GB/T 39891-2021
Electrical endurance testing for circuit-breakers above a rated voltage of 52 kV (English Version)
- Standard No.
- GB/T 39891-2021
- Language
- Chinese, Available in English version
- Release Date
- 2021
- Published By
- General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
- Latest
- GB/T 39891-2021
- Scope
- This document specifies the general principles of electrical durability tests for circuit breakers of 52kV and above, test samples, electrical durability test procedures separate from standard type tests, electrical durability test procedures combined with standard type tests, no-load tests, wear tests and acceptance testing. This document applies to E2 class SF6 circuit breakers of 52kV and above for overhead lines.
- Introduction
Analysis of the core content of the standard
This standard applies to SF6 circuit breakers with a rated voltage of 52kV and above and used for overhead lines, and focuses on the electrical durability verification method of E2 class (extended electrical life) circuit breakers. The test procedure is divided into two stages: wear test and acceptance test, simulating the accumulated electrical wear within a 25-year maintenance-free cycle.
Comparison of key test requirements
Test type Current level Number of operations TRV requirement T10 wear test 10%Isc 9 times Not applied T60 wear test 60%Isc See Table 2 Not applied L75 acceptance test 60%Isc 3 times Must comply with GB/T1984 LC1 acceptance test Line charging current C1 level 24 times/C2 level 48 times kc coefficient×0.8
Technical points description
Equivalent calculation of electrical wear
In the combined test procedure, different test methods can be converted into equivalent wear through the formula:
0.01N10 + 0.15NOP2 + 0.25N30 + N60 = M90
Where M90 is the benchmark number specified in Table 2, covering 90% of the expected electrical wear.
Innovative method for status inspection
Two alternative schemes are used to verify the insulation status after the acceptance test:
- 72.5kV and below: 80% power frequency withstand voltage test
- Above 72.5kV: 60%~90% switching impulse or T10 TRV waveform test
Implementation suggestions
- Give priority to the test procedure combined with the standard type test to reduce the overall cost
- For GIS circuit breakers, special attention should be paid to the supplementary requirements of GB/T7674
- The capacitive current test should be strictly carried out according to the C1/C2 classification requirements to perform heavy breakdown judgment
- Any maintenance operation is prohibited during the wear test to ensure the continuity of the status
GB/T 39891-2021 Referenced Document
- GB/T 11022-2011 Common specifications for high-voltage switchgear and controlgear standards
- GB/T 1984-2014 High-voltage alternating-current circuit-breakers
- GB/T 2900.20-2016 Electrotechnical terminology.High-voltage switchgear and controlgear
- GB/T 7674-2008 Gas-insulated metal-enclosed switchgear for rated voltages of 72.5kV and above
GB/T 39891-2021 history
- 2021 GB/T 39891-2021 Electrical endurance testing for circuit-breakers above a rated voltage of 52 kV