Grounding Question - eviltoast

I recently had a lighting strike and lost about $1000 worth of equipment. I’d like to reduce the chance of that happening again so I’m looking for advice.

I have a UDM in my house, with a 125 foot run underground in conduit to my barn. In the barn, I have a POE switch that feeds 10 cameras and an Ubiquiti AP. I’d like to add a ground somewhere. I just purchased a surge protector with ethernet for the barn, since the switch is currently plugged in directly to an outlet and should be protected anyway. I also bought this from APC for my equipment in the house. I was going to install that between my UDM and POE switch in the house, then ground it to an outlet.

I’m reading so much information about how to go about this. My barn is powered with 220v from my house, so 4 wires go to the barn H/H/N/G. the ground on the barn is the same ground as the house. If I use both devices can that create a ground loop in the event of a surge? I’m also reading that I can use the APC at any point on my network to provide protection. Is this correct?

Please don’t suggest fiber runs, as the cable is already run and I don’t plan on redoing it. Thank you all in advance.

  • Thesonomakid@alien.topB
    link
    fedilink
    English
    arrow-up
    2
    ·
    1 year ago

    You know that depending on the optical cable being used, grounding is still very much required, right? If this were my project and I was running underground cable to a barn, I’d use armored fiber cable to prevent rodent damage. Even if the cable is in conduit. Gophers and moles are the worst. I’ve had them chew through armored and loose tube fiber that was in conduit - which is why I will always go with the harder to destroy stuff.

    There is a lot of conductive fiber optics cable, with armored being just one type. Hence the reason NEC § 770.100 requires conductive fiber optics cable be bonded. We know it’s not the fiber that is the problem - it’s the metal that is part of the cable’s construction that will conduct electricity.

    • elgavilan@alien.topB
      link
      fedilink
      English
      arrow-up
      1
      ·
      1 year ago

      The difference between running cat 6 and what you’re talking about is that armored fiber optic cable does not have to be electrically connected to the equipment at both ends. Ground loops and lightning propagation isn’t a problem with fiber, conductive or not.

      • Thesonomakid@alien.topB
        link
        fedilink
        English
        arrow-up
        1
        ·
        1 year ago

        Depending on your local building codes and whether they adopt the NEC for electrical safety, bonding some types of fiber is not an option, it’s required. For reference, see NEC § 770.100. Notice the use of the words “shall be bonded or grounded”.

        The advice being given by some posters is to go with fiber like it is some way to get around bonding/grounding requirements. Thats not entirely true. Depending on the type of fiber, it must be bonded as fiber often has metallic tracer wire and armor that is part of its construction.

        Because OP mentioned that it’s an underground run between a barn and a house, I would personally use armored cable. Rodents will eat through conduit and cable. I’ve replaced and repaired miles of feet of cable due to rodents - even armored cable in conduit. Rodents are persistent.