How to run SER cable to garage sub panel and finish ceiling

[gorms]

I am in the planning stages of finishing my garage. There is some old drywall in places that I have begun to take down but no ceiling (just exposed joists). There is electrical conduit running diagonally under the ceiling joists from the meter socket/main breaker on the outside of the garage to what is technically a sub panel at the back of the garage (no main breaker) that feeds the whole house. Also, there is a natural gas line running along the wall as shown and then across the joists, but based on my measurements, it is slightly above the bottom of the joists so could be within the ceiling.

My two part question is:


1) How would you guys suggest replacing the conduit so that is not exposed?

The meter socket is 100A and upgrading to 200A would require trenching a new underground cable from the POCO so I will not do that now. However, I would like to upgrade the rest of the wiring to support 200A in the future (electric vehicle, solar, who knows). Initial plan is to run new SE type R cable from the meter socket behind new drywall, across the roof rafters, and down the far wall to the sub panel and install a new 200A sub panel. It would go up through a hole in the top wall plate, mounted externally to the rafters where it won't be seen above the ceiling, through holes in the rafters where it would be seen so its behind drywall (see ceiling design attachment), and straight down to the sub panel. Is this to code for mounting SER cable? I am in the Bay Area, CA.


2) How to finish the ceiling?

The door to the house in the garage starts 14" off the floor so the top of the door is just below the ceiling height. I'm considering bringing the ceiling just far enough to encase the gas line (add a new ceiling joist just in front of it) and then drywall up to the eve of the roof the remainder of the way. This will create headroom above the house door and allow storage above the ceiling. Is this a reasonable solution?


Please see the CAD models below with notes. If they must be downloaded I will try to figure out a way to make them viewable in this thread. Thanks.

 

[gorms]

I have linked the images hoping that I will get some responses. I'm concerned about limitations of running SER cable. I know there are limitations about the length that can be within thermally insulated walls (10ft or 10% of length, whichever is less). I may have to not insulate the house side wall.

 

[Taildragger]

Not an electrician, but I was under the impression that SER was used from the service entrance to the meter socket on the POWCO side.

 

[gorms]

Because I have the main breaker at the meter socket, my distribution panel is technically a sub panel and so neutral and ground must be separated, requiring SER. That's my understanding anyway.

I spoke to an electrician who recommended keeping the sub panel at 125A and if upgrading to 200A service in the future, tie anything additional into the main breaker panel (EV charger, solar). This may keep the SER wire gauge to something smaller and make for easier routing.

 

[pattenp]

Using SER to feed a subpanel is fine. As you said if SER is run within insulation it is limited to be sized by 60 deg.C, otherwise it's 75 deg. C. And you are also correct about the 10% limit of run within insulation at a max of 10ft. Example is if you have 50ft of SER and if more than 5ft of it is within insulation then you are limited to 60 deg.C sizing.