Is my SMA inverter 3 phase or single phase? Finn Peacock March 20, 2018 06:50 Updated Follow If your SMA inverter is red it is single phase. If your SMA inverter is blue, it is 3 phase. Related articles I have 3 phase power. Should I use a 3 phase inverter or a single phase inverter? How do I install micro inverters on a 3 phase supply? What inverter brands do you trust? I've been told my existing solar system / inverter is not compliant with the current standards. What do I have to do? How does a single phase inverter on a 3 phase supply affect my self consumption? Comments 0 comments Please sign in to leave a comment.