The Siemens 8UD1900-2DA00 is a shaft-coupling adapter built for use with 3VA series door-coupling rotary mechanisms. It accommodates a shaft size of 88 mm, allowing seamless mechanical linkage between a rotary operator and a molded-case circuit breaker.

This compact adapter is very light and small – dimensions are roughly 14.5 mm height, 12 mm width, and 28 mm depth – making it ideal for installations where space is limited. It adds flexibility to mounting and enables door-mount operation of breakers without modifying the core mechanism.

Made from robust materials, the adapter ensures reliable, vibration-resistant coupling even under heavy use. It provides a precise mechanical interface that extends the reach of control shafts while preserving safe and durable operation of 3VA breakers.

Whether used in wall-mounted switchboards, industrial panels, or enclosure-mounted breaker setups, the 8UD1900-2DA00 offers a neat, professional solution for external control through doors or access panels.