What this module does in the panel
The Siemens 3VA9177-0TB10 is a COM060 communication module that snaps into the right switch pocket of a 3VA6 150/250 molded-case circuit breaker or a COM800 system. It draws 0.1 A max from the breaker's electronic trip unit supply, losing 2.4 W, and communicates switch position (On, Off, Tripped) plus data from the trip unit and residual-current equipment over a spur-line T-feeder interface. The 4-slot module supports up to 20 m total system length on the circuit-breaker communication bus.
Fit and environmental limits
Dimensions are 29 mm wide × 63 mm high × 33 mm deep — it lives inside the breaker pocket, not on the DIN rail, so it doesn't eat panel width. Rated IP20 (fingers, not water), pollution degree 3 (conductive or dry non-conductive pollution), overvoltage category I. Protection class III per IEC 61558 means it's supplied from a safety extra-low voltage source.