Hi Everyone

I have a small solar system driving some essential loads (TV, internet fridges) and my pool pump and heat pump. My inverter is plugged into a normal 20amp 3 pin plug point. Inverter is set to SUB priority, and my heat pump and pool pump are on timers to optimize running off solar. Batteries are only for backup during loadshedding, and not being used at night. System details:

1. Inverter - Sun (Conderenergy) S-2542

2. Panels - 6 x Jinko 555W in series

3. Batteries - 2 x Hubble S100 in Series 

Recently, my inverter has been tripping the main earth leakage. I have 2 x output DBs on the main and essential outs of the inverter, both of which have earth leakage and 10 amp CB's. I would like to run a separate input to my inverter in parallel to the house DB, effectively splitting before that board. My current plan is to install a small DB fed from the Eskom input, with a Main switch (two pole), earth leakage and 30 amp breaker, feeding a 4mm line to the inverter input - effectively allowing the inverter to trip independently from the house. 

My question is whether it is normal for the inverter to trip the earth leakage? It was running quite happily for around 6 months, and is now consistently tripping after being on grid for about 5 mins. I have tested with the inverter only powered from the db, and it still trips is this normal, or is the inverter faulty?

There is a "bonding relay" inside of the most inverters. Once the inverter becomes the source of energy, relay is closed. Therefore the main RCD/RCBO will trip. 

Some inverters have this configurable, some fixed. (Dont know how yours have this, sorry.)

Feeding the inverter directly is a sure fix.

BTW: In my country, a separate RCBO is required for every set of circuits and has to be installed after the inverter. There must be just a MCB before the inverter. Lights must have a dedicated RCBO per each light circuit.