I am trying to add a photoelectric sensor to a 120 vac sign light at the end
of my driveway. In effect, I am splicing in the sensor into a 14/2 uf
underground cable, at the point where it comes out of the ground.
My problem is the color coding of the wires, and the very ambiguous
instructions that came with the sensor. Also, I have not wired any 120v
device for so long, I have really forgotten the color code convention, if
there is one. I say this because I tried to Google my way to an answer
before posting this query, and the results I get are not consistent. So, I
really need someone's help here with what should be a simple problem.
The 14/2 uf cable has the traditional three wires. A black and white, and
an unshielded copper wire which I know is ground. So far so good, right ?
Now for the sensor. Yes, a very simple device. Has three wires.... a
white, and black. At one time, I thought that the black wire was known as
the ac hot; the red wire was known as the "switched" ac hot. Is that
still true ? So, if this is true with respect to this sensor, then the
white wire on the sensor must be ground, right ?
Understand that I am putting the sensor in a waterproof box. So, I will
have 14/2 uf wire going into the box, through the sensor, and then 14/2 will
exit the box, and power the sign light. But , how should I connect the
On the sensor, the wire designations are Red/load , White/ neutral,
It would "seem" to me that inside the box, all of the black wires (3)
be connected together. This would constitute the ac hot line, unswitched.
But from this point, I get mixed up.... how do I connect the "switched" side
of the ac line, and how are the grounds tied together (what combination?)
I know that the two unshielded wires on the uf should be tied together, but
should I also combine the white wire from the sensor ? (On the sensor, it
is identified as the neutral).
I have two related questions.... Inside the box in which I will put the
sensor, there is a ground screw. So, instead of putting all grounds
together with a wire nut, should they instead go to this ground screw ?
Last question... if I wire a 14/2 to a grounded ac plug ( 3 prong plug)
how do you decide which side of the plug the black wire goes to and the
white wire goes to ?? Although the 14/2 carries its own ground wire,
isn't there still a safety point to have the current carrying wires
connected in a standardized way ??
I know these are all very green questions, but of course I want to do
right, and I want to do it myself.
Can someone here help me with this please ??
Thank you very much !!