snorky18
Well-known member
I'm working on determining the best way to run wire to a subpanel in my garage.
Naturally, my main panel and service entrance are on the opposite end of the house from the garage. Total wire length will be right at 60', run along the ceiling of my basement.
The path for the wire will be from the main panel in my mechanical room, up to the ceiling (exposed joists 10' off the floor), then along the ceiling, through one block wall into the ceiling over my finished basement area (still 10' off the floor, but I have to contend with the drop ceiling that's about 8' off the floor), through another block wall into the garage, then immediately turn 90 degrees downward into the garage subpanel.
There's really only two places this run NEEDS to be in conduit for protection from damage. The first few feet above the floor in my mechanical room, and the drop into the garage. Both of those areas are located on exposed concrete block walls.
The biggest electrical use I should ever see at one time would be 25 amp 240V compressor kicking on the same time as a 200amp buzz box is running (50 amps peak?). I'd really like to have at least ~80 amps available out there.
1/0-1/0-1/0-2 SER would get me 100 Amps and runs ~2/ft locally
2-2-2-4 SER would get me 75 amps and runs ~$1.50/ft locally
I was initially thinking I would run 1.5" conduit and 2-2-2-4 MHF, but that's a lot of conduit, and a lot of objects to dodge (two different HVAC linesets, tons of existing wiring, some plumbing, and probably some more stuff over that drop ceiling I haven't even noticed yet.)
What I think would be easiest, and most cost effective, would be to run SER from the main panel all the way along the ceiling of the basement to the backside of the garage wall, where it would run into a junction box.
From the back junction of the box would be a short conduit run, through the block wall, turn 90 degrees down with a LB, and drop straight into the subpanel. That would be maybe 7 or 8 feet of wire, so I'd be happy to use copper for that short a length so it would be easy to work with in the panel.
The SER would be a lot cheaper than conduit+wire, and a million times easier to route around all the obstacles. I'd still have both drops from the ceiling to the panels in conduit for protection from damage.
So two questions:
1) Any problems with this approach?
2) How would I go about splicing the SER to the THHN in the junction box? I'm thinking I'd have to have a massive junction box for that SER coming in, and some sort of connectors rated for AL and CU use (Ilsco Cleartap? polaris connectors? Split bolt with spacer?)
Naturally, my main panel and service entrance are on the opposite end of the house from the garage. Total wire length will be right at 60', run along the ceiling of my basement.
The path for the wire will be from the main panel in my mechanical room, up to the ceiling (exposed joists 10' off the floor), then along the ceiling, through one block wall into the ceiling over my finished basement area (still 10' off the floor, but I have to contend with the drop ceiling that's about 8' off the floor), through another block wall into the garage, then immediately turn 90 degrees downward into the garage subpanel.
There's really only two places this run NEEDS to be in conduit for protection from damage. The first few feet above the floor in my mechanical room, and the drop into the garage. Both of those areas are located on exposed concrete block walls.
The biggest electrical use I should ever see at one time would be 25 amp 240V compressor kicking on the same time as a 200amp buzz box is running (50 amps peak?). I'd really like to have at least ~80 amps available out there.
1/0-1/0-1/0-2 SER would get me 100 Amps and runs ~2/ft locally
2-2-2-4 SER would get me 75 amps and runs ~$1.50/ft locally
I was initially thinking I would run 1.5" conduit and 2-2-2-4 MHF, but that's a lot of conduit, and a lot of objects to dodge (two different HVAC linesets, tons of existing wiring, some plumbing, and probably some more stuff over that drop ceiling I haven't even noticed yet.)
What I think would be easiest, and most cost effective, would be to run SER from the main panel all the way along the ceiling of the basement to the backside of the garage wall, where it would run into a junction box.
From the back junction of the box would be a short conduit run, through the block wall, turn 90 degrees down with a LB, and drop straight into the subpanel. That would be maybe 7 or 8 feet of wire, so I'd be happy to use copper for that short a length so it would be easy to work with in the panel.
The SER would be a lot cheaper than conduit+wire, and a million times easier to route around all the obstacles. I'd still have both drops from the ceiling to the panels in conduit for protection from damage.
So two questions:
1) Any problems with this approach?
2) How would I go about splicing the SER to the THHN in the junction box? I'm thinking I'd have to have a massive junction box for that SER coming in, and some sort of connectors rated for AL and CU use (Ilsco Cleartap? polaris connectors? Split bolt with spacer?)