Is my SMA inverter 3 phase or single phase? Finn Peacock November 09, 2017 02:22 Updated Follow If your SMA inverter is red it is single phase. If your SMA inverter is blue, it is 3 phase. Related articles How do I install micro inverters on a 3 phase supply? I've been told my existing solar system / inverter is not compliant with the current standards. What do I have to do? I have 3 phase power. Should I use a 3 phase inverter or a single phase inverter? What inverter brands do you trust? I want to mount my panels a long way from the switchboard - how thick should the cable to the switchboard be to minimise voltage drop? Comments 0 comments Please sign in to leave a comment.