how to do SF6 gas circuit breaker test

SF6 (sulfur hexafluoride) circuit breaker is a high-voltage electrical switchgear device that uses SF6 gas as its insulating and arc-quenching medium, commonly employed in medium to high-voltage power transmission and distribution systems.

1. 𝗖𝗼𝗻𝘁𝗮𝗰𝘁 𝗥𝗲𝘀𝗶𝘀𝘁𝗮𝗻𝗰𝗲 𝗧𝗲𝘀𝘁
𝐏𝐮𝐫𝐩𝐨𝐬𝐞:
Measures the resistance of main contacts to ensure efficient current flow and prevent overheating.
𝐏𝐫𝐨𝐜𝐞𝐝𝐮𝐫𝐞:
1.Use a Micro-ohmmeter (Mjolner 200 tester).
2. Apply a DC current (typically 100A or more).
3. Measure the voltage drop and calculate resistance using R = V/I.
𝗔𝗰𝗰𝗲𝗽𝘁𝗮𝗻𝗰𝗲 𝗖𝗿𝗶𝘁𝗲𝗿𝗶𝗮:
High resistance indicates wear, contamination, or poor connection.

2.𝗧𝗶𝗺𝗶𝗻𝗴 𝗧𝗲𝘀𝘁 (𝗢𝗽𝗲𝗿𝗮𝘁𝗶𝗼𝗻𝗮𝗹 𝗧𝗲𝘀𝘁)
𝐏𝐮𝐫𝐩𝐨𝐬𝐞:
Ensures the breaker operates within specified opening and closing times.
𝐏𝐫𝐨𝐜𝐞𝐝𝐮𝐫𝐞:
1. Use a Circuit Breaker Analyzer.
2. Measure:
Opening time
Closing time
Bounce time
3. Compare results with manufacturer specifications.
𝗔𝗰𝗰𝗲𝗽𝘁𝗮𝗻𝗰𝗲 𝗖𝗿𝗶𝘁𝗲𝗿𝗶𝗮:
Opening time: 20–60 ms
Closing time: 30–80 ms
Differences between phases should
be minimal.
3.𝗦𝗙₆ 𝗚𝗮𝘀 𝗟𝗲𝗮𝗸𝗮𝗴𝗲 𝗧𝗲𝘀𝘁
𝐏𝐮𝐫𝐩𝐨𝐬𝐞:
Detects gas leaks to ensure proper insulation and arc-quenching performance.
𝐏𝐫𝐨𝐜𝐞𝐝𝐮𝐫𝐞:
1. Use an SF₆ Gas Leak Detector or thermal imaging camera.
2. Scan around seals, flanges, and gas compartments.
𝗔𝗰𝗰𝗲𝗽𝘁𝗮𝗻𝗰𝗲 𝗖𝗿𝗶𝘁𝗲𝗿𝗶𝗮:
SF₆ leakage should be < 0.5% peryear (as per IEC 62271-203).

4.𝗦𝗙₆ 𝗚𝗮𝘀 𝗣𝘂𝗿𝗶𝘁𝘆 𝗧𝗲𝘀𝘁
𝐏𝐮𝐫𝐩𝐨𝐬𝐞:
 Measures SF₆ gas concentration to ensure insulation quality.
𝐏𝐫𝐨𝐜𝐞𝐝𝐮𝐫𝐞
1. Use an SF₆ Gas Analyzer.
2. Measure SF₆ purity percentage.
𝗔𝗰𝗰𝗲𝗽𝘁𝗮𝗻𝗰𝗲 𝗖𝗿𝗶𝘁𝗲𝗿𝗶𝗮:
SF₆ purity should be ≥ 99.5%.
Lower purity requires gas
replenishment.

5.𝗦𝗙₆ 𝗗𝗲𝘄 𝗣𝗼𝗶𝗻𝘁 𝗧𝗲𝘀𝘁 (𝗠𝗼𝗶𝘀𝘁𝘂𝗿𝗲 𝗧𝗲𝘀𝘁)
𝐏𝐮𝐫𝐩𝐨𝐬𝐞.Checks for moisture contamination, which affects insulation performance.
𝐏𝐫𝐨𝐜𝐞𝐝𝐮𝐫𝐞
1. Use an SF₆ Dew Point Meter.
2. Measure the dew point in °C.
𝗔𝗰𝗰𝗲𝗽𝘁𝗮𝗻𝗰𝗲 𝗖𝗿𝗶𝘁𝗲𝗿𝗶𝗮:
 Dew point ≤ -40°C at operating
pressure.
 High moisture content leads to
insulation failure.
6.𝗗𝘆𝗻𝗮𝗺𝗶𝗰 𝗖𝗼𝗻𝘁𝗮𝗰𝘁 𝗥𝗲𝘀𝗶𝘀𝘁𝗮𝗻𝗰𝗲 𝗠𝗲𝗮𝘀𝘂𝗿𝗲𝗺𝗲𝗻𝘁 (𝗗𝗖𝗥𝗠)
𝐏𝐮𝐫𝐩𝐨𝐬𝐞.
Measures resistance changes during breaker operation.
Detects contact wear and SF₆ nozzle condition.
𝐏𝐫𝐨𝐜𝐞𝐝𝐮𝐫𝐞
1. Use a DCRM test set.
2. Measure resistance during
3. Analyze for wear and erosion.
𝗔𝗰𝗰𝗲𝗽𝘁𝗮𝗻𝗰𝗲 𝗖𝗿𝗶𝘁𝗲𝗿𝗶𝗮:
The resistance curve should be smooth.
High resistance peaks indicate
damaged arcing contacts.