What this MCCB is and what it does
The Siemens 3VA2163-7MS36-0DH0 is a SENTRON molded case circuit breaker (MCCB) in a starter protection variant — meaning it's built for motor branch circuits where you need coordinated overload and short-circuit protection in one device. It carries a rated continuous current Iu of 63 A and a rated insulation voltage Ui of 800 V, so it's sized for typical 400 VAC motor feeders up to roughly 30 kW. Three poles, no communication module, no ground-fault monitoring — this is a straightforward electromechanical breaker with an ETU310M electronic trip unit. The interrupting ratings climb to 330 kA at 240 V and 242 kA at 415 V, which puts it in the high-fault-current category for distribution panels where upstream transformer capacity is large.
Interrupting capacity — what those numbers mean for your panel
The 330 kA at 240 V and 242 kA at 415 V are the maximum short-circuit currents this breaker can safely interrupt without welding contacts or rupturing the case. If your available fault current at the panelboard exceeds these values, you need a current-limiting upstream device or a higher-rated frame. At 690 V the rating drops to 52.5 kA — still substantial, but the voltage derating is real. The ETU310M trip unit provides LI (long-time and instantaneous) protection curves, settable via rotary dials on the front. It's not a full selective-coordination trip (no short-time delay), so this breaker is best applied as a main or feeder breaker where instantaneous trip coordination with downstream devices is acceptable.
Panel fit — dimensions and auxiliaries
Footprint is 105 mm wide by 181 mm high by 86 mm deep — a standard 3VA2 frame size that drops into existing SENTRON panel cutouts without modification. The breaker ships with an undervoltage release (UVR) fitted, plus a 2+1 auxiliary contact block (2 auxiliary switches + 1 trip alarm switch HQ). If your BOM specifies a different auxiliary configuration, the 3VA9608-0BB25 trip alarm can be swapped out.