Title:
NORMALLY MONITORING SYSTEM FOR VACUUM BREAKER
Document Type and Number:
Japanese Patent JPH01301136
Kind Code:
A
Abstract:
PURPOSE:To reduce a cost, to make compact and to improve a reliability by making three phases of detectors en bloc, providing an input part to make plural detectors en bloc and monitoring plural vacuum breakers en bloc. CONSTITUTION:When a degree of the vacuum is reduced, an electric discharge is made to start between a lead and a shield in a vacuum valve 1 according to a Persian curve, and along with this discharge, a current in a pulse state is made to flow through the shield and an electrostatic capacity of a detecting electrode 2. This current is taken out with an input impedance of the detector 3 as the voltage, and the vacuum quality is decided by the current level, produced time and number. Then, these currents are mutually made to cancel by means of composing the currents of a commercial frequency in such a manner that three phases of the detectors 3 are made en bloc, and the discharge currents only in the vacuum valve 1 is defective are detected. Further, the plural vacuum breakers are monitored en bloc by providing the input part to lump together the plural detectors 3, then, the plural pairs of the input part and a display part are connected freely changeable to one detecting circuit, thereby the monitoring is performed.
Inventors:
SAKAKI MASAYUKI
Application Number:
JP13233588A
Publication Date:
December 05, 1989
Filing Date:
May 30, 1988
Export Citation:
Assignee:
MEIDENSHA ELECTRIC MFG CO LTD
International Classes:
G01L21/30; H01H33/66; (IPC1-7): G01L21/30
Attorney, Agent or Firm:
Fujiya Shiga