Solar Bonding and Grounding Confusion in New Installation

Danyael
Danyael Registered Users Posts: 1 ✭
in Solar Information links & sources, event announcements #1

Hello everyone, I am currently working on a new solar installation project and I have some confusion regarding solar bonding and grounding. I understand that both are important for safety, but I am not fully clear on how they differ in practical implementation. From what I’ve learned, bonding connects all metallic parts to ensure they are at the same electrical potential, while grounding provides a path to safely discharge fault current into the earth. However, I’m unsure about best practices.

Can anyone guide me on:

  1. Proper bonding techniques for solar panels and mounting structures
  2. Grounding requirements for residential vs commercial systems
  3. Common mistakes to avoid during installation

Any advice, diagrams, or real-world experience would be really helpful.

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  • MGar
    MGar Registered Users Posts: 23 ✭✭
    #2

    I ground the panel frames. To a good earth ground.
    Add a simple disconnect switch near the panels, and a Surge Protectors for the + and - wires at the switch box, underground wire if possible then a Surge Protector again for backup(optional), then the DC breaker.
     They sell varies voltage Surge Protectors,  most SCC have these built in as last resort.

    Always disconnect the switch when working with the MC4 connections 


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  • SumPower
    SumPower Registered Users Posts: 134 ✭✭
    edited April 2 #3

    1. Proper bonding techniques for solar panels and mounting structures.

    Use UL listed devices that have passed testing to achieve the listing. Self piercing solar panel clamps are a good example. The bonding is achieved when the piercing portion of the panel hold down clamp is properly torqued per installation instructions. 
    For ground mounts. When you use UL listed devices to bond the panels to the panel mounting rails, then you only need one #6 bare copper conductor run to the first combiner box or junction box from a panel rail, at the combiner box or junction box the Equipment Grounding Conductor (EGC) can be down sized and run in conduit to the MPPT charge controller ground bar. The EGC needs to be run in conduit with the PV conductors. 

    The EGC needs to have continuity all the way from the solar panels to the AC distribution panel. Which bonds it to ground there because of the ground rods being connected to this point also.

    Ground rods at a solar ground mount are not required by code.

    2. Grounding requirements for residential vs commercial systems.

    Are the same, 2 ground rods driven at least 6 feet apart. With a #6 bare solid copper conductor running from the ground bar in the AC distribution panel in a continuous run to the ground rods (no splices in it).
    The neutral and the ground shall only be bonded together in one location, this is typically done at the first disconnecting means. 
    In Commercial structures grounding with a #4 bare copper UFER is sometimes specified. The UFER ground is landed on the ground bar in the AC distribution panel.

    3. Common mistakes to avoid during installation.

    Not using equipment that is UL listed for the purpose. 
    Installing a ground rod at a ground mount installation, my opinion.



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