MEASURING METHOD FOR INSULATION RESISTANCE OF CABLE OR ELECTRIC EQUIPMENT

• Main Authors: SHIRAHAMA OSAMU, UMEDA SUSUMU, YAMAMOTO MINORU, NIIMOTO TAKASHI
• Format: Patent
• Language: English
• Published: 27.07.1987
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

PURPOSE:To eliminate an influence of a noise current caused by a local battery, by applying a DC voltage between a cable shielding layer or a case of a power apparatus and a ground, and connecting an insulation resistance measuring resistance between a bus and a ground. CONSTITUTION:A voltage between a cable shielding layer 16 or case 44, and a ground is measured by applying a DC power source 52 between the cable shielding layer 16 or the case 44 of a power apparatus 40, and a ground. Also, a voltage across the resistance is measured by connecting an insulation resistance measuring resistance 74 between a bus 24 to which a cable, etc. have been connected, and ground. In this case, a current I0 flowing by the DC power source 52 flows through a series circuit of an insulator resistance 20 and the insulation resistance measuring resistance 74. Accordingly, by measuring a shared voltage of the insulation resistance measuring resistance 74, a shared voltage of the insulator resistance 20 is know, from which a value of the insulator resistance can be known.