Siemens MS-51


Manual Station N.O. SPST

Availability: Estimated 6 - 8 Business Days

  • Factory New
Brand: Siemens Part #: 51765 Categories: , , Manufacturer Part #: MS-51Secondary Part #: 500-620503


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.


Weight 0.50 lbs









  • Durable plastic design
  • Shock and vibration resistant
  • Activation visibly noticeable
  • Optional contact arrangements
  • No break rods necessary
  • Surface or semi-flush installation
  • Options include key switch or alarm lamp
  • Meets ADA guidelines
  • UL Listed; FM, CSFM & NYCFD Approved


‘MS’ Series ─ Single-Action, Manual Fire-Alarm Boxes; Models MS-51, MS-501
Siemens – Data Sheet – 2012

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