What this MCCB is and what it does
The Siemens 3VA2163-7MS36-0CL0 is a SENTRON molded case circuit breaker (MCCB) in the starter protection version — meaning it's built to sit ahead of a motor starter, combining short-circuit and overload protection in one 3-pole package. The 63 A rated continuous current (Iu) holds steady from 40 °C up to 50 °C, then derates gradually to 56.7 A at 70 °C, so you size it for the ambient inside the enclosure, not the panel room temperature. The ETU310M electronic trip unit handles the curve; no communication function or phase failure detection on this variant, just straight thermal-magnetic-style protection with an undervoltage release (UVR) integrated.
Interrupting capacity — what the numbers mean for your fault duty
The 330 kA at 240 V is the headline number, but the real-world duty is lower at distribution voltages: 242 kA at 415 V and 440 V, 187 kA at 500 V, and 52.5 kA at 690 V. That 52.5 kA at 690 V is still well above what most industrial MCCs see, so this breaker gives headroom for high-fault installations like transformer secondaries or large motor control centers. The 800 V rated insulation voltage (Ui) confirms it's rated for 690 V line-to-line systems without derating the dielectric.
Auxiliary contacts and trip alarm wiring
The auxiliary contact block is spec'd as 2 auxiliary switches + 1 trip alarm switch + 1 electrical alarm switch HQ — that's four discrete signal paths for remote status. The trip alarm switch closes on a fault trip, the electrical alarm switch signals when the UVR has operated. The base switch itself is order code 3VA2163-7MS36-0AA0; the integrated auxiliary trip module is 3VA9608-0BB24. If you're replacing just the trip unit or the aux block, those are the sub-component codes to cross.