Title:
PROTECTIVE RELAY
Document Type and Number:
Japanese Patent JP3280693
Kind Code:
B2
Abstract:
PURPOSE: To provide a protective relay capable of detecting service interruption with high reliability at high speed while being also able to detect a fault at an apogee.
CONSTITUTION: A first detecting means 10 outputting a first detecting output when both power-supply frequency and power-supply voltage reach each set value (49.5Hz and 95V) or less and a second detecting means 11 outputting a second detecting output when power-supply voltage reaches a set value (80V) lower than the set value (95V) or less successively after the first detecting output is output and continues for a fixed period (20-100ms) are provided. Accordingly, service interruption can be detected at higher speed with higher reliability than a conventional example, in which service interruption is discriminated only by power-supply voltage. A fault at an apogee where power-supply frequency is lowered only in a moment.
Inventors:
Ichiro Kasama
Koji Watanabe
Tetsuro Iwakiri
Yasuyuki Okuda
Koji Watanabe
Tetsuro Iwakiri
Yasuyuki Okuda
Application Number:
JP8547192A
Publication Date:
May 13, 2002
Filing Date:
April 07, 1992
Export Citation:
Assignee:
Tokyo Gas Co., Ltd.
Omron Corporation
Omron Corporation
International Classes:
H02H3/24; H02H3/46; (IPC1-7): H02H3/46; H02H3/24
Domestic Patent References:
| JP1176948A | ||||
| JP1298915A | ||||
| JP478572U | ||||
| JP1123427U |
Attorney, Agent or Firm:
Kazuhide Okada
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