I just purchased a trailer that was used for dog grooming. It is fully wired with for 120 volts AC. All the wires in the breaker box have been disconnected. I have already toned the wires to identify their use. I am going to hook the trailer up to the on board Generator that came with it. I will not be using shore power only the Generator power. When I looked into the breaker box and it has 2 grounding blocks. The block on the left is grounded to the box, the block on the right is not grounded to the box. I am wondering what the block on the right would be for? I am building a food trailer so i want to make sure that everything is grounded properly. Would i connect both the ground and the white to the block on the left? Also the Generator is only a 120 volt AC output. Thank you for your help with this matter.enter image description hereenter image description here

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    A picture of the inside of the panel would help. please EDIT your question to include a picture. Guessing, so don't take this to the bank, but it sounds like the panel can support an "isolated neutral". If so the left buss bar is for ground connections and the right one is for the neutrals. we need to see the panel to be sure, so I''m not posting this as an answer. Commented Jan 10, 2021 at 15:13
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    Yes, can you post photos of the inside of the breaker box please? Commented Jan 10, 2021 at 15:55
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    @GeorgeAnderson helpful trick I only recently learned myself - if you put the word "edit" inside "[" "]" in a comment, it makes a clickable edit link. Same also works for tour.
    – Ecnerwal
    Commented Jan 10, 2021 at 17:47
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    Neutral Is Not Ground. You may be accustomed to seeing neutrals and grounds on the same bar, but that is a "special case" that only applies inside main panels. There's nothing weird about the fact that 99% of your work is in main panels, but you must still remember it's an exception not the rule. Commented Jan 10, 2021 at 18:11
  • Sorry. I just figured out how to attach a picture
    – Larry
    Commented Jan 11, 2021 at 2:52

1 Answer 1


The isolated bar is intended for Neutral.

If, like many generators, yours has ground and neutral bonded inside the generator, your generator neutral and all neutral wires go to the isolated bar, and the ground wires go to the one connected to the box.

That also sets you up properly for a "shore power" input.

Your hot feed either goes to one of the line inputs and you only use that half of the breaker spaces, or you connect your hot feed to both line inputs with a jumper, since this is 120V only, so there won't be any 240V dual-breakers. The former leaves the ability to connect to shore power (or a larger generator) "properly" and the latter does not (but will work if you are only plugging into a 120V-only shore connection.)

  • Thank you very much for your help. So, connect one side of the Generator to one side of the breaker box input terminal and the neutral to the isolated bar i will not be useing shore power at this time, just generator power. Just wondering do you know where there is a diagram for this?
    – Larry
    Commented Jan 11, 2021 at 3:04
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    Assuming the cord in your picture is connected to a normal 120V plug going to the generator, or the generator if hardwired is remotely standard, move the white wire from it to the isolated bar., NOT the second line terminal as you have pictured. It appears that the breakers are already set up for single hot operation. The cord needs to go through a knockout and be held with a clamp. The cord seems rather small - is the generator very small?
    – Ecnerwal
    Commented Jan 11, 2021 at 3:30
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    It's a good idea to confirm the ground-neutral bond. OSHA-approved generators will be bonded.. but many that are sold to the portable/recreational market, such as the popular Honda EU series inverter generators, are not factory ground-neutral bonded.
    – Greg Hill
    Commented Jan 11, 2021 at 5:11
  • Thank you.. yes the cord is connected to 110 wall outlet.. im just trying to find out what wires go where. When im done that cord will be replaced and in stalled correctly. Its just temporary. I really appreciate your help and knowledge on this. You people are great! I'll keep you posted. Thanks again LARRY
    – Larry
    Commented Jan 11, 2021 at 14:59
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    @LARRY please make sure you say "thank you" in the appropriate way for this site - click the up vote arrow next to every answer that helps you, and click the check mark next to the one that helps you the most.
    – FreeMan
    Commented Jan 11, 2021 at 16:06

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