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Electrical wiring for mini split AC and sub panel - Potential problems with inspection?

DrVlikhell

Active member
Joined
Sep 9, 2020
Messages
29
Location
Florida
First off I'll say that you guys are amazing and this forum is a fantastic resource. I've gotten an incredible amount of information and answers here without even having to post any questions. But now I do have some questions about some special aspects of my project.

Second off, my apologies, I'm long winded and don't know how to write short questions. I've tried, but every time it just feels like I'm leaving out important information.

I need to install a sub panel for some mini split AC units. My meter is on a pole behind the house and it has a small section for breakers on it which I was going to use to feed the sub panel. I dug a trench from the pole to the house about seven feet long and 22" deep. However, there are some things which cross the trench that I'm afraid could become a problem if an inspector sees them.

#1 There is a septic pipe that was just peeking through the dirt even before I started to dig. It was permitted and installed in 1984, but I'm guessing it was never inspected. It can't go any deeper because of the distance and angle it needs to reach the septic tank. It goes into the shed for a previous washing machine hookup and I plan to use it for a water softener drain. I'm afraid it could cause an inspector to have a fit and demand that it be set deeper in the ground with a lift pump, or be removed. Both of which are undesirable and expensive. It's been fine for 40 years, I'd prefer to leave it alone and just cover it up with some dirt and grass like it used to have.

#2 There is a wire going from the panel on the pole to an in-ground well pump. I'm guessing it's a direct burial cable because there is no conduit for it except for where it goes down the pole. It's also nowhere near 18" deep. I'd guess maybe 6 to 8", there's some erosion going on there so maybe it was originally 12". It's been there since the 60s so there may not have been code for it back then. I'm afraid an inspector could require me to re-run that wire, which would be very expensive since there are four very large trees in that area between the pole and well and I'd have to hire a power trencher/excavator to get through the roots. I believe it currently goes under the length of the concrete driveway and concrete shed foundation so I can't just dig it up and set it deeper where it sits, it would have to be all new.

#3 There are some wires in conduit that's also going to the shed. It was permitted in 1984 along with the septic and water going into the shed. It's not at 18" depth either, it sits just on top of the conduit for the feeder cable that goes into the house... which also isn't 18" deep. I'm guessing these won't be an issue since they're probably grandfathered in and I'm not even sure that Florida had adopted the NEC in the 80s, or the 60s. But if they are an issue, having to do anything to the main house feed would be terribly expensive.

Do you guys think these issues could turn into massive problems by an inspector requiring them to be changed even though they have no thing to do with the electrical permit, except that the new electrical lines run underneath the above mentioned issues?

And, the painful question, is the likelihood of an inspector making an issue of them high enough that I should scrap the trench all together? It was three painful days of digging under everything, and digging under roots that were too big to cut, and digging up the five telcom wires, three cable wires, fiber wire, etc. I even got the conduit assembled in the trench under all that mess, which was one of the hardest things I've done. But tonight when I was looking up when to call for an electrical inspection I read about a whole bunch of people having issues with an inspector citing things outside the scope of the permit as failure points requiring remediation. And well, I'd rather ditch my work, cut up the conduit and start over than have to deal with any of the above mentioned points if they were cited as needing to be changed.

If I scrap the trench, I could run the sub panel off the panel in the house, I'd need another 30 feet of wire and some more 1" conduit and fittings. Then I would run it down into the crawl space under the house, along the underside of the house and out to the back. I would still have to trench along the back of the house to get to where the AC condensers will sit, but there's nothing egregious there. There is no attic, if you're wondering.

Let me know what you all think, and congratulations if you read the whole thing!
 
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dcg9381

Well-known member
Joined
Jun 20, 2018
Messages
11,767
Location
Austin, TX
#1 - Throw some dirt or sod on it.
#2 - I've never seen them dig up pipes or wires on items unrelated to inspection and check for depth.
#3 - these are buried too, right? Again, why would they check depth?
 

MerlinsBeard

Well-known member
Joined
Mar 27, 2020
Messages
398
Location
MD
When I buried my conduit, the inspector said that I could have two site pipes that rested on top on the conduit. A site pipe is basically a 4' pvc conduit piece with a cap to keep water out that vertically rested on top of the conduit in the trench that they can put a tape measure down. They can indirectly measure the burial depth by subtracting the length of pipe above ground from the measurement from the top of the pipe to the top of the conduit.

I also took pictures but the inspector didn't need them. You can contact your AHJ and see if this is viable for your situation if you want to hide unsightly past work.

You can take pictures too if more evidence of the conduit is desired. I would use a yard stick and ruler to show depth of conduit in a couple places, or more if the conduit is longer. Good luck!
 
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DrVlikhell

Active member
Joined
Sep 9, 2020
Messages
29
Location
Florida
#1 - Throw some dirt or sod on it.
#2 - I've never seen them dig up pipes or wires on items unrelated to inspection and check for depth.
#3 - these are buried too, right? Again, why would they check depth?
Everything is exposed because they all cross my trench at some point so an inspector doesn't need to dig anything up, it's all right there and visible.
When I buried my conduit, the inspector said that I could have two site pipes that rested on top on the conduit. A site pipe is basically a 4' pvc conduit piece with a cap to keep water out that vertically rested on top of the conduit in the trench that they can put a tape measure down. They can indirectly measure the burial depth by subtracting the length of pipe above ground from the measurement from the top of the pipe to the top of the conduit.

I also took pictures but the inspector didn't need them. You can contact your AHJ and see if this is viable for your situation if you want to hide unsightly past work.

You can take pictures too if more evidence of the conduit is desired. I would use a yard stick and ruler to show depth of conduit in a couple places, or more if the conduit is longer. Good luck!
Thank you for the sight pipe suggestion! That will work perfectly if they agree to it. I emailed them this morning asking if that is permissible. I called but their phone system kept telling me to call back between 8am and 5pm... even though it was already 9am.

While drafting the email it also occurred to me, what would they do if I had used a hydro-bore to bore horizontally under all the existing conduits and wires? So if they tell me sight pipes are not allowed, I'll just fill in the middle and tell them I used a hydro-bore on that section instead of having to deal with digging through the mess.
 
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DrVlikhell

Active member
Joined
Sep 9, 2020
Messages
29
Location
Florida
So the inspectors office replied by email and said that inspection tubes are acceptable, but they didn't answer my question as to where they wanted them or how far between. But at least I have it on email record that I asked and they said it was ok to do it. Thanks again for the suggestion.
 
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