FordTruckWench
Well-known member
I'm helping friends run more power to their garage.
The situation: Detached garage 26 feet from a house. Main panel is surface mounted at the corner of the house - so about 28 feet to the garage. There is a foundation pier for a deck support right on the straight line route. Currently wired via 3/4 buried conduit - steel at the house, and plastic at the garage end.
Option 1: A PVC 90 elbow, two 10' sticks of schedule 40 PVC, a 45 elbow (to dogleg around the deck pier), a partial stick of schedule 40, and another 90 elbow underground. Then aboveground at each end a half stick schedule 80 PVC riser, topped with a PVC male threaded adapter at the main panel end, and an LB conduit body feeding through the wall into the back of the subpanel.
Option 2: Underground the same as option 1. Each 90 elbow is topped with a male threaded adapter, then a steel coupling, and then a half stick of rigid steel or IMC. This connection is underground and uses the factory threading on the steel conduit. Male PVC into female steel keeps the plastic from eventually splitting. Both risers are topped with a compression connector. One goes into the main panel, the other threads into a metal LB.
Both ends of this conduit run are in high traffic areas. There's some steel conduit on site. It looks good despite being 50 to 65 years old. There's also PVC that's perhaps 30 years old. Although this conduit itself is not broken, it looks dumpy, floppy and is sagging. All PVC retaining straps and weatherproof receptacles were broken.
Which option should we choose: Continuous PVC? Or transitioning to metal aboveground?
Also what size? At minimum we'll run copper THWN 6-6-6-10. I am suggesting 4-4-4-8. The 6ga could in theory be in 3/4. The 4ga fits in 1 inch, except the schedule 80 needs to be 1 1/4. I am leaning towards 1 1/4 but how about 1 1/2? (The panel knockouts fit a max of 1 1/2.)
The situation: Detached garage 26 feet from a house. Main panel is surface mounted at the corner of the house - so about 28 feet to the garage. There is a foundation pier for a deck support right on the straight line route. Currently wired via 3/4 buried conduit - steel at the house, and plastic at the garage end.
Option 1: A PVC 90 elbow, two 10' sticks of schedule 40 PVC, a 45 elbow (to dogleg around the deck pier), a partial stick of schedule 40, and another 90 elbow underground. Then aboveground at each end a half stick schedule 80 PVC riser, topped with a PVC male threaded adapter at the main panel end, and an LB conduit body feeding through the wall into the back of the subpanel.
Option 2: Underground the same as option 1. Each 90 elbow is topped with a male threaded adapter, then a steel coupling, and then a half stick of rigid steel or IMC. This connection is underground and uses the factory threading on the steel conduit. Male PVC into female steel keeps the plastic from eventually splitting. Both risers are topped with a compression connector. One goes into the main panel, the other threads into a metal LB.
Both ends of this conduit run are in high traffic areas. There's some steel conduit on site. It looks good despite being 50 to 65 years old. There's also PVC that's perhaps 30 years old. Although this conduit itself is not broken, it looks dumpy, floppy and is sagging. All PVC retaining straps and weatherproof receptacles were broken.
Which option should we choose: Continuous PVC? Or transitioning to metal aboveground?
Also what size? At minimum we'll run copper THWN 6-6-6-10. I am suggesting 4-4-4-8. The 6ga could in theory be in 3/4. The 4ga fits in 1 inch, except the schedule 80 needs to be 1 1/4. I am leaning towards 1 1/4 but how about 1 1/2? (The panel knockouts fit a max of 1 1/2.)
240V 30A on 10ga wires without a ground. And no, neutral and ground were not bonded in the old panel - the panel simply has(had) no provisions for any ground wiring at all! The intent of this exercise is to handle a 240V compressor and/or weld thicker material. The 10ga hookup is obviously not original - I don't know how it would have been connected when the property was built.