# Motion sensor causing lights to flicker



## Zaunerstollen (Nov 29, 2010)

I'm having a weird problem with my newly installed garage lights on a motion sensor switch. I have a new, dedicated circuit that was installed this morning. On this circuit I have an always live outlet for the garage door and four porcelain ceiling lamp holders on a motion sensor switch. Each of the lamp holders has a 27W CFL light bulb on it. The lights flicker when the switch is set to AUTO and stop flickering when the switch is set to ON. I also noticed the motion sensor indicator on the switch flickers too on auto. Also the speakers on my computer (which are inside on the other side of the house) hum when the garage lights come on. The computer is on a different circuit altogether. I'm returning the motion sensor tomorrow hoping it is only faulty. You guys have any thoughts or ideas on this? Thanks in advance.


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## DangerMouse (Jul 17, 2008)

Does the sensor box say anything about using CFL bulbs? That might be the problem. 
Buzzing speakers could be a grounding problem.
hmmmm....

DM


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## Zaunerstollen (Nov 29, 2010)

Thanks for the reply DM. The pamphlet sent with the sensor says nothing about CFL lights. That is a good point though and I will ask the guys as the hardware store about it. As far as a grounding problem, the last lamp holder at the end of the series is not grounded. I did not have a screw to attach it to so I capped it off. I have two separate bus bars in my circuit breaker box and I did make sure the ground for this circuit was put on the correct side. If the unattached ground on the last lamp holder is the problem and I do indeed have a grounding issue, can that really cause an issue on a separate circuit? The TV and stereo, which are relatively closer to the garage than the computer did not hum.

On a slightly side note, if I can attach the neutral and ground on the same bus bar in a box with only one, should I attach the ground to the second neutral screw on the last lamp holder? I didn't do it and even think that that is wrong. But then again, I'm not an expert.


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## AllanJ (Nov 24, 2007)

The neutral may not be connected to ground anywhere except in the panel where the first main disconnect switch (may be a breaker) is located.

Or did the instructions mention any kind of light as preferred or required? Tungsten means incandescent.


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## Zaunerstollen (Nov 29, 2010)

Thanks Allan. I figured that about the neutral/ground wires. Just wanted to check. I assume I should just leave the last ground wire as is and capped, right?

The specifications for the sensor state:
"Max 500W Incandescent/Halogen"
"Max 500VA Fluorescent (2 tubes min)"
"Must use min 30W load"

The pamphlet that came with the sensor did not specifically mention "CFL" bulbs but they do talk about fluorescent tubes. I'm assuming they are close enough that I can use them. Do you think the possible grounding issue could be causing the flickering?


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## frenchelectrican (Apr 12, 2006)

Can you expand little more on the motion switch do this motion sensor did use the netural conductor or not if not then that is the issue with electronic ballast.

And the brand name of motion sensor as well.

Before I can rule this out try unscrew one CFL and put in 60 to 100 watt incandescent bulb to see if that clear up the flicking issue if that did stop the flickering then you will need to get a motion switch with real netural connection that will slove the issue pretty much what you have there.

Merci.
Marc


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## Zaunerstollen (Nov 29, 2010)

Thanks Marc. The name of the company is "Tough and Glow." I went on their website and found a similar motion sensor. The online specs state: 

"No Neutral Connection Required"
"Works with CFL, Fluorescents, fans, and motors"

My motion sensor does not have neutral hook ups. I has a black wire (Line), a red wire (Load), and a green wire (Ground). I'll have to reattach the motion sensor to try the incandescent lights. I will give it a try.

Merci.


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## frenchelectrican (Apr 12, 2006)

Just try one incandescent bulb and leave the rest { CFL } alone if that did the trick I will give you a trick how to slove it.

Merci.
Marc


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## Zaunerstollen (Nov 29, 2010)

I reinstalled the motion sensor and turned the circuit back on. The lights still flickered. I then changed the last CFL bulb with a 60W incandescent bulb and the flickering stopped as well as no more humming on the computer speakers. Upside, it worked. Downside, I have no idea what just happened! How did that "fix" it? and What do I need to do so I can put the CFL bulb back?


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## DangerMouse (Jul 17, 2008)

Zaunerstollen said:


> "Must use min 30W load"


I believe this is the key..... the 60w incandescent has a higher load. 
Perhaps if you try a higher wattage CFL on one and see if that works?

Of course, I could be wrong, as usual, but when Marc comes back he may have the correct answer.

DM


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## Zaunerstollen (Nov 29, 2010)

When I saw "min 30W load" for the sensor, I assumed that was 30W total. Do you think they meant per bulb? or Does at least one bulb have to be over 30W? There is no literature I could find in the pamphlet on the company's website.


