What this MCCB does — and what the ratings actually mean for your panel
The Siemens SENTRON 3VM1120-4ED12-0AA0 is a 1-pole molded case circuit breaker (MCCB) rated for line protection. Its 20 A continuous rating holds across 40 °C to 55 °C without derating — only at 60 °C does it step down to 19 A, so for most panel environments you get the full 20 A. The interrupting capacity tells the real story: 76 kA at 240 VAC means it can clear a massive fault on a 240 V distribution bus, but drops to 9 kA at 415 VAC — that's still enough for most 415 V feeder applications, but if your available fault current at the panel exceeds 9 kA at 415 V, this breaker won't coordinate. The TM210 release is a fixed thermal-magnetic trip: thermal pickup at 20 A (non-adjustable), magnetic instantaneous trip fixed at 320 A. No ground-fault monitoring, no communication module, no motor drive — this is a straight-ahead line-protection MCCB for basic branch circuits.
DIN-rail fit and panel integration
At 25.4 mm wide (one inch), this single-pole MCCB snaps onto standard DIN rail. Depth of 70 mm and height of 130 mm — check gland-plate clearance if you're back-panel mounting. Front-face protection is IP40, so it's fine for dry indoor panels but not washdown zones. The 500 V rated insulation voltage (Ui) covers most 400 V line-to-line systems with headroom.