The SENTRON 3VM1120-3EE46-0AA2 is a 4-pole molded case circuit breaker (MCCB) rated for 20 A continuous current across the 40 °C to 55 °C ambient range, with only a 1 A derating step at 60 °C. That thermal stability means it holds its full rating in a warm enclosure without oversizing the frame — useful when the panel sits near a motor or drive. The interrupting capacity tells the real story for fault coordination: 76 kA at 240 V AC, 53 kA at 415 V AC, 32 kA at 440 V AC, and 11.9 kA at 500 V AC. The N switching capacity class means this breaker is designed for normal-duty industrial distribution — not the high-stress utility tie or large motor branch that demands the S class. For most panelboard and sub-distribution applications, the N class provides the right balance of fault-clearing muscle without paying for a frame you don't need. The TM220 overcurrent release is a thermal-magnetic type — thermal element for overload protection, magnetic trip for short-circuit. The LI protective function confirms it provides long-time delay and instantaneous protection, no electronic adjustment. That makes it a straightforward drop-in for standard feeder or branch protection where you don't need the selectivity tuning of an electronic trip unit.
The main current circuit uses box terminals with front connection — standard for panelboard and switchboard mounting. The frame size is rated for up to 160 A, so this 20 A breaker sits in a physically larger frame than its continuous rating suggests. That's typical for the 3VM platform: the frame is sized for the interrupting capacity, not the amp rating. Verify the mounting footprint against your existing bus bar or DIN-rail adapter before committing the panel layout. Front IP40 protection. No motor drive option and no auxiliary contacts from the factory.
Environmental limits and power loss
Maximum power loss 12 W.