The Siemens 3RV1936-2B is a door-coupling rotary operating mechanism from the SIRIUS family, designed for heavy-duty operating conditions on circuit-breakers of size S2. It mounts via screw fixing in any position and is rated for up to 151 operations per hour, with an operating temperature range of -20 to +70 °C. The mechanism is intended for panel-mounted circuit breakers where the operator needs to open or close the breaker from outside the enclosure door — common in motor control centers and distribution panels.
This part is in product phase-out. The manufacturer lists the successor as 3RV2936-2B, which carries a different drilling pattern — so a panel cutout or mounting plate change may be required when switching.
The mechanism measures 78 mm depth, 75 mm width, 75 mm height, with a total length of 300 mm. The handle is gray. Screw fixing allows secure attachment to the enclosure door. The mechanism couples to the breaker rotary operator through the door, so the door thickness and alignment must be checked against the 78 mm depth dimension.