What this MCCB is and what the ratings mean for fit
The Siemens SENTRON 3VA2450-7MN32-0DH0 is a 3-pole molded case circuit breaker (MCCB) rated for a continuous current Iu of 500 A, with a motor protection version designation. The ETU350M electronic trip unit provides adjustable overload and short-circuit protection curves, plus phase failure detection. Breaking capacity is the headline number that determines whether this breaker clears a fault without welding its contacts or venting arc gas. At 240 V it interrupts 330 kA; at 415 V and 440 V it manages 242 kA; at 690 V it still holds 52.5 kA. Those figures are the ultimate short-circuit breaking capacity Icu — the breaker survives one fault at that level and must be replaced afterward. For a 500 A frame these are high values, meaning it can sit downstream of a large transformer or a high-capacity bus without needing a current-limiting fuse ahead of it. The auxiliary contact block is configured as 2 auxiliary switches plus 1 trip alarm switch (HQ version), which gives the PLC or SCADA a separate signal for a trip event versus a normal open/close. The undervoltage release (UVR) is built in — when line voltage drops below the dropout threshold the breaker opens, which is standard for motor circuits that must not auto-restart after a brownout.
Sourcing and lifecycle — current production, quoted to order
The SENTRON 3VA2 series is Siemens' mainline MCCB platform, so firmware and accessory compatibility (the ETU350M trip unit, the 3VA9608-0BB25 auxiliary trip, the 3VA2450-7MN32-0AA0 basic switch) are all current catalogue items.
Physical fit and panel integration
The breaker measures 248 mm high × 138 mm wide × 110 mm deep. It mounts on a DIN rail or directly to a backplate via the screw terminals. The IP40 rating on the front means it is protected against tools and wires >1 mm — standard for a closed panel; no special gasketing is needed for a dry indoor enclosure.
Compliance documentation
As a Siemens SENTRON product, the 3VA2450-7MN32-0DH0 carries CE marking for the European low-voltage directive.