The Siemens 3VA2140-7MQ32-0DH0 is a 3-pole IEC frame 160 circuit breaker with a 40 A rated current and a breaking capacity class C rating of 110 kA at 415 V. This is the interrupting capacity that governs fault clearing on a 400 V distribution bus — at this level it handles high-fault scenarios without cascading upstream, which matters for selectivity coordination in a motor control center.
Protection and release
Fitted with an ETU860M electronic trip unit providing LSIG protection: long-time (Ir) adjustable 16–40 A, short-time (Isd) 1.2–15x In, instantaneous (Ii) 3–15x In, and ground-fault (Ig) 0.4–1x In with adjustable time delay tg 0.05–0.8 s. The LSIG suite means this breaker covers overload, short-circuit, and ground-fault in one package — typical for a motor feeder where you need coordinated protection against both phase and ground faults without a separate relay.
Accessories and auxiliary wiring
Includes an undervoltage release (UVR) rated 208–230 V AC 50/60 Hz, two auxiliary switches (HQ), and one trip alarm switch (HQ). The UVR drops the breaker on loss of control voltage — standard for safety circuits where a downstream contactor also needs to drop. Auxiliary switches and the alarm contact give the PLC a status read without tapping the load terminals.