[Question] 3 pole or 4 pole mcb for inverter input

[Tradie]

We all know that single phase inverters require a double pole isolator for the input and the output and the ATS must be a double pole.

The question, regarding 3 phase inverters input/output output:

We now know that a Sunsynk inverter doesn't have an ATS, but rather a common busbar system which drops out the grid supply, (islanding mode).

Some inverters dont have a built in method for islanding mode, but rather a box on the wall, referred to as a gateway, which should have ATS.

The ATS or islanding mode contactor 3 pole or 4 pole?

The inverter input isolator/mcb must be 3 or 4 pole?

The inverter output isolator/mcb must be 3 or 4 pole?





The input isolator/circuit breaker feeding the inverter - 3 pole or 4 pole?

The output

[Tradie]

NRS 097-2-1-2017 goes into detail on page 36 and 37, depending on the type of earthing.

The new NRS-097-2-3 2023 has no mention of how many poles and NRS-097-2-1 2024 also has no reference.

It is very important to understand your method of earthing, otherwise you could end up following some advice shared on social media or groups that could make your installation non compliant.