The Siemens B120 is a one-pole molded case circuit breaker rated 20 A at 120 VAC with a 10 kA interrupting capacity. It installs in compatible Siemens load centers and panelboards to protect branch circuits from overloads and short circuits. The breaker is also listed for operation at 400 Hz, making it suitable for certain aircraft, marine, or specialized industrial power systems that require this frequency rating.
