PHASE SEQUENCE CHECKING APPARATUS

• Main Authors: KAWABE RIYOUICHI, SUGA MICHIO
• Format: Patent
• Language: English
• Published: 16.10.1982
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

PURPOSE:To achieve a safe and accurate checking without removing wire cables for load by informing of determination on whether the phase sequence is normal or not with respect to each detection voltage with the sequential application of a phase sequence checking DC current to a 3 phase AC power supply terminal varied in the level by phase. CONSTITUTION:With the operation of a phase sequence checking DC voltage application unit 5, phase sequence checking DC voltages VR, VS and VT are sent in varied level from a checking voltage application device at the times T1, T2 and T3 and applied to each of phases R, S and T at a power supply terminal of a first power board 1. With the application thereof, said voltages separately appear at an input terminal of a load 3 and are detected. The voltages thus detected are input into a discriminator 9 and compared with signals S from the checking voltage application circuit 7 to determine whether the phase sequence is normal or not. The result of the discrimination is displayed on an indicator.