The ISS-105 is a “smart” five-channel intrinsically safe relay and pump controller. The ISS-105 can be configured for a wide variety of applications including alternating or non-alternating duplex, duplex separate pump stop (SPS), triplex and quadplex applications. It can be set up for pump-up or pump-down applications or can be used as a five-channel relay. The ISS-105 has a long list of features that are needed for multiple pump applications. The ISS-105 can indicate low, high and out-of-sequence alarms. If an out-of-sequence alarm occurs, the skipped pump(s) will be started as intended. The Model ISS-105 can be set up to do non-alternating control, alternating control and alternating control with one non-alternating pump. The non-alternating pump is intended for use with an emergency or jockey pump. The ISS-105 can start an emergency pump once every 50 cycles to keep it working freely. Using the built-in DIP switches, individual pumps can be disabled when taken out of service for repair or maintenance.