It uses a TM220 thermal-magnetic overcurrent release — meaning the fixed thermal trip and magnetic short-circuit response are factory-set, no adjustment dial. Breaking capacity runs 75.6 kA at 240 V and drops to 52.5 kA at 415 V, so it handles high-fault utility feeds and transformer-secondaries.
Full 100 A rating holds through 50 °C ambient; at 55 °C it derates to 98 A, at 60 °C to 96 A, and at 70 °C to 91 A (–). If the panel runs warm — say a crowded enclosure near a drive — this breaker still delivers 91 A at 70 °C without nuisance tripping. The TM220 release won't drift with heat; the thermal element compensates across the curve.
Width 101.6 mm (4 in), depth 70 mm (2.76 in), height 130 mm (5.12 in). Front face carries IP40 protection. Insulation voltage rated 800 V.