Digital Overspeed Switch

             

The digital overspeed switch from Wildfire continuously monitors engine speed through the use of a microcomputer. Once an overspeed condition is detected, the microcomputer confirms it exists and shuts down the pump. The DOS unit does not require the use of batteries; it powers up once the engine is operating. The DOS is installed with a single wire on the side of the fan cowl above the carburetor shroud. Available exclusively for the Mark-3 fire pump with electronic ignition module (purchased after November 2003), the DOS is now a standard feature with the exception of the GSA version.