The Marsh Bellofram SPM series is a dual function alarm and relay, designed to monitor shaft seal and stator temperature of a submersible pump motor, providing early warning of machinery failure to reduce downtime and maintenance costs. It is designed to operate from a 120 VAC supply voltage, with reliable operation over 10 million continuous duty cycles. The series detects leaks by either resistive float switch or a pair of conductive probes installed in the seal cavity, while over-temperature is detected by a normally-closed low-temperature switch that is mounted on the stator, with LEDs that indicate green for “normal” and red for “leak” and “over temperature” condition values. The SPM series also incorporates the use of a bi-stable relay which can retain its position during power failures or energy surges. The relay automatically resets following leakage detection. Sensor voltage is 12 VDC at 50 to 60 Hz. Units are UL listed and include a 10-year comprehensive product warranty.