Matters during the vacuum circuit breaker test process
The following are some common issues related to the transfer of vacuum switch operations during testing:
1、 New testing items for vacuum circuit breakers, including:
1. Accurately measure the resistance of the ground; 2. A resistor used to accurately measure the conductivity loops of each phase; 3. Communication stress testing; 4. Accurately measure the opening and closing time of the switch, accurately measure the accuracy of closing, accurately measure the closing time, and accurately measure the tripping time after closing; 5. Accurately measure the ground resistance and resistance measurement of the opening and closing electromagnetic coils and the closing electromagnetic induction coils; 6. Test the switch operating mechanism.
2、 Accurately measure the resistance value of the ground wire: 1. Accurately measure the resistance value of the entire ground wire, please refer to the manufacturer's specific regulations; In the "Handover Test Standards for Oil Circuit Breakers", under the specified environment, the grounding resistance of the insulation layer support rod should be less than or lower than the provisions described in this article.
3、 Accurately measure the resistance of each phase conductive ring: Select a ring insulation testing machine with a current of not less than 100 A, and the test results must comply with the requirements of commercial technical specifications.
4、 AC voltage withstand test should be conducted in both switch and closed states: when in closed state, the test working voltage should comply with the provisions of the "Oil Circuit Breaker Handover Test Standard". If carried out in a vacuum state, the working voltage tested on the rupture surface of the vacuum blowing box must comply with commercial technical specifications, and there must be no through type charging and discharging during the testing process.
5、 Accurately measuring the opening and closing time of the switch, accurately measuring the accuracy of closing, and accurately measuring the tripping time during the entire closing process should meet the following requirements: 1. The jumping time after the circuit breaker is touched during the entire closing process should not exceed two meters for circuit breakers below 40.8 kV. Switches above 40.8 kV shall not exceed 3 milliseconds; 2. Strict testing should be conducted according to the working voltage of the circuit breaker and the working pressure of the hydraulic machinery; 3. The evaluation indicators must comply with the technical specifications of the product.
6、 Accurately measure the ground resistance of the opening and closing electromagnetic coils and the closing electromagnetic induction coil, which shall not be less than 10 M ohms; In actual testing, there is no significant difference between the resistivity and the actual test results of the product.
7、 The testing of the circuit breaker operating mechanism must comply with the following regulations: 1. When the actual operating voltage and hydraulic press are within the following types, the operating organization should be reliable; The operating voltage of the circuit breaker control organization switch, hydraulic press type operating voltage: DC (85%~110%) Un; （85%~110%)； Hydraulic machinery: According to the minimum and maximum power specified by the product: (1) For EMI structures, when the maximum switching rate of the circuit breaker does not exceed 50 kA, the operating current type is (80%~110%) Un. Un is the rated supply voltage. (2) The posture specifications for the closed electromagnetic coil of the torsion spring and hydraulic press operating mechanism, as well as the closed AC contact device of the electromagnetic operating mechanism, must comply with the requirements of the previous item. 2. Practical operation of detachable type: (1) When the working voltage at both ends of its electromagnetic winding is higher than 65% of the rated value, the valve must be reliably disconnected; When the working voltage is below 30%, it does not need to be disconnected; (2) When installing an overvoltage switch, its posture characteristics must comply with the following regulations; The ratio of supply voltage to nominal supply voltage:
vacuum switch
Operating conditions with voltage levels exceeding 85% and 35% or more:
The iron core should be reliably loosened, but it cannot be loosened and must be reliably absorbed.
(1) When the working voltage slowly drops to the required ratio, the core must be reliably released.
(2) Install an overcurrent switch with a current rating of not less than 2.5 A and meet the following conditions: discharge current level and accuracy. The types of overcurrent switches with delayed posture are classified as discharge current levels (A) 2.5-102.5-15. The discharge current accuracy for each stage is+10% -10%. The different discharge current accuracy for the same switch is ± 5% -5%. Note: For overcurrent switches with delayed posture, the relationship curve between discharge current and posture delay provided by the manufacturer must be used for verification. In addition, when the main circuit current drops to the transmission parameter before the scheduled delay is terminated, the switch should also be checked to be non functional.
3. Simulation operation test:
(1) With stable voltage, switches can be operated on-site or remotely under different working voltages and hydraulic standards. Each actual switch should be correct and reliable, and the action of its interlocking and locking devices must meet the requirements of the product and design; Test only at rated voltage without stable voltage regulation;
(2) The operation testing of magnetic or torsion spring structures powered by DC must comply with the following regulations; The operation testing of hydraulic devices must be carried out in accordance with the following regulations.
