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Have a waterproof box under garage eve with typical motion detector and two floods. I want to run the switched hot to a relay to turn on additional spots. So need four wires, the hot, neutral, ground, runner to the relay and a hot from the relay back to the two spots. Right now I have a 1/2" X 1" nipple from the box through the wall. If I run emt and THHN or BX, how do I clamp the wire in the box? "Dumb" question I can't find an answer to: Can I put a rigid pull on the nipple and then emt or BX on the other side? I can't find anything on going from rigid to emt. Or do I need to use a handy box as a pull? Or is there an all altogether different and smarter way to do this?

TIA

Ron

Later:

I've read that accessibility to the pull is an issue. I don't think there is any kind of a 90 or junction I can put on the nipple that doesn't have a cover that will require access. I suppose I could build a cubby with a door. It's the garage so not a huge deal and it would be just below the top plates.

I've about decided the easiest way to do this is to put an insulating bushing on the end of the nipple, run two NM into the box and use the hot in the second NM back to the spots. Staple off both in the stud bay and be done with it.

But . . . now I'm wondering if I'm putting too many connectors in the box . . . 4"X 1-1/2" round with 12 guage and lets see if I'm doing this right?? 1. Hot to sensor = 2 2. Neutral to sensor and two lights. = 4 3. Sensor to runner = 2 4. 2nd hot to two lights = 3
Arggg 11 total. Looks like I need a 4" X 1-1/2" square.

Did I get the count correct?

Again, thanks for sharing your time and skills.

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  • Sorry, WP box is on exterior of unfinished garage wall. I want a pull in case I finish wall later so there aren't connections in the wall. I found a discussion on this topic and along with laments even by electricians over no great answer, most common answer is to use NM with a Button Push-In NM Cable Connector. But no comments on how to secure THHN. Some mentioned BX and no comments from inspectors. Maybe it can't be clamped. Maybe I'm being too cautious.
    – Shiseiji
    Nov 15 '15 at 14:13
  • More thoughts . . .
    – Shiseiji
    Nov 15 '15 at 16:55
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Instead of using a 1" nipple, use one long enough to reach to the exterior of the adjacent wall. Then use a proper emt termination connector with a proper emt box. Or use a emt LB that attaches to the threaded nipple.

Either way, it sounds like your current nipple is too short.

Running MC/AC cable to a threaded nipple won't work, especially if you can't reach it.

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You said "If I run emt and THHN or BX, how do I clamp the wire in the box?" Answer is you don't. You are not required to clamp either of these after they enter the box.

To switch from rigid to EMT just use a coupling.

When you say "pull" you mean a pulling ell? Just remember anything with a removable cover is required to be accessible whether it is a box, an LB, or a pulling ell (AKA jakes)

EMT or BX connectors do not count toward the volume allowance in a box. Only internal cable clamps for NM cable.

Why are you using a relay? If your fixtures are LED or CFL the relay in the motion detector could switch multiple fixtures. Check the current or wattage capacity of the motion detector.

I think we need more information to help you. 🙁

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  • You answered all my questions. I'll look again at the motion detector wattage. I "may," can't remember, have to climb up and look, one incandescent flood that could have been the culprit that made everything cycle on/off. One 60 watt bug light at the garage door. The two floods in the fixture with the sensor are LED.
    – Shiseiji
    Nov 15 '15 at 20:14
  • Thank you ArchonOSX. You answered all my questions.I'll look again at the motion detector wattage. I "may," can't remember, have to climb up and look, one incandescent flood that could have been the culprit that made everything cycle on/off. One 60 watt bug light at the garage door. The two floods in the fixture with the sensor are LED. My confusion is counting wires and connectors. 5 connectors in the box: Hot to sensor, neutral to all, sensor out, second hot in to lights, ground. Wires: Lights have 4, sensor has three, plus 2 hot in, runner (sensor), neutral, and ground. Geez, Is that 12?
    – Shiseiji
    Nov 15 '15 at 20:29

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