The ABB 1SDA055172R1 is a SACE Tmax T2 moulded case circuit breaker, 3-pole, rated 100 A continuous. It carries a 70 kA ultimate short-circuit breaking capacity at 500 V DC with all three poles in series — that is the number that governs DC fault clearing on battery banks, UPS feeds, or solar combiner outputs. UL 489 listing means it is accepted for branch-circuit protection in North American panels without additional fusing.
The 500 V DC rating with 70 kA Icu is the headline for DC applications. Unlike AC where zero-crossing aids arc extinction, DC breakers must stretch and cool the arc without a natural current zero — the three poles in series share the arc voltage, which is why ABB specifies the 3-pole-in-series configuration for that 70 kA figure. If your DC bus is lower voltage (250 V, 125 V), the breaker still works, but the interrupting capacity may be higher than stated; coordination studies should use the published 500 V DC value as the conservative bound.
AC ratings and panel integration
Electrical durability is 8,000 cycles under load; mechanical endurance 25,000 cycles. For frequent switching applications (e.g., capacitor bank or motor feeder with daily cycles), the electrical life may be the limiting factor — plan spares accordingly.