Do you need all the "stuff" when installing a 3 kva inverter. I see on most small inverters, people just plug and play. I had a look at an installation in a commercial building 3 KVA axpert type. the batteries are just place directly on the floor, no combo breakers, isolators, changeover switch, no surge protection, nothing. The unit is mounted to the wall and a piece of trunking straight into the 3 phase DB. Fed from a single pole breaker and back onto a busbar at the top of the light circuit breakers.


I have never installed a 3 KVA unit, only 5 and up. We normally go the whole hog with components:

D/P combo breakers from the mains.
D/P combo breaker for the inverter output.
changeover switch.
Surge protection.
Fuses on the batteries (24 VDC - 2 X 100 amp/hr)
Maybe even earth leakage protection if it is not feeding dedicated blue socket outlets for essential items like, computers, alarms systems CCTV etc.