# Lamp took out motion detector switch with it as it burned out



## HARRY304E (Sep 15, 2010)

Electric_Light said:


> I had a motion detector switch that's been working fine for years for the laundry room. Turns on with entry, out after 3 minutes. It was great.
> 
> Lamp burned out with a flash & pop on power up the other day. Nothing out of ordinary. motion detector switch is rated at 500W. It was only controlling one 100W A-19 incandescent.
> 
> ...


 What type of lamp did you install...


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## Electric_Light (Apr 6, 2010)

HARRY304E said:


> What type of lamp did you install...


100W A-19. 500W rated motion detector. Same as before.


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## guest (Feb 21, 2009)

Electric_Light said:


> When a light bulb burns out, it arcs internally and draw a large current. I'm not surprised that it happened, but the triac failed shorted on motion detector.
> 
> Should I expect the triac to fail again next time the lamp burns out?


Yes. 

Remember how great the quality of current light bulbs and motion detectors is these days.


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## MDShunk (Jan 7, 2007)

Electric_Light said:


> Should I expect the triac to fail again next time the lamp burns out?


Depends. As you have observed in your lifetime, A-lamps normally "fail ordinarily", and they sometimes "fail dramatically". Lamps have certainly been known to trip a breaker or blow a fuse when they fail, so they're certainly capable of toasting an occupancy or motion sensor.


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## Electric_Light (Apr 6, 2010)

For the pros... avoid the potentiometer controlled delay settings. The settings do not respond linearly. Stick with dip switch type. They're costly, but it saves a lot of time in setting it.


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## Dennis Alwon (May 9, 2009)

Marcs post is right on. I have seen bulbs go out and take dimmers with them. I never witnessed a bulb taking out a motion detector but I am sure it can happen. I would not expect this to be a regular occurrence.


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## Electric_Light (Apr 6, 2010)

Dennis Alwon said:


> Marcs post is right on. I have seen bulbs go out and take dimmers with them. I never witnessed a bulb taking out a motion detector but I am sure it can happen. I would not expect this to be a regular occurrence.


The lamp went out like expected. Pop, flash and out at power up.


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## Dennis Alwon (May 9, 2009)

Electric_Light said:


> The lamp went out like expected. Pop, flash and out at power up.


yep, that's is when it usually happens when power is turned on.


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## electricmanscott (Feb 11, 2010)

I smell a sales pitch for fluorescent lighting coming... :whistling2:


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## BBQ (Nov 16, 2010)

electricmanscott said:


> I smell a sales pitch for fluorescent lighting coming... :whistling2:



Or a long diatribe about how LEDs will kill our crops and rape our children.


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## Electric_Light (Apr 6, 2010)

electricmanscott said:


> I smell a sales pitch for fluorescent lighting coming... :whistling2:


I don't recommend anything other than incandescent based system for applications where light needs to come up to full brightness instantly and don't get more than 5-10 minutes per use. 

Occupancy sensors with incandescent lamps in such applications save a lot more energy than using fluorescent that will get left on from time to time. 

Occupancy sensor with fluorescent can be done, but its not necessarily a good idea. Programmed rapid start is recommended for getting good cycle life, but this adds a 1 to 1.5 second starting delay which leads to user dissatisfaction. If the usage is <30minutes a day, it's unlikely that you'll ever(in financially practical term) recover the cost by energy savings even if the saving setup used zero energy. 

Instant start will shorten lamp to life that's comparable or less than that of incandescent when it is cycled this often. 

LEDs don't realize enough savings to ever pay for itself, except in limited available power (not to exceed several watts) situation where energy cost of $50/kWh, as in the case of battery powered camping lights.


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## kbsparky (Sep 20, 2007)

Filament support wires can bend or break, causing short-circuit conditions in incandescent bulbs. This can also fry the innards of a dimmer or other electronic device such as your motion/occupancy sensor, while tripping out the breaker.


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