发明名称 |
ELECTRICAL SWITCHING APPARATUS WITH DIGITAL TRIP UNIT AND AUTOMATIC FREQUENCY SELECTION |
摘要 |
<p>A microprocessor based switch such as a circuit breaker generates digital rms representations of analog load currents from n samples of the analog currents per cycle synchronized to the line frequency where n is an odd integer equal to a selected highest order harmonic to be detected plus 2. A routine determines whether the power system is 50 or 60 Hz, and automatically sets the sampling interval to provide exactly n samples per cycle for the connected source. Terminals for rapidly resetting an analog memory for calibration and field testing of a long delay trip are hidden behind a removable rating plug.</p> |
申请公布号 |
CA2107319(C) |
申请公布日期 |
2005.05.24 |
申请号 |
CA19932107319 |
申请日期 |
1993.09.29 |
申请人 |
WESTINGHOUSE ELECTRIC CORPORATION |
发明人 |
MURPHY, WILLIAM JOHN;ENGEL, JOSEPH CHARLES;SHIMP, ALAN BURKE;SALETTA, GARY FRANCIS |
分类号 |
H01H71/36;G01R19/165;H01H71/74;H01H73/00;H01H83/02;H02H1/00;H02H3/00;H02H3/093;(IPC1-7):H01H47/00 |
主分类号 |
H01H71/36 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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