MarkSolar
Solar Enthusiast
I'd use XHHW aluminium. It will be about half the weight and probably 30% cheaper. As mentioned it's more flexible and has tougher insulation. It's also chemical resistant if that matters in your environment.
Switching to aluminum will require increasing the wire size to keep ampacity and voltage drop the same, 4 AWG for lines and neutral and 8 AWG for ground.I'd use XHHW aluminium. It will be about half the weight and probably 30% cheaper. As mentioned it's more flexible and has tougher insulation. It's also chemical resistant if that matters in your environment.
It works if the conduit remains dry inside.I don't leave anything in the conduit. If I need to pull something later, I get a plastic shopping back (the kind you get at the grocery store), a kite string and a wet/dry vac.
suck the bag through the conduit with the vacuum. then tie the kite string to whatever muletape you are using to pull with, and pull it through.
I don't recommend this.drill holes in the bottom of the conduit if there is a water concern.
There is no PVC underground that doesn't have water in it. The only way I've found to keep water out of PVC is to use primer and cement.It works if the conduit remains dry inside.
I'd run a heavy nylon fishing line thru it first if I was to leave the conduit empty for a long time. A piece of foam works sometimes better than a plastic bag. The fishing line won't rot like string or rope, even some mule tapes.
This past winter, there was a boring company running new wires and sleeves to upgrade the utility lines to underground. Ground foreman was out mid winter for shoulder surgery. When he was back they decided to run the wire to the distribution box by my driveway that feeds 3 different acreages.
First they put a small vac on it. Kept getting water but eventually they thought it was clear. Finally, they pulled a tape thru, then went to pull the steel cable which is used to pull the wire. Had a little problem, the tape was wet from sitting overnight and snapped. Next, they came with a bigger truck mounted vacuum and sucked for half a day. Some rocks came thru and damaged the vacuum but they did get the tape thru again and pulled the steel cable thru. Finally got the winch cranked up to pull the heavy wire.
The water came from up the hill. The distribution box was at the low spot between 2 hills and when the snow melted with some rain, a large wall of water came down the draw and filled the pipe. Along with the water it carried rocks.
Did plastic shopping bags (today's flimsy type that could get sucked through conduit) exist 30 years ago?I'd love to take credit for it, but it's something my dad showed me like 30 years ago. No idea where he learned it.
But, I've seen the same process used all over the place, so it's decently well known, I'd imagine
Not sure, he used to use wadded up aluminum foil. (not tightly balled up, loosely balled, and about 2/3rd the size of the conduit. I use the grocery bags, cuz they are plentiful and I always have a dozen handy.Did plastic shopping bags (today's flimsy type that could get sucked through conduit) exist 30 years ago?
Tim. Our local journeyman/master electrician says that condensation gradually fills the conduit up. He recommends drilling the holes.I don't recommend this.
This will allow water and Mudd to enter the conduit.
Right, no shading. We have a “few” acres, so did a ground mount.Thanks Wheelman. Terlingua.…the solar capital of Texas? I imagine shading isn’t much of an issue. ?
The purpose of the conduit is to provide protection for the conductors. Underground conduit always has water in it. That's why the conductors have to be rated for wet conditions. Drilling holes just let's Mudd into the conduit.Tim. Our local journeyman/master electrician says that condensation gradually fills the conduit up. He recommends drilling the holes.
I can certainly see a case where the weep holes would allow dirt in and also allow roots to grow inside the conduit.
My area has virtually no vegetation so no roots to worry about.
I haven’t buried that much PVC conduit, maybe several hundred feet over several decades, but I’ve never had to deal with moisture inside. Interesting. Nonetheless the insulation ratings for wet environments add the insurance if the solvent joints weren’t properly connected.The purpose of the conduit is to provide protection for the conductors. Underground conduit always has water in it. That's why the conductors have to be rated for wet conditions. Drilling holes just let's Mudd into the conduit.
The greatest benefit of conduit is the ability to change or replace the conductors, at a later date.
Not going to be easy (if at all possible) with the conduit full of dried Mudd.
It's a 50/50 shot around here.but I’ve never had to deal with moisture inside. Interesting.
?
A clarification that doesn't apply to your situation specifically. If more than 3 conductors are in a conduit then the ampacity has to be derated. In this case the Ground wire(s) is not counted.
Though I don’t know if a short would burn through the conductors and the pull tape.