elec64
New member
- Location
- Toronto, Canada
I am an electrical engineer but not a certified electrician. I know enough to ask this question so that I don't end up in a code violation bind. I've spent a good week reading forums to look for a clear answer but I don't believe I have found what I am looking for.
The setup: I have am mounting a new outdoor electrical outlet 30" above the exit point from the house. I am using THHN-14 and not stripping ROMEX cable for the cable run. The PVC 40 pipe extends 1 to 2" into the basement headers. What I wish to do is bring those 3 cables into the house and a foot (or less) over to a cut-off switch.
The $64000 question: must I run the PVC conduit all the way from the entry point into the house and over the electrical box of the cut-off switch? I believe this is defined as a "closed conduit circuit", by code, and hence the answer may be yes.
The reason I would prefer not to do this is because:
(1) It will be very tricky to create a series of connected pipes to go from the entry point to the cut-off switch box in the basement ceiling,
(2) Thermal expansion of the PVC (if any) is a hindrance for those short length of piping in the basement (I won't easily be able to provide for thermal expansion on the short pipe),
(3) My serious concern is that water will most likely enter that pipe in the future as the exterior PVC connections crack (due to thermal expansion in the -40C to +40C range of temperature). That water will drain directly into the electrical box.
What I would personally like to do is have PVC conduit coming into the house for 2", and a short length of pipe going into the electrical box, but allow for 4" to 6" of exposed THHN wires between them. That would resolve all (3) issues above. I would wrap the exposed wires in electrical tape. These wires may be exposed but they are hidden above ceiling tiles. Would this be a code violation?
If I did not know any better than I would simply had used ROMEX cable to solve this issue -- Sheathed from the basement cut-off switch box and 1" into the PVC tubing, then stripped all the way to the outdoor electrical socket. I know that some people say that this is okay but I have gone the THHN cable route due to the pipe being exposed to the sun all day.
Thanks for the consideration of this issue and I do appreciate any follow up comments.
The setup: I have am mounting a new outdoor electrical outlet 30" above the exit point from the house. I am using THHN-14 and not stripping ROMEX cable for the cable run. The PVC 40 pipe extends 1 to 2" into the basement headers. What I wish to do is bring those 3 cables into the house and a foot (or less) over to a cut-off switch.
The $64000 question: must I run the PVC conduit all the way from the entry point into the house and over the electrical box of the cut-off switch? I believe this is defined as a "closed conduit circuit", by code, and hence the answer may be yes.
The reason I would prefer not to do this is because:
(1) It will be very tricky to create a series of connected pipes to go from the entry point to the cut-off switch box in the basement ceiling,
(2) Thermal expansion of the PVC (if any) is a hindrance for those short length of piping in the basement (I won't easily be able to provide for thermal expansion on the short pipe),
(3) My serious concern is that water will most likely enter that pipe in the future as the exterior PVC connections crack (due to thermal expansion in the -40C to +40C range of temperature). That water will drain directly into the electrical box.
What I would personally like to do is have PVC conduit coming into the house for 2", and a short length of pipe going into the electrical box, but allow for 4" to 6" of exposed THHN wires between them. That would resolve all (3) issues above. I would wrap the exposed wires in electrical tape. These wires may be exposed but they are hidden above ceiling tiles. Would this be a code violation?
If I did not know any better than I would simply had used ROMEX cable to solve this issue -- Sheathed from the basement cut-off switch box and 1" into the PVC tubing, then stripped all the way to the outdoor electrical socket. I know that some people say that this is okay but I have gone the THHN cable route due to the pipe being exposed to the sun all day.
Thanks for the consideration of this issue and I do appreciate any follow up comments.
