| 摘要 |
1,212,359. Testing switchgear. STARKSTROM-ANLAGENBAU ERFURT VEB. Nov. 7, 1967, No.50500/67. Heading G1U. To test during operation a protective switchgear 5, which includes a voltage transformer 4 and a current transformer 20, respectively responsive to current and voltage in a circuit to be protected, a protective apparatus 25 and control apparatus 26 responsive to fault conditions to operate a circuit breaker 40 and first and second intermediate transformers 22, 17 between the voltage and current transformers and the protective apparatus respectively, the second intermediate transformer having an additional winding 16 for receiving a test voltage, a test equipment 1 is provided including a variable transformer 9 which when suitably energized provides test signals to a test point connectible with the additional secondary winding of the second transformer. The test unit also include a stabilizer and rectifier unit 32 connected to an output of the transformer 9, amplifiers and negator 29, 30, 31, connectible to receive inputs from particular outputs of the protective apparatus and powered from the unit 32, relays 33, 34 connected to the amplifier outputs and controlling signal lamps 37, 36, a further lamp 38 connectible to the control apparatus and a switch device 41 connectible to the control apparatus and settable to prevent operation of the circuit breaker when the switchgear is being subjected to a test, but resettable to allow operation and test of the circuit breaker. The test equipment may be powered from the switchgear voltage transformer 4 or a low voltage supply 3 via protective arrangement 12, and the test equipment may be connected to the switchgear while in use via plug and socket connections. The test signal output from the transformer 9, is fed via a changover switch 10 to the switchgear 5 and the transformer is adjusted to provide a current corresponding to the miniumum which ought to activate the protective and control apparatus 25, 26. The switch 35 enables the relays 33, 34, which are self-holding, to be reset following receipt of outputs from the switchgear indicating a satisfactory test.
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