a periodic tester to determine the readiness of a fire pump system interfaces with a fire pump controller , an electric motor , and a sprinkler system . the fire pump controller has a power on / off sensor which interfaces with an electric motor which starts the fire pump to provide water to the sprinkler system . the power on / off system has a contactor coil as a component . the periodic tester targets two of the main components of fire system failure : the power on / off sensor and the contactor coil . the periodic tester may be retrofitted to existing systems and interface either directly or indirectly with the power on / off sensor to accommodate both systems that have a solenoid valve and those that do not . the periodic tester is designed to attempt to start the system only once during a set cycle . any failure to start is displayed through audible and visual alarms .