Security Light

[Malcom "Mal" Reynolds]

My friend has a 100 watt mercury vapor security light on her garage that for the most part won't turn off. she's replaced the bulb, it needed it anyway, but the guy doing her handyman stuff says the sensor has to face north. the wall the light is mounted on faces east, north faces a 12 to 18 inch roof overhang. seems like it would make more sense to face east or even south east, but she isn't sure if the sensor is able to be rotated and since she has a new one to put in with what looks like a weird electrical outlet three prong plug, I doubt that it can be rotated. Any recommended fixes?

[Tony Hwang]

Hi, Does sensor have a shade like camera shade on it and/or is there an adjustment for setting the sensor sensitivity. My El Cheapo 9.99 security flood light has two adjustment. sensitivity, turn off delay, If there is no adjustment try blocking the sensor opening partially with piece of black tape like a shutter. May have to fiddle with it few times.

[trader4]

Did it ever work? If so, then it would sound like it's the photoelectric sensor that's kaput. I don't buy the idea that it has to face north. If anything that would make the light go off easier, because more light would hit it.

[Tomsic]

Installation recommendations for dusk/dawn controls are that they face north so that direct sunlight doesn't fall on the photocell. That gives the best on and off times -- not too dark, not too light. The sensor with the strange plug is a standard street light type. It locks into place and then either the socket or the sensor head is designed to be rotated.

In your friend's situation, aim the sensor opening toward the north and then rotate it until it "sees" a bit of sky.

Mercury vapor ballasts and lamps are now obsolete and will no longer be sold once existing stocks are gone, but they last a long time -- typically 24,000 or more hours. Dusk-to-dawn operation is about 4,000 hours/year.

Tomsic

[John Grabowski]

*Put the new sensor in and see what happens. It sounds like it is a standard twist lock type. Plug it in and rotate it until it locks in place. Sometimes there is a shade that can be adjusted to the proper direction.

[HeyBub]

Better?: "... go ON easier, because LESS light would hit it."

[Ed Pawlowski]

Maybe he is in New Zealand

[George]

North facing is the recommended alignment for PE sensors in that application because it gives the best result.

[trader4]

It may give the best result but it has nothing to do with the light not turning off, which is the issue at hand. Which direction receives the least light? You have some half-assed handyman attributing the fact that it won't turn off to the fact that it's facing north. I say BS.

[Smitty Two]

Could be a cruddy switch. G.F. has a motion-sensing security light in the carport that was staying on. There were a couple of slide switches and a potentiometer on it. The pot adjusts sensitivity, and the slide switches adjust ON time and override the motion-sensing feature so it can be manually operated. At any rate, I "fixed" it by exercising the switches and pot.

Your friend's is apparently a dusk-to-dawn (light sensing) rather than motion-sensing, but either way you'll likely find one or more switches on the sensor that haven't been touched in years. Exercise them, spray 'em with WD-40 or contact cleaner, or replace. Of course, the sensor window could be getting cloudy, or the sensor could be failing for some other reason, but the switch manipulation is a good first effort.

[hrhofmann]

Excellent suggestion!!

[Malcom "Mal" Reynolds]

granted that the handyman is probably out of his depth with this particular issue

[Malcom "Mal" Reynolds]

as of this moment, it appears that putting a replacement sensor has solved the problem. I'm a little leery of saying it's cured because she's got another set of security lights that get "cured" and work for a bit and then decide they won't.

But thanks to everyone for the help. I didn't actually see the installation but did see the replacement sensor and it didn't have a "shad" or adjustment switches.

[Norm A. Brams]

Yah, I feel your pain. It has been my experience too that the consumer-grade motion sensors and photocells purchased from McLowesDepot are garbage. Seems they last a few months and then die. I gave up on them but maybe a sensor from an electrical supply house might last longer???

[Malcom "Mal" Reynolds]

happy to report that after 24 hours the light is functioning as it should

[bud--]

If the light stays on the only likely culprit is the sensor, which you replaced.

They should face north because direct sunlight on the sensor tends to kill it. It won't last as long depending on the sunlight exposure.

I don't remember how it works, but the top can be rotated relative to the base.

I hope the installer figured out the plug is twist lock and should be inserted and twisted clockwise.

[Twayne]

have to agree; the sensor is the major component and as long as the bulb contacts the internal contacts, it's positioned where light isn't shaded, sensor is properly wired, then it should work. In the 30 years here we've only ever replaced the sensor one time and had to reset the screws to hold the reflective shade in place. Beng rural here, there are thousands of them around and they all have the same records of longevity, best II can tell. A couple years ago we switched to a sodium vapor bulb/sensor and now we only put iit on for guests arriving or during a storm, especially snow storms.

[Twayne]

True: but any orientation that allows it to "see" liight/dark without interruption is acceptable. North (magnetic north) is simply used to make sure east & west times correspond properly wthout a slight difference in light receieved otherwise.