Obsolete 05/26/2016. The PGR-6800 Pump Protection Relay provides protection for pumps with three-phase motors up to 1,000 Vac. No current transformers are required for currents up to 91 A. The protective functions include overload, phase unbalance, phase loss, phase sequence and undercurrent. The PGR-6800 Pump Protection Relay is ideally suited for applications where operating without load can induce failure. Motor current is monitored and an undercurrent trip occurs when the current drops below a preset level. No additional level detectors are required.