What this breaker carries
The Siemens 3VA1150-5EF32-0CA0 is a 3VA1 IEC frame 160 molded case circuit breaker with a 55 kA interrupting capacity at 415 V (breaking capacity class M). That Icu rating means it can safely clear a fault up to 55,000 A without welding its contacts or rupturing the enclosure — enough headroom for most industrial distribution panels fed by a medium-voltage transformer. It's a 3-pole unit with a TM240 thermal-magnetic trip unit. The thermal overload is adjustable from 35 A to 50 A (In=50 A), and the magnetic short-circuit pickup is set at 5 to 10 times In — so 250 A to 500 A instantaneous. That's a standard motor-circuit range; the lower end protects branch feeders, the upper end rides through motor inrush. This variant ships with an undervoltage release (UVR) rated 120-127 V AC, 50/60 Hz, plus a nut keeper kit for the terminals. The UVR drops the breaker open when control voltage falls below its dropout threshold — typical for emergency-stop chains or undervoltage protection on machine feeds.
Lifecycle and sourcing
For a BOM line that needs this exact order code, the supply posture is straightforward: quoted and sourced to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time.
What the ratings mean for fit
The 55 kA Icu at 415 V puts this in breaking capacity class M — the middle tier in Siemens' 3VA1 lineup. It coordinates downstream with standard panelboard breakers and upstream with a transformer secondary rated for similar fault current. If your available fault current at the breaker's line terminals exceeds 55 kA, step up to class H (higher Icu). The TM240 trip unit is thermal-magnetic, not electronic. That means no external power needed for the trip function, but also no adjustable time-delay curves or ground-fault protection. For simple motor or feeder protection where selectivity is managed by current magnitude rather than time bands, this is a clean fit. The UVR coil draws from a 120-127 V AC control circuit. Verify your control transformer taps — a 120 V nominal supply is fine, but if your panel runs 110 V or 130 V, check the dropout and pickup thresholds in the Siemens application manual. The nut keeper kit is a small thing but saves time on the panel build: it prevents the terminal nuts from backing off under vibration.