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Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ

motion detector security light question

Click for full size
I asked this over in the home improvement forum and didn't get a definitive answer.

would it be OK to install a switch between the hot in and switched hot out on a motion detector to keep the lights on at all times? I know I can bypass the lights by turning the breaker off then back on, but that is only for one night until the built in photocell resets it in the morning.

here's a (pretty crappy) diagram of what I was thinking. would this hurt the sensor in any way?

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:2
I think that should be OK since it is just parallel to the photo-sensor which also acts like a switch.


Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ
reply to Sc0tt
that's what I was thinking. just wanted some assurance

even if I do fry it, it is after all only a $20 part LOL.

thank you for your reply!!


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET

1 recommendation

reply to Sc0tt
If you want to play it safe, you could use a toggle switch (SPDT):
L1 connects to black(hot) from the junction box and the black control wire from the motion detector (input).
L2 connects to the red control wire from the motion detector (output).
C (common) connects to the black wires from the 2 light.
In position 1 the lights are permanently on. In position 2 the lights are motion controlled.

If you want to get really fancy you can get a toggle switch with a center off position which allows to turn the light off completely.
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lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:2
miniature rocker switch / center off $1.32

»www.parts-express.com/pe/showdet ··· =060-674


Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ
reply to Sc0tt
I actually have a few SPDT toggles at work. that sounds like a better idea---maybe I had too many beers due to the holiday weekend and didn't think it through enough LOL.

i'll be grabbing one Tuesday and hooking it up that evening. thanks for the help and ideas!!


54067323

join:2012-09-25
Tuscaloosa, AL
said by Sc0tt:

I actually have a few SPDT toggles at work. that sounds like a better idea---maybe I had too many beers due to the holiday weekend and didn't think it through enough LOL.

If this install is outside you will want to use a properly rated switch in a rain tight housing with a proper rain tight cover.

The last thing you need to do is create an electrical hazard with a wet switch.


tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
kudos:9
Reviews:
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reply to Sc0tt
Click for full size
3-way switch override
said by Sc0tt:

I actually have a few SPDT toggles at work. that sounds like a better idea.

Using a 3-way switch is probably overkill but can't hurt.

That is how I set up our bathroom light/fan timer using a 3-way switch to allow fan to be run continuously.

Here is a schematic if you want a pretty picture.

/tom


Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ
reply to 54067323
said by 54067323:

said by Sc0tt:

I actually have a few SPDT toggles at work. that sounds like a better idea---maybe I had too many beers due to the holiday weekend and didn't think it through enough LOL.

If this install is outside you will want to use a properly rated switch in a rain tight housing with a proper rain tight cover.

The last thing you need to do is create an electrical hazard with a wet switch.

all our stuff is for outdoor use.

the switches are 1/2" hole mount, direct exposure rated. I even have the rubber covers for them


54067323

join:2012-09-25
Tuscaloosa, AL
said by Sc0tt:

the switches are 1/2" hole mount, direct exposure rated. I even have the rubber covers for them

And "listed" for that application?


Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ
they're listed as (I believe) service disconnect switches for incandescent/fluorescent/neon signs. rated for 120-250v either 15 or 20 amp.

i'm only running 3 60 watt lightbulbs on it, so 1.5 amps. they are usually controlling 2 to 3 15000v/30ma neon transformers or a few ballasts.

...........which reminds me. if anyone needs a neon transformer for any projects, just PM me. I have a $h!tload of used ones that are still good, up to 15000v 60ma.
FTF only---they're WAY too heavy to ship.


mackey
Premium
join:2007-08-20
kudos:14
reply to Sc0tt
And just because no one's mentioned it in this thread, a "3-way" switch is just a SPDT switch.

/M


Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ
the ones I have are only on/on. so I guess it's a 2 position in my case I have no need for an "off" position anyway. it's either on by the motion sensor, or the photocell that feeds the circuit.


Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ
reply to Sc0tt
Click for full size
here's a diagram of how I have the switch wired. there is a photocell out to the left of what I sketched which will control the light when the bypass is activated for special occasions (Halloween, Xmas, ETC) and possibly all winter. I tested it tonight, and it seems to work perfectly with no fried sensor

thanks all for your input and help!!


tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
kudos:9
Reviews:
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·G4 Communications
Great when a plan comes together.

One thing I noticed is you are switching power to the motion sensor. That's fine and saves the watt or so the sensor is using. However: the sensors I've had turn on the output for a bit when first powered up. If that behavior is acceptable great, if not leave the sensor powered all the time and switch the output for manual control.

/tom


Sc0tt
Kneedragger
Premium
join:2000-11-13
Stockholm, NJ
reply to Sc0tt
will the way I have it hurt the sensor at all after time? if powering the sensor all the time is better I can just jump the two wires together.

this one does power the lights for a few seconds on initial power up, but if it won't kill the sensor I may just leave it as it doesn't really bother me.


tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
kudos:9

1 recommendation

The way you have is wired is fine, after all the sensor is wired in after a photocell.

I was just commenting on a potential usage issue.

/tom


mackey
Premium
join:2007-08-20
kudos:14

1 recommendation

reply to Sc0tt
said by Sc0tt:

will the way I have it hurt the sensor at all after time?

I'd be very worried about backfeeding the SSR (or whatever they're using) like that, especially with no incoming power.

This is what I'd recommend:



/M


tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
kudos:9
Reviews:
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·G4 Communications
said by mackey:

I'd be very worried about backfeeding the SSR (or whatever they're using) like that, especially with no incoming power

The Triac or back to back SCRs are not being driven since the input is disconnected. The circuit as Sc0tt See Profile implemented it is not going to cause a problem.

/tom


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
reply to mackey
That matches what I had recommended.

Since this particular motion sensor has a neutral connection (many don't) a current can flow through the sensor regardless whether line voltage is applied to the input or to the output (backfeed).

While I don't expect necessarily any harm to come from it, I would not backfeed the motion sensor since it is not a normal operating condition for which it would be designed.
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