How to Test SF6 Relays in Power Engineering?

In the power system, SF6 relay is a widely used protection and control element, its role is to monitor the SF6 gas pressure in the confined environment of high-voltage switches, GIS, etc., so as to ensure the safe operation of high-voltage switches, GIS and other electrical equipment.

Ⅰ. How to test the installed SF6 relay?

For the SF6 relay test national regulations and specifications, then we need to test the SF6 relay according to these national regulations and specifications, if a SF6 relay before the installation of the test is relatively simple, but more often we are already installed in the electrical equipment SF6 relay for field testing, taking into account the power engineering Timeliness and routine maintenance of electrical equipment require regular testing of SF6 relays, and the site is generally unlikely to allow us to remove the SF6 relay for testing.

Field test SF6 relay, we need to first adjust the valve switch next to the SF6 relay from the monitoring position to the closed position (different manufacturers called different, but the same meaning), close the SF6 relay and GIS and other electrical equipment connection, if not perform this operation, the SF6 relay tester configured gas cylinder simply can not achieve the purpose of controlling the change in air pressure, and can not complete the test.

Again can not directly use the SF6 relay tester wiring to direct wiring, because we close the SF6 relay connection, SF6 relay inside or before the pressure value of the gas, if not the SF6 relay in the previous gas discharge, the SF6 relay itself has a certain pressure, then the density relay tester to control the gas on the SF6 relay to go up the air pressure is also not feasible, resulting in the result is the SF6 relay does not operate. Exhaust gas can be used SF6 relay adapter without any wiring, directly SF6 gas discharge.

After completing the above preparatory operations, then you can follow the test operation according to basically all SF6 relay testers on the market. During the operation, attention should be paid to the ambient temperature, the best situation is to measure when the temperature is constant, because the air pressure has a certain relationship with the temperature, the higher the accuracy of the temperature, the more accurate the test results, the determination of the pressure value at P20 temperature will be more accurate.

Ⅱ. SF6 relay test results judgment and precautions

SF6 relay calibration results with the manufacturer of the density relay alarm and blocking node calibration value and its range (factory value), the pressure gauge calibration only gives the pressure gauge value and the corresponding density relay calibration table to give the pressure value.

Caution

1. Calibration should be correctly selected when the SF6 relay test bench contact socket connection position, to avoid connecting to the density relay normally open or normally closed contacts on the line connected to the wrong.

2. The use of SF6 relay test bench pressure, temperature values should be measured by the calibration department. Calibration cycle according to the national pressure, temperature gauge calibration cycle.

3. This operation test results do not meet the factory value, the test should be reviewed. Confirmation of unqualified, the user of sulfur hexafluoride electrical equipment should be required to deal with.

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