The Series 1501 instrument is a microprocessorbased alarm, shutdown and control system with tachometer/hourmeter function. It annunciates in alphanumeric characters the protective device that has signaled an alarm or caused equipment shutdown. Information is called up and adjustments are made on a six-button keypad on the face of the unit. Configurations such as: Alarm or Shutdown Nomenclature, Preset Timers, and Tachometer Calibration can be made in the field. Murphy’s Series 1501 system has seven SPDT relays. On the standard model, the relays are assigned to the following functions: Lube, Crank, Ignition/Motor, Fuel Valve, Load, Alarm, Shutdown. The complete Series 1501 system consists of a head (monitor), sensor input terminal strip (two needed for 64 sensor models), 36 inch (914 mm) flat ribbon cable(s) for connecting the terminal block to the head/monitor, and a Class I, Div. 1, explosion-proof power supply. The Series 1501 system is powered from 120 VAC or 12 or 24 VDC. The head/monitor is rated intrinsically safe and includes a communication port: RS232 or RS485 (Modbus RTU slave). This port allows for remote control functions such as Start/Stop, Load/Unload, etc., and for access to Series 1501 registers.