Motor control relays (starting at $24.00) perform specific protective functions for motors or motor components to ensure proper and efficient operation. Phase monitor relays can detect faults in a 3-phase system and provide protection against phase loss, phase reversal, phase unbalance, under voltage and overvoltage. Alternating relays are used in special applications where the optimization of load usage is required by equalizing the run time of two loads. Pump seal failure relays monitor submersible pump shaft seals; the relay output can be used to give an alarm indication of a leaking seal. The relay automatically resets when the fault condition clears. Intrinsically safe relays (from $75.00) allow control of up to four loads with corresponding discrete input devices (switches, sensors) located in hazardous areas. The onboard SPST relays operate at either AC or DC coil voltage ratings.