The Siemens 3VM9908-0BB24 is an undervoltage release accessory designed for the 3VM10 through 3VM14 molded-case circuit breaker frames. It trips the breaker when the control voltage drops below its dropout threshold, protecting downstream loads from undervoltage conditions or providing a remote shunt-trip function on loss of control power. The release coil is rated for 120-127 V AC at 50/60 Hz — a standard control voltage in North American and 50 Hz industrial panels. This is a line-voltage accessory, not a 24 V DC electronic release; verify the control circuit matches before specifying.
Lifecycle status is active per the manufacturer's current product status flag. The part remains in the Siemens ordering catalog with no announced end-of-life or last-time-buy window. RoHS compliance is confirmed effective 01-10-14, and the REACH candidate list includes lead (CAS-No. 7439-92-1) above the 0.1% threshold — a standard disclosure for electrical components with solder or contact materials. Product class B means return-restricted; coordinate with your Siemens channel partner before initiating a return. The packaging dimensions are 124 x 90 x 41 mm, single-piece quantity unit.
Mounts inside the 3VM10/3VM14 breaker accessory slot — no additional DIN-rail space required. The release mechanically interfaces with the breaker's trip mechanism; wiring is to the coil terminals only, with no auxiliary contacts integrated into this accessory. Verify the breaker frame has the accessory slot populated and the correct voltage tap available in the panel.