When connecting multiple inverters in parallel, where should the output neutrals be grounded?

Grounding the output neutrals of multiple inverters at the main AC grounding/neutral bus is essential for several reasons related to safety, regulatory compliance, and system performance.

First, grounding at the main AC grounding/neutral bus ensures that the neutral is properly referenced to ground throughout the entire electrical system. This helps to prevent voltage imbalances that could occur between the neutrals of the individual inverters, ensuring all connected equipment operates within safe voltage limits.

Second, this approach provides a common grounding point for all inverters, simplifying the overall grounding scheme. It mitigates the risk of potential ground loops that could arise if neutrals were grounded at different points in the system. Ground loops can introduce noise and instability, affecting the performance and reliability of the inverters.

Lastly, grounding at the main panel aligns with the National Electrical Code (NEC) requirements, which dictate that the grounding conductor for the entire electrical system should be connected at a single, defined point to prevent issues related to overvoltage, electrical shock, and fire hazards.

In contrast, grounding at the inverter or at the battery bank could lead to questions of stability and compliance with electrical codes, while grounding at the service panel generally pertains to the overall system grounding and bonding practices rather than