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I am looking to bury both my main power line and my ethernet lines. I already started the process on both.

When I purchased my home, the meter was in the back of the house with overhead lines, but I wanted to move the meter to the side of my home and bury the lines, as this would allow me to extend my deck across the back of my home. I installed the new meter and connected my electrical panel to it. The electricians added a "jumper" cable to the old meter area temporarily. My local electrical utility (DTE Energy, Michigan) will remove the overhead line, the temporary jumper, the old meter, and bury the line to the new meter, adding some green box in the back corner of my property.

Simultaneously, I added a new coax cable for internet to the side of the house as well. I want this buried for the same reason, so I can extend the deck along the back of my home and have a nice clean buried cable look.

I also plan to add landscape lighting and a sprinkler system for my landscaping, with the possibility of adding outdoor speakers. So, I need to keep in mind those things will also need conduit.

I'm not sure the best path to trench for the power line and ethernet lines. I've added photos of my current situation for clarity. My worry is making sure high voltage is not going to interfere with low voltage and I also want to avoid having to tear apart my landscaping if access is ever needed. Though, what is the likelihood of something happening where the buried lines will need to be accessed? If it is practically zero, maybe it's best to bury them along the fence line right behind my landscaping? Also, does it make sense to trench, bury the power lines, then have a shallower trench for my ethernet lines above my power lines? I know I need to keep them around a foot apart (high voltage, low voltage).

I'm also clueless on arbor vitae and various types of trees that I would worry about having buried lines nearby. Will they eventually grow roots so much they interfere with or ruin my buried lines?

One other thing to note, even though my side neighbor (not back neighbor) is planning to add a garden, it won't extend all the way to the corner, so I'm going to ask him if I can put the green box required for the power line on his property at corner near the utility pole, as one of the other reasons I wanted to move my meter and ethernet access was to avoid having the utility company going into my back yard and he doesn't plan on fencing his back yard up, nor does the neighbor behind him.

Overhead View

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    One word: Conduit Commented Sep 13, 2023 at 17:03
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    I read about 6 questions in your post. You will get better, focused answers if you can narrow down exactly what you want help with.
    – spuck
    Commented Sep 13, 2023 at 17:11
  • "I know I need to keep them around a foot apart" - citation? Article 800 is for aerial : Is there a required spacing between where high and low voltage lines attach to a house?. Nobody cited any code so +1.
    – Mazura
    Commented Sep 14, 2023 at 3:21
  • "(H) Where Protected [] Class 2 and Class 3 circuits shall be permitted to be installed together with the conductors of electric light, power, Class 1, non—power-limited fire alarm, and medium-power network-powered broadband communications circuits where they are installed using Class 1 wiring methods in accordance with 724.46 and where they are protected by an approved raceway." up.codes/viewer/minnesota/nfpa-70-2023/chapter/7/…
    – Mazura
    Commented Sep 14, 2023 at 3:31
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    Nitpick: Coax cables are NOT Ethernet cables. They may be used for internet access, but they are not the same thing, and the electrical differences potentially matter because they respond differently to different types of electromagnetic interference. Commented Sep 14, 2023 at 11:15

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Many of your questions are moot as the power company will most likely come, trench to the depth they want. Put the box needed where they want it. ( For some corporate legal reasons it shouldn't go on your neighbors property if you wanted the cable buried.) Most all property have "Utility easements" so the utility companies can do what work they need to do. You cannot remove that easement from your property, so forget about telling the power co. it cannot come in your yard. ( utilities do try to respect your property as much as possible.)

Coax cable, ethernet, sprinkler wire. low voltage lighting do not have to be buried deep as does power cable. They also should never share a trench even at different depth. The low voltage stuff can be just a few inches under the ground.

Will you have to ever dig it up? The power line, most likely not in your lifetime. the low voltage stuff, maybe. That's another reason it should be very shallow. Most of the time it is abandoned and new lines are run if needed.

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First of all, I've never seen Ethernet run from a pole to a house. So, the coax that comes from the cable provider uses a point-to-point communication standard different than Ethernet. Ethernet is the collection of local areal network standards that apply to networking using cabling and wireless in the house on the other side of the modem/router. That being said, the cables themselves are the Cat standards, like Category-6. Unshielded Cat6 in particular is vulnerable to EM that comes off of power circuits, so where it is used, it is run perpendicular to power which has something to do with the right-hand rule and how E&M work. Most people today just go wireless across a smaller residence (say 1500 to 3000 square feet) to save the hassles of cabling which can be involved with fishing in stud bays, punching down the RJ-45s in plates, and putting holes in places all over the house.

Coax, which is what cable data services run on from the pole to the modem, itself is shielded, but there are variety of shieldings available. For instance, read this supplier's overview on shielding varieties. If you're going to trench, I suspect that the low-voltage would be best off not only being high-quality and shielded, but laid in steel conduit at a small distance from the power. Steel conduit is known to reduce EMF effectively. Lastly, if you do run cable without conduit to protect it from EM and physical damage, make sure you include a shield above it so that an unsuspecting gardner or other digger doesn't accidentally sever the line. Aluminum passivizes and it comes in thicker gauged coils used for trimming in roofing.

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    Sorry, I see the confusion, I typed ethernet when I meant to say internet, as in coax, for the buried line for cable services.
    – myermian
    Commented Sep 13, 2023 at 19:03
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I tend to agree with RMDman that the route the power cable takes is very likely to be a straight line. Your power utility has to pay for and maintain this cable, it's not cheap cable (go look up the price per foot of 2/0 cable) and they will not add more length if they can help it.

Cable companies, by contrast, don't have anywhere near as expensive

You do not, however, want to bury your cable near the power lines. It can intersect it at points, but the power lines can cause all sort of signal degradation. Your cable company will probably keep their wires close to the fence line and then cut straight across for that reason. I suggest you do the same if you're burying them directly.

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  • Real world experience: 480V/400A power bus. Somebody tossed a 10-baseT cable over it. Everything downstream was flaky until we found what had been done and moved it. Commented Sep 15, 2023 at 2:53
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I buried 240 volt 30 amp power and Ethernet cable together for a run of over 300'. The latter was roughly a foot above the power lines.

If the load is not significantly unbalanced on the power line, the field should largely self cancelling.

Furthermore, the pairs in the CAT5 Ethernet cable are mostly balanced.

Just my experience.

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  • I have POE (Power Over Ethernet) cameras on the perimeter of my property. I simply put in a 1" plastic conduit for that, it works without any problems. I oversized it deliberately and added a second cable just in case, the additional cost is much less then digging it up.
    – Gil
    Commented Sep 15, 2023 at 15:32

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