I just installed a new service entrance on my garage. This is a farm
and each building connects to a pole with a 400A main shutoff. I did
however put a 100A box with it's own main in the garage. Anyhow, the
wiring is not the problem. That works fine.
The problem is the PVC entrance head. I used 1 1/4 pvc and matching
head. These heads have three pre-made holes. Each hole is about 3/4
inch in size. The wire is #4 copper which is about 3/8 dia. So, what
I got is a huge air leak coming into the breaker box. Yes, this is
only a garage, but the same heads are used on houses too, and I did
try to make this garage air-tight when I rebuilt it, since I need to
work in there in the winter and I use a space heater. Besides the air
leak, I can see that head getting filled with wasps in the summer.
I went to the clerk at the Menards where I bought the supplies. The
clerk was clueless. I had to show him a service head on the shelf
before he knew what I was talking about. Then he said to caulk it
shut, but cautioned me to use fireproof caulk, saying "the wires get
real hot". OK, that was a waste of time..... If the wires got that
hot, the pvc would melt.... I asked for the manager who told me there
is nothing made to seal the holes and they are designed to keep the
wires cool. So much for that advice.....
Anyhow, I am still facing the air leak and wasp nest problem. Does
anyone have any suggestions how to plug the gaps around the wires?
I did consider using silicone caulk, but I think the wires do need to
flex from temperature changes and should not be sealed that tight. My
only other idea is to stuff fiberglass insulation in there. Anyone
got any other ideas?
Thanks in advance