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Discussion Starter #1
I did a bit of searching, but didn't find exactly what I was after.

I need to install a sub panel on the opposite end of my house from the main, approximately 80' across. Ultimately, the subpanel will have a pool (120V 30A GFCI) and a hot tub (240V 50A GFCI) wired to it by the pool electrician. My main panel is mounted externally and my plan is to exit the main and go up to the attic area of the house. Penetrate the stucco on the exterior wall and run across the attic the length of the house. Penetrate the stucco again to exit on the opposite end of the house and down to the subpanel, also mounted on the primary structure. I'm looking to confirm the following assumptions before I proceed with the install:


  • Ground conductor must be insulated
  • #4 L1, L2, #6 Neutral, & #10 Ground are appropriately sized
  • Conduit is required the entire distance from the main to the subpanel
  • Metallic conduit is required
  • Ground conductor at the subpanel should be connected to a bus bar, not tied to the panel
  • No ground rods / grounding are required at the subpanel
I appreciate the help. Feel free to point out anything I may have missed.


Thanks in advance for the help.


Mike
 

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- 4/4/6/8cu would be acceptable for a 90A feeder, which should be fine. You'll need 2/2/4/8cu for 100A.

- Metallic conduit is not mandatory, unless a local written amendment requires it.
 
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I did a bit of searching, but didn't find exactly what I was after.

I need to install a sub panel on the opposite end of my house from the main, approximately 80' across. Ultimately, the subpanel will have a pool (120V 30A GFCI) and a hot tub (240V 50A GFCI) wired to it by the pool electrician. My main panel is mounted externally and my plan is to exit the main and go up to the attic area of the house. Penetrate the stucco on the exterior wall and run across the attic the length of the house. Penetrate the stucco again to exit on the opposite end of the house and down to the subpanel, also mounted on the primary structure. I'm looking to confirm the following assumptions before I proceed with the install:


  • Ground conductor must be insulated
  • #4 L1, L2, #6 Neutral, & #10 Ground are appropriately sized
  • Conduit is required the entire distance from the main to the subpanel
  • Metallic conduit is required
  • Ground conductor at the subpanel should be connected to a bus bar, not tied to the panel
  • No ground rods / grounding are required at the subpanel
I appreciate the help. Feel free to point out anything I may have missed.


Thanks in advance for the help.


Mike
I noticed that you are in Arizona. Does your attic get very hot in the summer? If so you will need to adjust your conductor sizes according to the ambient temperature.

The grounding conductor in the subpanel should terminate on a bar separate from the neutral conductor, but must be connected to the subpanel so it is grounded. These ground bars are screwed directly onto the subpanel enclosure.

If you decide to use PVC conduit you must install at least one expansion coupling.

Although a ground rod is not required for your installation, it is a good idea anyway for lightning protection since you plan on feeding an outdoor pool and hot tub.
 

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Discussion Starter #5
I noticed that you are in Arizona. Does your attic get very hot in the summer? If so you will need to adjust your conductor sizes according to the ambient temperature.

The grounding conductor in the subpanel should terminate on a bar separate from the neutral conductor, but must be connected to the subpanel so it is grounded. These ground bars are screwed directly onto the subpanel enclosure.

If you decide to use PVC conduit you must install at least one expansion coupling.

Although a ground rod is not required for your installation, it is a good idea anyway for lightning protection since you plan on feeding an outdoor pool and hot tub.
My attic is insulated at the OSB under the tile. I would guess it doesn't ever get above 90 F up there. Thanks for the info on the expansion coupling.
 

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Discussion Starter #6 (Edited)
Here's the sub panel installed. Let me know if there are any potential code violations visible/present. Thanks again for the helpful input.

Ended up pulling 4/4/4/8 and installing a 90A breaker in the main. The #4 neutral was a miscommunication, but fit.
 

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The panel is sideways. I don't think they allow that in the US. It is fine in Canada.
 

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The panel is sideways. I don't think they allow that in the US. It is fine in Canada.
Depends on installation instructions. Most panels specifically allow upside down installation, but I haven't seen one that allows sideways. Actually panels rated for wet location (outside) usually only allow upside up installation.

The bending radius of that #4 wire looks awfully small, but I'm not sure if that's a violation.
 

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Upside down is fine as the breakers still operate sideways. You guys down there have some rule that up has to be on for breakers, so sideways doesn't work for you.
 

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It's not just the handle up is on rule (240.81).

Section 240.33 of the NEC requires that enclosures containing overcurrent devices must be mounted in a vertical position unless this isn't practical.

(If mounted horizontally, the circuit breakers must still be installed in accordance with 240.81. With most panels, that means half of your slots would be un-useable.)
 

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Upside down is fine as the breakers still operate sideways. You guys down there have some rule that up has to be on for breakers, so sideways doesn't work for you.
And as long as the enclosure is rated for it. Rightside up allows of rain to run off correctly. Any other mounting would not...
 
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