简答题The vacuum circuit breaker is widely applied voltage grade ( ). A、 10～35kV B、110～220kV C、330～750kV D、1000kV简答题220 kv sulfur hexafluoride circuit breaker can generally open circuit short circuit current ( ) without maintenance. A、3 B、20 C、2000 D、30000简答题The function of oil pump in hydraulic operating mechanism of circuit breaker is to change atmospheric pressure oil into high pressure oil. A、正确 B、错误简答题A new transformer substation of 220 kv outdoor distribution equipment is suitable for using in what kind of circuit breaker ( ). A、Compressed air circuit breaker B、Sulfur hexafluoride circuit breaker C、 Vacuum circuit breaker D、Low oil circuit breaker简答题The gas used in the pneumatic operating mechanism of the circuit breaker is ( ). A、Air B、 Hydrogen gas C、 Nitrogen D、 Sulfur hexafluoride gas简答题The hydraulic mechanism of circuit breaker often uses oil is ( ). A、10 aviation hydraulic oil B、Transformer oil C、Gasoline D、Lubricating oil简答题Vacuum circuit breaker contact in which position ( ). A、Vacuum bubble B、Inside the support insulator C、Mechanism box; D、 Inside the insulation rod简答题The dynamic and static contacts of GW5-126 double column disconnecting switch are enclosed in the arc extinguishing chamber (). A、正确 B、错误简答题Check whether the circuit breaker conductive circuit is in good contact, generally do ( ). A、Dc resistance measurement test B、 Mechanical properties test C、Pressure test D、Operating life test简答题In addition to switching on and off load current, the disconnecting switch can also switch on and off short-circuit current (). A、正确 B、错误简答题The limit of high voltage circuit breaker through current refers to ( ). A、The peak current that the circuit breaker can carry in the closed state B、The maximum normal current of the circuit breaker C、The maximum fault current through the circuit breaker when the system fails D、Single phase ground current简答题The rated current of a hV circuit breaker is the maximum continuous current allowed to pass through the device for a long period of time. A、正确 B、错误简答题Which of the following operations does not result in a reduction in oil pressure in a hydraulic actuator ( ). A、Start oil pump B、The circuit breaker closing C、The breaker points brake D、Hydraulic gear oil简答题The following statements about disconnecting switches are correct () A、Isolating switch is a kind of switch without arc extinguishing device B、In the closed state can reliably through the normal operating current C、 Can withstand fault short circuit current and the impact of the corresponding electric force in the specified time D、 Disconnecting switches can normally be switched on or off only if the circuit breaker has already disconnected the circuit简答题The disconnector shall have the following basic requirements () A、Disconnecting switch should have obvious disconnecting point B、Should have enough short circuit stability C、 Disconnecting switch must have electric operation function D、 The main disconnecting switch and the ground switch shall be interlocked简答题Finger contacts are often used in vacuum circuit breakers A、正确 B、错误简答题When the voltage of the switch of the closing coil is lower than the rating of 80%～85%, may ( ). A、Slow switch closing speed B、The fault current is relatively large, which is not conducive to the extinction of arc C、Cause switch refuse to move D、 Cause switch misoperation