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## DangerMouse (Jul 17, 2008)

Zaunerstollen said:


> Does at least one bulb have to be over 30W?


That's what I'm thinking. Do you have a higher watt CFL to test with? One that's over 30 actual watts? (equivalent to 150w/200w incandescent, maybe higher.... don't quote me)

DM


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## DangerMouse (Jul 17, 2008)

It may be too that the incandescent bulb has a different architecture that allows it to work.
Remember, CFL's all have little ballasts built-in, right?

DM


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## Zaunerstollen (Nov 29, 2010)

I do not know as a fact, but that sounds right. It would have to have a similar inner workings as a tube. Also, the highest CFL I have right now is a 26W.


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## DangerMouse (Jul 17, 2008)

Marc will likely explain it better, but I think we're onto the culprit here.
Does the 60w do the same trick in any socket, or just the last? Or haven't you tried it in others?

DM


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## Zaunerstollen (Nov 29, 2010)

If I put the incandescent bulb in any of the receptacles I have the same result, no flickering and no humming on the computer speakers. When I have only three bulbs in any combination (1, 2, 3 or 2, 3, 4, etc.) I still have no flickering but I do have humming on the computer speakers. I now have the incandescent bulb on the first receptacle.

I called the manufacturer and the technician said the 30W load is the minimum total, not individual bulbs. Each of my bulbs is 23W. He also said if I wire the receptacles in series that should take care of the problem. I thought I did that. He stated that a parallel scheme will get less power to the sensor.

I have the wire from the circuit breaker box going into a junction box where it splits to the dedicated garage door outlet and the motion sensor, nothing more. The wire then comes out of the motion sensor to the first receptacle. I have the wires coming in and going out wired together with a pigtail with connects to the receptacle. This continues to receptacles 2 and 3, with receptacle 4 having only one 12-2 wire entering and hooked up to the receptacle. I do not have a connection in any of the receptacles for a ground so the ground wires for 1, 2, and 3 are wired together and 4 is just capped off. The ground wires for the line and load at the motion sensor are connected to the ground of the sensor.

Any new thoughts?


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## DangerMouse (Jul 17, 2008)

Leave one incandescent bulb in and call it a day? LOL
I'm betting it's still the ballasts on the CFLs.

DM


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## frenchelectrican (Apr 12, 2006)

For the light sockets do NOT wire them in series they are connected in parallel that mean from light socket to light socket is Black to Black and White to White that it nothing else with the connection confreation if you do diffrent the light will be dim or CFL will flicker or stay dim one of the two depending on the ballast design.

Now for the two wire motion sensor { sans netural verison } it do need a incentscent bulb on to act like a shunt to keep the motion sensor electronic control working { myself I never use the 2 wire motion sensor much as possible always get 3 or 4 wire motion sensor depending on conferation like single pole or three way switch set up }

And with electronic ballast they will flicker due the voltage surge it will bounce up and down to get the motion sensor electronic control to work.

All the motion sensor I install are with netural due obovous reason of CFL electronic ballast or LED one of the two will drive some motion sensors with out netural batty and I have got this kind of service call both USA and France side { Our French code we are required have netural at switch point now it was in effect for 2 years allready }

If you really want to keep all CFL on that switch then you will have to exchange that and get one with netural only if you have legit netural in your switch box the switch loops are out of the window on this one.

If have more question just holler one of us will help ya.

That situation will apply to lighted switch handles when the lights are off it the excat the same situation.

Merci,
Marc


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## Zaunerstollen (Nov 29, 2010)

Merci, merci Marc!! I very much appreciate your help and advice. Have a wonderful Christmas!


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## frenchelectrican (Apr 12, 2006)

Not a problem at all and have a nice Noël to you.


Merci,
Marc


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## emolatur (Nov 8, 2010)

MRRRH!

"No neutral connection required"!

THAT is the problem.

The problem is the standby current required by the electronics in the sensor.

The first thing a CFL does with AC is chop it up into DC and charge a capacitor with it.

Pull a small current through it long enough the cap will eventually charge up enough to let the electronics work, and the lamp will light, draining the cap rather quickly. The process will repeat. The light will "flicker" or even "flash". The problem is that CFLs are not even remotely resistive loads.

Add an incandescent bulb, which IS a resistive load. Further, a cold filament has a very low resistance. Now your standby current doesn't have to go through rectifiers and won't light your CFLs.

THAT is the difference.

The entire problem would be solved with a motion sensor that has its own neutral connection.


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## bobelectric (Mar 3, 2007)

Reminds me of the time I got hit changing a ceiling fixture with the switch off.It was a lighted switch.


