What this breaker does in a solar combiner or distribution panel
The TM-D trip unit has thermal memory, so it retains heat history after a trip and will re-trip faster on a repeated overload, which matters for solar strings where intermittent cloud cover can cause repeated current surges. The 25 kA at 800 V AC is the interrupting rating for the solar-typical voltage; at lower voltages the rating may be higher, but 800 V is the operational voltage listed. The 40 W power dissipation per pole means 120 W total at full load — plan for ventilation in the enclosure if multiple breakers are ganged.
Accepts horizontal or vertical orientation. The 120 mm width, 205 mm height, and 105 mm depth fit standard enclosure backplate layouts; the 40 mm pole pitch aligns with common busbar systems. IP20 provides finger-safe terminal protection but the breaker must be inside a weatherproof enclosure for outdoor use.