don't burn current. They look like an open circuit until the clamping voltage is exceeded.

[Art Todesco]

I have one of those motion detectors in the bathroom, connected to the nightlight feature in the heater/fan/light/nightlight. A standard nightlight bulb, flashed and blinked when off. I went to a 15 watt bulb and flashing stopped. But, if you look at is when it's off, the filament is glowing just a bit. Not a problem for my application. It's really nice to go into the bathroom at night, an have the nightlight turn on.

[Art Todesco]

Let us know when you put the stuff up for sale.

[Art Todesco]

See my answer in this tread above. But in my case, even a nightlight bulb flashed and blinked when the motion switch was off. Nightlight bulbs can be 4, 5 or even 7 watts. And, totally off the topic of this tread, I recently found, at Lowe's, of all places, 10 watt nightlight bulbs, but they are the pear shaped one. I think they used be, or still are called indicator lamps.

[clare]

Technically and legally, yes. Functionally, no.

Have I used it? yes Would I recommend it,? No Is it to code? HECK NO!!!!

[gregz]

You would think new switches would work on the new agenda. Relays work well with cfls. Mechanical relay.

Greg

[clare]

They only work with a neutral because you need to get current flowing through the coil to turn on the light. Not enough current through a cold CFL to reliably turn on the relay.