# Why won't this timer work with CFLs?



## HARRY304E (Sep 15, 2010)

Dylanewilliams said:


> I just installed three of these on a service call, and the one controlling a CFL doesn't work. The reviews say other people had the same problem. Any ideas?
> 
> http://www.homedepot.com/p/Defiant-...ll-Digital-Timer-49814/203678179#.UfsnU9K1HTp



Find one that's rated for CFL's.


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## Dylanewilliams (May 17, 2013)

The client supplied them. The jobs done, but I was wondering why they dont work. I know dimmers don't work because of the way they cut off the sine wave, but this should just be acting like a switch ... right?


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## HARRY304E (Sep 15, 2010)

Dylanewilliams said:


> The client supplied them. The jobs done, but I was wondering why they dont work. I know dimmers don't work because of the way they cut off the sine wave, but this should just be acting like a switch ... right?


Yes it should.

You may need to use dimmable lamps,or LED lamps might work.


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## bkmichael65 (Mar 25, 2013)

CFL's are a non linear load


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## Dylanewilliams (May 17, 2013)

What does a non linear load mean? How does that affect the switching?


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## papaotis (Jun 8, 2013)

harry, i luv ya but i see a contradiction here in you answers. its a timer, it bshould not require anything unusual as far as what it is running. its either on or off, not dimming:no:


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## bkmichael65 (Mar 25, 2013)

It cuts off the sine wave like dimmers. I would guess that may be the problem here as well


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## FastFokker (Sep 18, 2012)

Don't think of it like a single pole switch, think of it like an electronic controller.


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## 480sparky (Sep 20, 2007)

It doesn't work because it's using the circuit to create a neutral. A very small amount of current needs to flow through the lamp so the electronics have power to operate. The CFL prevents that small amount of current flow.


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## Dylanewilliams (May 17, 2013)

480sparky said:


> It doesn't work because it's using the circuit to create a neutral. A very small amount of current needs to flow through the lamp so the electronics have power to operate. The CFL prevents that small amount of current flow.


Even though the device has a neutral connection?


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## 480sparky (Sep 20, 2007)

Dylanewilliams said:


> Even though the device has a neutral connection?


So it has three wires, plus a ground?


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## Dylanewilliams (May 17, 2013)

4 plus ground since it can be used as a 3 way switch


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## 480sparky (Sep 20, 2007)

Put in a regular old bulb and see if it works. If it does, then CFLs can't be used on that switch.


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## Dylanewilliams (May 17, 2013)

It worked on the other two lights, both 4 pin fluorescent, but the cfl has a gu24 base (you've got to love California energy codes) so I told the client to try a gu24 LED


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## 8V71 (Dec 23, 2011)

Will the CFL's not shut off? Just a wild guess here but if that is your problem it is most likely that there are electronics doing the switching instead of a mechanical relay. If they are using a triac the CFL's might not be presenting enough of a load to turn the triac off. Others members more familiar with these timers may be able to give a better answer.


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## Wirenuting (Sep 12, 2010)

8V71 said:


> Will the CFL's not shut off? Just a wild guess here but if that is your problem it is most likely that there are electronics doing the switching instead of a mechanical relay. If they are using a triac the CFL's might not be presenting enough of a load to turn the triac off. Others members more familiar with these timers may be able to give a better answer.


Same problem with LED bulbs.


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## phil20 (Apr 30, 2013)

just installed 2 with led's n they worked fine then went back to hone depot n the guys says they dont work with cfl's I taught he was nuts its just a switch


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## Ionspot (Aug 9, 2013)

8V71 said:


> Will the CFL's not shut off? Just a wild guess here but if that is your problem it is most likely that there are electronics doing the switching instead of a mechanical relay. If they are using a triac the CFL's might not be presenting enough of a load to turn the triac off. Others members more familiar with these timers may be able to give a better answer.


Good point, I would be curious to see that CFL pack...some earlier ones read "NOT for use on circuits with dimmers, timers, photocells, motion sensors or other control devices".
I suspect the triac controller for that disclaimer.


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## TQuade (Jan 22, 2010)

480sparky said:


> It doesn't work because it's using the circuit to create a neutral. A very small amount of current needs to flow through the lamp so the electronics have power to operate. The CFL prevents that small amount of current flow.






I don't think this is allowed but what if you switched the neutral instead of the feed I know it sounds shady but it would allow the light to have power for the electronic stuff inside?


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