Siemens 3VA1120-4EF32-0AE0 — SENTRON MCCB, Line Protection, 20 A
The Siemens SENTRON 3VA1120-4EF32-0AE0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection, rated at 20 A continuous current at 40 °C and carrying a 121 kA interrupting capacity at 240 VAC — enough to handle high-fault utility feeds without cascading upstream. Rated insulation voltage is 800 V, and the interrupting curve holds at 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V, so it covers 480Y/277 V and 600 V industrial services with headroom. The TM240 thermal-magnetic overcurrent release is fixed-trip, non-adjustable — set it and forget it for dedicated motor or feeder circuits where coordination studies have already locked the pickup.
Panel Fit and Mounting
At 76.2 mm wide, 130 mm tall, and 70 mm deep, this 3-pole MCCB fits standard Siemens 3VA panel footprints and mounts via the rear screw-clamp or optional DIN-rail adapter — verify gland-plate clearance for the 70 mm depth when the breaker sits behind a deadfront. Power loss is 12 W maximum at rated load, so the enclosure thermal rise stays manageable in a grouped panel; no forced ventilation required unless the ambient exceeds 40 °C. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C — fine for unheated warehouses and outdoor enclosures in temperate climates.
Auxiliary Switching and Accessories
This breaker ships with a factory-fitted HQ auxiliary switch block carrying 4 auxiliary contacts — no separate order needed for status feedback to a PLC or remote indication lamp. No undervoltage release, no shunt trip, no ground-fault monitoring, and no communication module are included; the base variant is a straight thermal-magnetic line protector. Add those as separate accessories if the spec requires remote trip or GFCI. The trip indicator is absent on this version — visual flag is not provided; if panel walk-by inspection needs a clear tripped/on state, specify the variant with the mechanical flag.