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## frenchelectrican (Apr 12, 2006)

bobelectric said:


> Reminds me of the time I got hit changing a ceiling fixture with the switch off.It was a lighted switch.


Tell me about it I got zonked few time when I am not looking at lighted switch handle even the neon bulb pretty much burnt out and still get ya 

That why I have to double check the switch handle set up and what conferation and use the NCV tester and wiggy tester to verify it.

Merci,
Marc


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## VersaBar (Nov 30, 2010)

bobelectric said:


> Reminds me of the time I got hit changing a ceiling fixture with the switch off.It was a lighted switch.


Fan remote modules might shut off the power enough to stop the fan from turning, but there is still enough juice there to wack you good, ask me how I know


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## frenchelectrican (Apr 12, 2006)

VersaBar said:


> Fan remote modules might shut off the power enough to stop the fan from turning, but there is still enough juice there to wack you good, ask me how I know


Try that with T&K set up that will useally get ya espcally when someone did not pay attetion between active and netural conductors.

I have dealt with this mess for a while in European side not much diffrence between the two beside the voltage.

Merci.
Marc


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## Zaunerstollen (Nov 29, 2010)

I think I may have found my item. I found an item labeled an "occupancy sensor" at a competitor's store. This item states: 
Requires a neutral (white) wire connection

I'm going to pick it up tonight and install it tomorrow morning. I'll let you guys know how it works. I really appreciate all of you helping me figure this out.


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## homerb (May 7, 2010)

frenchelectrican said:


> Just try one incandescent bulb and leave the rest { CFL } alone if that did the trick I will give you a trick how to slove it.
> 
> Merci.
> Marc


Good point. I had the same issue when I tried to use CFL lights with a decora motion sensor switch. I replaced one with incandescent and left the rest CFL and it worked fine. 

Homer


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## Zaunerstollen (Nov 29, 2010)

I think I may finally have and answer to this. I talked to a technician from the company that manufactured the sensor. He said that I wired the system in parallel initially and presently. He said series would fix the problem. This is how he explained it should be wired:

12-2 from the motion sensor enters the box for light number one. Black from the line attaches to one connector and black the load connects to the other. The neutrals are connected together and not to the light. This continues through light numbers two and three. At light four, the 12-2 inters the box and each wire is attached to the respective connector on the light. That he says is a true series and will give enough of a draw to exceed the minimum amount for the motion sensor, light will no longer flicker, and problem solved. Sounds correct to me, how about you guys?


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## dmxtothemax (Oct 26, 2010)

If the motion sensor uses a triac to control the load,
then maybe the output is not clean,
chopped in some way,
possibbly a faulty triac.
Or the circuit doesnt like the inductive load of the CFLs.
Try a new one.



Zaunerstollen said:


> I'm having a weird problem with my newly installed garage lights on a motion sensor switch. I have a new, dedicated circuit that was installed this morning. On this circuit I have an always live outlet for the garage door and four porcelain ceiling lamp holders on a motion sensor switch. Each of the lamp holders has a 27W CFL light bulb on it. The lights flicker when the switch is set to AUTO and stop flickering when the switch is set to ON. I also noticed the motion sensor indicator on the switch flickers too on auto. Also the speakers on my computer (which are inside on the other side of the house) hum when the garage lights come on. The computer is on a different circuit altogether. I'm returning the motion sensor tomorrow hoping it is only faulty. You guys have any thoughts or ideas on this? Thanks in advance.


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## frenchelectrican (Apr 12, 2006)

Zaunerstollen said:


> I think I may finally have and answer to this. I talked to a technician from the company that manufactured the sensor. He said that I wired the system in parallel initially and presently. He said series would fix the problem. This is how he explained it should be wired:
> 
> 12-2 from the motion sensor enters the box for light number one. Black from the line attaches to one connector and black the load connects to the other. The neutrals are connected together and not to the light. This continues through light numbers two and three. At light four, the 12-2 inters the box and each wire is attached to the respective connector on the light. That he says is a true series and will give enough of a draw to exceed the minimum amount for the motion sensor, light will no longer flicker, and problem solved. Sounds correct to me, how about you guys?


Do not hook them up in SERIES otherwise you will have the light very dim or not functing at all.

All the light sockets are wired parllel no question asked.

I do not know why that tech guy try to give you a silly advise to you it will NOT work with both CFL and inscentsent bulbs at all { I know the insencents may lit up but super dim so not worth it on this part }

Let me post the photo










This will give you a clear idea why keep it parallel.

Merci.
Marc


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## rtinsley (Nov 27, 2011)

*CFL's the problem*

Had the exact same problem. Lights worked great when set to "on" but on Auto flickered. Replaced one of the 6 CFL's on the circuit with a 40w bulb and everything worked fine.


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