MCCB for line protection — 160 A frame, TM220 release
The 160 A rating holds flat from 40 °C through 50 °C, then derates to 158 A at 55 °C, 155 A at 60 °C, 153 A at 65 °C, and 150 A at 70 °C, so for a panel running warm (say 50–55 °C ambient) you still get full 160 A; above that the derating is modest and predictable. Breaking capacity is rated per the system voltage: 121 kA at 240 V, 76 kA at 415 V, 53 kA at 440 V, and 12 kA at 500 V. That 76 kA at 415 V is typical for a 160 A frame in industrial distribution — sufficient for most secondary-side transformer feeds and large motor branch circuits. The insulation voltage is rated 800 V, so the breaker can be applied in 480/277 V or 400/230 V systems with headroom. The TM220 release designation means the thermal fixed pickup is at 220% of the rated current (352 A for this 160 A frame), and the magnetic instantaneous trip is fixed — no field-adjustable dials. This is a fixed-release MCCB, suited for applications where coordination studies have already set the trip points and you don't need field tweaking.
The breaker measures 130 mm high, 76.2 mm wide, and 70 mm deep — a standard 3-pole MCCB footprint for a 160 A frame. Maximum power loss is 38 W at rated load, which factors into enclosure thermal calculations.