PURPOSE: To easily attach a current detector to a cable and to obtain an accurate measured value by setting a magnetic body to an annular shape with a protective cover and mounting an optical magnetic field sensor between upper cover members on both sides.
CONSTITUTION: A magnetic core 11 is arranged around a three-phase cable 2 and constituted as an annular member having a gap at the upper part thereof and a protective cover 15 is provided to the periphery of the magnetic core 11. The cover 15 is constituted of the base cover member 6 integrally molded to the core base part 12 constituting the lower semicircular part of the core 11 and the sheath-shaped upper cover members 17, 17a arranged on both sides of the member 16. A gap is formed between the other end parts of these members 17, 17a and a sensor holder 20 is provided to said gap and a sensor 25 is provided to the sensor inserting hole 21 provided to the holder 20. Since the gap is positioned only at the part of the sensor in this magnetic core thus constituted, the value of the current flowing to the cable can be accurately obtained.
SAKAI SEIICHIRO
SAKAMOTO ATARU
TAKAHASHI MASUKIYO
MITSUBISHI CABLE IND LTD