The ABB 2CDS272001R0034 S202M-C3 is a 2-pole miniature circuit breaker from the System Pro M Compact S200M family, rated 3 A with a Curve C trip characteristic.
Curve C trips between 5 and 10 times rated current, so the 3 A rating means magnetic trip occurs between 15 A and 30 A — typical for lighting, socket outlets, and small motor loads with moderate inrush. The 125 V DC rating per pole covers common DC control circuits and battery-backed loads, but note that DC breaking is polarity-sensitive on most MCBs — confirm the manufacturer's wiring diagram for the DC side.