What it is and what the ratings mean
The Siemens 3VA2440-7HN32-0AH0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection in three-phase distribution. The 4800 A frame size is the mechanical envelope that carries the interrupting mechanism — the continuous current rating is 400 A across the full ambient range from 40 °C to 70 °C, meaning no derating is needed for a warm panel environment up to that ceiling. The 330 kA breaking capacity at 240 V and 242 kA at 415 V means this breaker can safely interrupt a fault of that magnitude without welding contacts or cascading failure upstream — critical for high-fault installations like transformer secondaries or large motor control centers. At 690 V the breaking capacity drops to 9 kA, so verify the available fault current at that voltage before specifying.
Integration and panel fit
The 3VA2440-7HN32-0AH0 measures 248 mm high by 138 mm wide by 110 mm deep. That 110 mm depth is the dimension from the mounting surface to the front of the breaker — critical when the panel door clearance is tight. The width of 138 mm means it occupies three pole spaces on a standard DIN-rail or bolted bus system; verify the bus bar spacing matches the 3-pole footprint before cutting the backplate. The auxiliary switch configuration (2 auxiliary switches + 1 trip alarm switch) is built in, so no separate add-on block is needed for status feedback to the PLC or alarm annunciator.
Short-time withstand and trip indication
The breaker is rated for a short-time withstand current of 5 kA limited to 1 second — this is the current the breaker can carry without damage during a delayed trip coordination scheme, typical in selective coordination where the downstream breaker clears first. The trip indicator is present, so a visual flag confirms the breaker has opened on a fault rather than being manually switched off — saves a troubleshooting trip to the panel.