Bases 13-20 for three-phase watt-hour meter

IT IS USED TO RECEIVE WATTMETER FROM C.F.E. IN THREE-PHASE, COMMERCIAL AND INDUSTRIAL SERVICES, WHERE CONSUMPTION EXCEEDS 200 A. THEREFORE IT IS NECESSARY TO MEASURE THROUGH CT’S ON THE LOW VOLTAGE SIDE OR BY USING CT’S AND TP’S ON THE HIGH VOLTAGE SIDE OF THE TRANSFORMER, FOR OUTDOOR USE (NEMA 3R).