Its TM220 thermal-magnetic release holds 40 A continuously at 40 °C and derates to 37 A at 70 °C. The interrupting ratings are the headline: 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at both 500 V and 690 V — that 187 kA figure at 240 V is the high-fault capability a panel designer needs when the available fault current on a transformer secondary is over 100 kA.
Rated current is flat at 40 A from 40 °C through 50 °C, then drops to 39 A at 55 °C and 60 °C, 38 A at 65 °C, and 37 A at 70 °C. Maximum power loss is 10.8 W — relevant for heat buildup in a densely packed enclosure.
Dimensions: 130 mm height, 76.2 mm width (3 in), 70 mm depth (2.76 in). Three poles on a standard MCCB footprint.
Release design and DC capability
The overcurrent release is designated TM220 — a thermal-magnetic type without electronic trip adjustment.