Single-action, manual fire-alarm boxes by Siemens Industry, Inc. ─ Fire Safety (Models MS-51 and MS-501) have been designed with extreme flexibility, in order to meet an array of system application requirements and operation sequences.

The aforementioned models operate in a single-action mode, which utilizes a ‘pull-down’-lever action. The cover for each fire-alarm box locks in the ‘down’ position, until the box is reset.

The single-action box, which shall be of the non-code type, shall consist of a molded housing fitted with a ‘pull-down’ lever, which ─ when operated ─ locks in position after releasing a spring-loaded contact switch to activate the alarm circuit.

Models MS-51 and MS-501 contain one (1) normally open contact (NC), which is intended for use with Siemens ─ Fire Safety low-voltage systems. These two (2) manual boxes can also be used for connection to existing fire-alarm systems of other manufacturers.