I talked with the electrical inspector. The electrical wires and the water pipe (Pex) can be side by side, whether the wires are UF-B or THWN in conduit. We're like the idea of putting the wires in conduit for all the reasons already stated. When our basement was poured, we had the contractor put in a 2" PVC sleeve for the waterr line, thinking that would suffice for both water and electrical. Now we realize that it isn't large enough for both 1" Pex (1 1/8" OD) and conduit (we don't want to try pulling 5 wires through a small diameter conduit (Dear husband wants to use 2").
So we're thinking of doing it like this:
Install 2" PVC conduit for individual THWN wires - 1 each black and red 10 gauge, 1 green 12 gauge, and 1 each black and white 14 gauge - 5 wires in all. The conduit will be laid in the ditch beside the Pex water line. At the junction with the house, we will only feed the Pex through the 2" PVC sleeve that is through the basement wall. Where the electrical conduit intersects the basement, we'll add a long sweep elbow to bring it up above grade so that the wires can be fed through the band, above the basement wall. (Our basement wall has 2" foam insulation and stucco on the outside so we don't want to drill another hole through that.)
My questions concern the place where the wires enter the house. From what I understand we can put a LB fitting at this location to have a waterproof elbow where the wires turn to enter the house. Do these wires then go to an interior junction box mounted inside on a joist? Is this acceptable to have splice in the wire at this location or should the wires be continuous all the way to the pressure tank? (I've also seen mention of an exterior junction box that could be used in lieu of the LB fitting and interior box, but the same question concerning the splice applies.)
Since we're running wires for both the pump and the light, do we need to have a separate junction box for each or will the one box suffice?
One more question... does anyone use lubricant on the wires for easier pulling? If so, what do you use?