Siemens SENTRON 3VA1120-3EF32-0DC0 — 20 A MCCB with UVR and 2 Aux Switches
The Siemens SENTRON 3VA1120-3EF32-0DC0 is a 3-pole molded case circuit breaker rated for a continuous current of 20 A at 40 °C, with a TM240 thermal-magnetic overcurrent release. Its breaking capacity reaches 75.6 kA at 240 V AC, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V — covering most industrial distribution panels up to 690 V line voltage. The unit ships with an integrated undervoltage release (UVR) and two HQ auxiliary switches, so it can signal breaker status to a PLC or safety circuit without an add-on module. At 70 mm deep, 76.2 mm wide, and 130 mm tall, this MCCB fits standard Siemens SENTRON panel footprints and mounts via the rear clip or screw terminals. Front IP40 protection means it is suited for enclosed distribution boards where dust ingress is limited.
Breaking Capacity and Selectivity — What the Ratings Mean
The 75.6 kA at 240 V is the maximum fault current the breaker can safely interrupt at that voltage. At 415 V the rating drops to 52.5 kA, and at 690 V to 10.5 kA — this is typical for a 20 A frame; it means the breaker can be used in high-fault-capacity 240 V panels (e.g., near a large transformer) but needs upstream coordination at higher voltages. The TM240 release provides thermal protection for overloads and magnetic trip for short circuits, with the magnetic threshold fixed at 240 A (12x In).
Integration — Panel Fit and Wiring
The 3VA1120-3EF32-0DC0 drops into a standard SENTRON MCCB cutout. The two HQ auxiliary switches (form C) can be wired to a PLC digital input for remote status; the undervoltage release (UVR) requires a separate 24 V DC or AC supply (coil voltage not listed here — verify against the panel control voltage). The TM240 release is non-interchangeable, so the breaker is factory-set for 20 A continuous.