I purchased PFA121 junction boxes for an install. I wanted to drop down from under the roof eve with 1/2" EMT to allow a cable pull from the attic. The PFA121 junction box has 3/4" threaded side holes, rather than 1/2" found on other junction boxes. This resulted in a little more work to figure out how to attach the 1/2" EMT via a compression fitting.
Here is the option I used:
1.)Purchased "raintight" 1/2" EMT compression fittings, 3/4" to 1/2" bushings and 3/4" locknuts. All should be found in the accessories area of the store where you purchased the 1/2" EMT conduit. (Probably could skip the locknut if you are careful later when tightening the compression fitting not to break the added silicone).
2.)Thread 1/2" EMT compression fitting into the 3/4" bushing and tighten. The compression fitting has a black rubber gasket. Tighten but do not over tighten.
3.)Place light amount of silicone on the 3/4" bushing threads and back of locknut if you use one.
4.)Thread bushing through PFA121 junction box. (Add locknut on inside if you use one)
5.)Tighten bushing/compression fitting to box to seat the black rubber gasket to the top of the PFA121 junction box. Silicone on the threads will work as a thread seal/locker and will also place a small bead around the opening on the inside and outside.
6.)Allow time to set/dry then attach to rigid conduit.
I did try using a 1/2" compression fitting directly in the 3/4" side hole on the PFA121 junction box, with a locknut. Too much tightening began to pull it through the hole and warp the gasket. I was concerned about potential for water seepage.
Here is the option I used:
1.)Purchased "raintight" 1/2" EMT compression fittings, 3/4" to 1/2" bushings and 3/4" locknuts. All should be found in the accessories area of the store where you purchased the 1/2" EMT conduit. (Probably could skip the locknut if you are careful later when tightening the compression fitting not to break the added silicone).
2.)Thread 1/2" EMT compression fitting into the 3/4" bushing and tighten. The compression fitting has a black rubber gasket. Tighten but do not over tighten.
3.)Place light amount of silicone on the 3/4" bushing threads and back of locknut if you use one.
4.)Thread bushing through PFA121 junction box. (Add locknut on inside if you use one)
5.)Tighten bushing/compression fitting to box to seat the black rubber gasket to the top of the PFA121 junction box. Silicone on the threads will work as a thread seal/locker and will also place a small bead around the opening on the inside and outside.
6.)Allow time to set/dry then attach to rigid conduit.
I did try using a 1/2" compression fitting directly in the 3/4" side hole on the PFA121 junction box, with a locknut. Too much tightening began to pull it through the hole and warp the gasket. I was concerned about potential for water seepage.
