Its TM120M thermal-magnetic overcurrent release provides inverse-time overload protection plus instantaneous short-circuit trip, sized for a 20 A continuous load at 40 °C through 55 °C; at 60 °C it derates to 19 A, holding to 19 A through 70 °C. The headline breaking capacity is 220 kA at 240 VAC, dropping to 154 kA at 415 VAC, 121 kA at 440 VAC, and 7.5 kA at both 500 VAC and 690 VAC — so at higher line voltages the interrupting capability falls sharply, and the 7.5 kA figure at 500/690 V is the one that governs coordination in a 480/600 V panel.
Where it is used and how it mounts
This MCCB is intended for panel or enclosure mounting in motor control centers, starter assemblies, and industrial control panels where the breaker protects a motor starter branch. It occupies a 76.2 mm wide by 130 mm tall by 70 mm deep footprint (3 in × 5.12 in × 2.76 in). The design is for fixed mounting — not a plug-in base — so panel cutouts and bus connections must be planned for this specific frame size.