wrote:

My wife bought a "security light" at Costco, to be installed above the
garage door, below the eve of the roof. It's a basic model, with two
bulbs, probably no more than $50. The unit looks identical to what is
shown at the following URL (no ads or popups, or dancing monkeys, so
feel free to click.)

http://www.cornerhardware.com/howto/ht015.html

We did not previously have an exterior light above the garage door, so
there was no electrical outlet. Inside the garage, there was an
available outlet, about 5 feet away from the door. So, I bought a cheap
extension cord, plugged the pronged end in the outlet. I put the
extension cord through the hole, cut and threw away the end of the
cord, and attached the the hot and neutral wires to the corresponding
wires on the security light. It works, but I have two questions /
concerns:

Q1. I was able to run only 2 wires from the outlet, so there is no
grounding wire running from outlet to the "circular plate covering the
hole in the wall", as shown in the picture at the URL listed above.

Is this a complete no-no? As I asking for trouble?


You won't have to look for it, it will find you my friend..


Or is it OK? I have
some small appliances (desk fan, table lamp, etc.) that use cords with
only two wire -- no grounding wire.

Also, the extension cord from outlet to the security light is only 5
feet, well insulated, and the security light is mounted well above the
ground. There are no metal parts near it (garage door is an ancient, 30
year old, single panel, wood door).


You have done something which would not pass code inspection and which
might just let an accident happen which will incrementally raise the
cost of homeowners' insurance for all the rest of us. G

If you have an outlet 5 feet from the light location, and it has a
ground running to it, it shouldn't take much work to remove the outlet
and mount a metal surface mount box on top of the existing outlet box
and then run metal conduit with black, white and green wires in it over
to where your security light is. You could remount the outlet in the
surface mounted box.

And, install a metal box behind the light too if there isn't one there
already.


Q2. When security light is activated, it suffers from flickering IF the
garage door is fully open. If the garage door is closed at least 20% or
so, i.e., the door panel is angled at least 20 to 30 degrees, the
flickering stops (0 degree means fully open; 90 degrees mans fully
closed)

This is again due to reflection from the garage door (painted white). I
treat this flickering as a feature (reminding us to close the garage
door), but my father thinks of this as a bug. Any suggestions to avoid
flickering? (Sort of upgrading garage door to a new, sectional kind).

The URL you gave shows a MOTION detector light, yet you seem to be
talking about a daylight sensing light. Are you sure you know what your
wife bought?

If it IS a daylight sensing light, you might be able to eliminate the
flickering by repositioning the direction the sensor is looking, or by
fabricating and tacking on a little shade to keep it from "seeing" the
garage door as much.

HTH,

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."