Important wiring instruction for split phase inverter chargers with floating neutral

Important wiring instruction for split phase inverter chargers with floating neutral

You may have come across the terms “floating” and “bonded” neutral. While they sound obscure to most people knowing little about electrical engineering, they are an important factor when hooking up inverter chargers.

For Sigineer Power’s split phase inverter chargers, they are NOT UL1741 listed, the output floating neutral is NOT bonded with the ground.

It MUST be separated from the earth ground.

The NEC calls this a “Floating Neutral” and “Isolated Grounds” on the Load Panels.

This is can be facilitated by removing the green bonding screw from the load panels and then Isolating all the neutrals (White Wires) to the neutral bar and then Isolating all the ground wires (Bare Copper Ground Wires) to the Isolated Ground Buss-Bar when this bonding screw is removed.

In most residential wiring systems in the USA, there is just a single service panel that acts as a combination Service Panel/Load Center. Residential Master electricians Bond The Neutral Bar to the Case which is earth grounded with this Green Screw. This configuration works fine for a single combination Service/Load panel as the Neutral and Ground wires are treated as the same. It simplifies wire hookup with Grounds and Neutrals.

Commercial Master Electricians know how to Float the Neutrals on their Load Centers by removing these Green Bonding Ground Screws. If the proper floating neutral isn’t performed concerning Load panels this will facilitate a feedback loop to the mains service panel which will heat up the Mains In Lines Buss-Bar wasting energy and possibly resulting in a Fire.

When utilizing emergency generators this practice of Floating The Neutrals and Isolating the earth ground is very important for the same reason.

Any misjudgment can be very dangerous.

Inverter failure caused by bonded neutral with the ground void the manufacturer’s warranty.

1 reply
  1. doug thompson
    doug thompson says:

    This page contradicts the following page

    https://www.sigineer.com/product-category/inverter-chargers/split-phase-inverter-chargers/

    where it says:
    Our split-phase inverters support wiring with neutral bonded with the ground or not.

    NEC code requires the neutral bonded with the ground.

    For other applications, neutral and ground separation preferred. Follow…. (this page)

    More precise information, and pages that agree is desired.

    Here is a link to my solar build thread where I want to upgrade from my 120v inverter to a 240v inverter.
    I have a 3 pole transfer switch for Hot1, Hot2, and Neutral between GRID AC for my critical loads panel and the inverter AC Output to the same loads panel.

    I am concerned about the Neutral to Ground Bond not being present when using the inverter output, in battery mode and grid bypass mode. When in bypass (grid supplying loads and battery charging) mode, the circuits of the critical loads panel (no N-G Bond) are NOT connected to the grid’s neutral (From Main service panel) at all. Only ground is common.

    my question is, in the above case, Inverter out Neutral to Ground Bond is NOT to be done? Even when not connected

    Reply

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.