MCCB for line protection — 160 A frame, TM220 release
The Siemens SENTRON 3VM1116-4EE32-0AA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a 160 A continuous rating at 40 °C ambient, with a TM220 thermal-magnetic release — the thermal element handles overloads, the magnetic element clears short-circuits. 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. No undervoltage release, no shunt trip, no ground-fault monitoring on this variant.
Panel fit and mounting
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. Front protection is IP40, meaning tools or fingers won't accidentally contact live parts from the front, but the breaker is not sealed against water ingress; it belongs in an enclosed panel. Maximum power loss is 38 W at rated load, which factors into enclosure thermal calculations.