UL Certification. LPRT/2 Phase Failure, Phase Sequence, Under Voltage plus Time Delay. Broyce Controls L-Series signal conditioners use a QR barcode marking method allowing direct access to all technical data sheets, ensuring correct information is always at your finger tips!. Features and Benefits. Compact 17.5 mm DIN Rail housing. Microprocessor based. True R.M.S. monitoring measuring phase to phase (three wire) or phase to neutral (4-wire) voltages. Selectable nominal voltages to suit most popular three wire or 4-wire supply voltages. Monitors own supply and detects an Under voltage condition on one or more phases. Detects incorrect phase sequence, phase loss and neutral loss1. Adjustment for Under voltage trip level. Adjustment for time delay. DPDT relay output 5A. Green LED indication for supply status. Red LED indication for relay status