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UPDATE

I was able to talk to one of my county building inspectors. I am fine to run Aluminum SER. I can run it all the way to the sub panel. I have to run fully insulated copper from the sub panel to any pool equipment. I think I got everything answered now.

UPDATE: Of the questions below, the one I am most concerned about is the way that I run the 1-1-1-3 Aluminum SER cable above the finished basement ceiling. Will it pass inspection?

I have been trying to contact my county electric inspector to ask this question without luck (we have a 30 minute window in the morning and nobody ever answers the phone) so I am looking for advice here. I want to make sure I am following relevant NEC code and it's likely to pass inspection.

For all of these questions - I am located in Warren County, Ohio.

I need to run electric from my main load center to the pool load center. Here is my current plan.

Background - My main load center is in the basement. My basement is fully finished with drywall ceilings and very limited access. I do have a way to get access from a small unfinished area in the middle of the basement where the mechanical equipment (HVAC, Water Heater, etc) are located. I will cut access where needed but I want to minimize repairs to the drywall if possible (e.g. I don't want to take down entire strips to do this if possible)

  1. I am running an 80AMP circuit to the pool load center. I won't need that much initially, but I want to make sure I have capacity for a heat pump in the future if desired.
  2. I plan on running 1-1-1-3 Aluminum SER from the main panel to a junction box mounted on the inside of the house wall.
  3. Within the junction box I will transition to 3-3-3-3 Copper THHN/THWN individual wires using AL/CU rated splicers appropriate for the wire guage.
  4. I will drill a hole from the basement wall through to the outside and run schedule 40 Schedule 80 conduit (a 1.25" LB conduit body and 1.25" conduit) up to the pool load center through which the 3-3-3-3 copper will be run.
  5. Within the pool load center I will be installing 1 240V 20AMP GFCI breaker for the pool pump (wired through the timer - it's a Intermatic panel with a 240V timer), as well as 1 15AMP GFCI for the lights (wired through a switch in the panel if desired or an external switch) and 1 15AMP GFCI for a convenience outlet.

I don't think I have any questions on the pool side of the wiring. I understand the separate equipotential bonding I need to perform and wiring of the pump, lighting and salt/chlorine generator is pretty straight forward.

My questions are:

  1. Is it permissible to run SER cable within the basement ceiling without drilling and running through the middle of every floor joist? From the unfinished portion I do have access and the way they did the ceiling I can fish the cable over to the main load center and over to an area where I may have to cut an access to finish fishing it to the wall where I will install the junction and an access panel.
  2. What type of attachment to the floor joists is acceptable in this circumstance? I believe I can attach cable of this size right to the underside of the joists on the perpendicular rather than having to drill and staple to the joist face where it's parallel?
  3. Is is permissible to run Aluminum within the dwelling and convert to copper before going to the outside (corrosive) environment as I have described?
  4. Do you see any other concerns?

I thank you for your time and helping me with this!

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    Connecting the SER to copper will require the proper connectors or you'll end up with a fire like they did in the 70s. Consider running AL outside, too - eliminates the issue and likely will be cheaper. You'll need Sch 80 conduit for physical protection of the wires, especially near the ground where they'll be susceptible to physical damage (mowers, weed whackers, kids, shovels, etc.). I'm sure someone will be along soon with code cites and other concerns. Please edit your question to indicate what county/state, as code requirements vary.
    – FreeMan
    Commented Apr 29, 2022 at 14:13
  • Thank you for your response @FreeMan. My understanding is that Aluminum is explicitly disallowed at the equipment side because of the corrosive environment. I will update my conduit on the outside to be Schedule 80. These are the splicers I was planning to use amzn.to/3vWncV3 I am in Warren County, Ohio (I updated the question with this info too) Commented Apr 29, 2022 at 14:53
  • The #1Al and #3Cu are appropriate for 100A. (you may be reading out of the wrong column on Table 310.15(B)(16).). If you only need 80A then #2Al and #4Cu will suffice. Polaris connectors are rated Cu/Al but are pricey, so worth looking for a way to avoid. The sub isn't supposed to be that close to the pool that chemicals would matter, remember the lugs and neutral buses inside it are aluminum! but that really is an AHJ question. They do make rubber coated FMC rated for outdoors. Commented Apr 29, 2022 at 19:01
  • Thanks for the reply @Harper-ReinstateUkraine. You're right about the ampacity. I wasn't reading out the wrong column so much as putting a nanny breaker on it. The wife has mentioned a hottub in the future and I thought I might as well size the wires to the capacity. The sub panel is rated for 100amps so I should just put a 100Amp breaker in. Commented Apr 29, 2022 at 20:29
  • @Harper-ReinstateUkraine - The pool contractor is the one that told me that I needed copper on the outside. It isn't "that close" to the pool, but it is that close to the pump, filter, salt/chlorine generator. He's done a lot of installs here and said that inspectors will require all insulated copper from the sub panel to the interior of the house including the ground wire. He did say that the sub panel must be installed > 5 feet from the equipment but they still consider it to be a corrosive environment if the inspector wants to be strict. If the county would answer the phone I would ask! Commented Apr 29, 2022 at 20:32

2 Answers 2

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Connecting the SER to copper will require the proper connectors or you'll end up with a fire like they did in the 70s.

Consider running AL outside, too - eliminates the issue and likely will be cheaper.

You'll need Sch 80 conduit for physical protection of the wires, especially near the ground where they'll be susceptible to physical damage (mowers, weed whackers, kids, shovels, etc.).

2

After discussion with a local county inspector I was able to answer the following

  • Running Aluminum SER of the size I was targeting 1-1-1-3 was acceptable and I could fish the cable and suspend it under the floor joists in my finished basement without having to cut out all the drywall and drill holes in every floor joist.
  • I did not need copper on the outside to the sub panel. Aluminum all the way to the sub panel was acceptable.
  • From the sub panel to any equipment I did need to run all insulated wires in conduit.
  • I will be running from the house to the sub panel using schedule 80 conduit.

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