Surge Arrester Test Procedure

Testing surge arresters is crucial to ensure their proper functioning and ability to protect electrical equipment from transient overvoltages. Below is a general test procedure for surge arresters. Specific procedures may vary based on the type and manufacturer of the surge arrester. Always refer to the manufacturer’s documentation for the most accurate and detailed information.

To guide the responsible persons in conducting Surge Arrester Tests.

Preparation:

• Ensure all personnel involved in the testing are qualified and familiar with safety procedures.
• Review the manufacturer’s documentation, including manuals and drawings, for the surge arrester.
• Verify that the equipment is de-energized and properly isolated.
• Confirm that all necessary safety precautions are in place, including personal protective equipment (PPE).

SAFETY PRECAUTIONS – The following Safety precautions shall be taken in consideration prior, during and after conducting the test measurements.

• Safety tagging shall be implemented.
• Isolate the Area by Safety Warning Tape.
• Keep a Safe Distance from the device being tested.
• Wear Appropriate Personal Protective Equipment(PPE) Prior to starting any testing activity.
• Implementation of Proper Grounding.

TEST EQUIPMENTS: Power Factor Insulation Test Equipment, Ammeter, IR Tester, EHV/HV Tester.

Surge Arrester Test Procedure

1. Setup the CALIBRATED test instrument/s to be used in a firm, reasonably level base and dry area.
2. Thoroughly clean all Bushings of the surge arresters to be tested.
3. Perform Insulation Resistance Testing with injected DC voltage of 2.5kV as per the following test connections.

3.1 Repeat the test connections on applicable arresters for the Other 2 phases Y and B.
3.2 Record test results on applicable test forms and evaluate as per standards. (> 1 MΩ).

Perform the Dissipation Factor (tan δ) test as per the below test connections:

4.1 Repeat the test connections on applicable arresters for the Other 2 phases Y and B.
4.2 Record test results on applicable test forms and evaluate as per standards.(0.5%)

5. Perform the Leakage reactance test as per the below test connections:
   5.1 Connect the EHV/HV Tester with a rated voltage to Surge arrester as per the below test connection:

5.2 Measure the Leakage Current for Phase R as shown above with the earth disconnected.
5.3 Repeat step 5.2 for phases Y and B
5.4 Record measured values in applicable test forms. Leakage current measured must not exceed 30mA (I_leakage ≤ 30mA).

General Instructions for Surge Arrester Test:

1. Visual Inspection:
   • Inspect the surge arrester for any visible signs of damage, such as cracks, leaks, or corrosion.
   • Check for proper installation and grounding.
   • Verify that external connections are secure.
2. Insulation Resistance Test:
   • Measure the insulation resistance of the surge arrester using an insulation resistance tester.
   • Ensure that the insulation resistance values are within the specified range.
3. Impulse Test:
   • If an impulse generator is available, perform an impulse test to simulate lightning strikes or switching surges.
   • Measure the voltage across the surge arrester during the impulse.
   • Compare the measured voltage with the arrester’s rated impulse withstand voltage.
4. Voltage Measurement:
   • Use a multimeter or voltage transformer to measure the voltage across the surge arrester under normal operating conditions.
   • Verify that the voltage is within the rated continuous operating voltage of the surge arrester.
5. Leakage Current Measurement:
   • Measure the leakage current flowing through the surge arrester under normal operating conditions.
   • Ensure that the leakage current is within the manufacturer’s specified limits.
6. Resistance Measurement:
   • Measure the resistance of the surge arrester’s internal components using an ohmmeter.
   • Compare the measured resistance values with the manufacturer’s specifications.
7. Oscilloscope Test (if applicable):
   • Use an oscilloscope to analyze the waveform of the voltage across the surge arrester during transient events.
   • Ensure that the waveform characteristics meet the specified criteria.
8. Documentation:
   • Record all test results, including measurements and observations.
   • Compare the results with the manufacturer’s specifications.
   • Document any deviations from specifications and actions taken to address them.
9. De-Energization:
   • Safely de-energize the surge arrester.
   • Restore any safety devices or barriers that were removed for testing.
10. Report:
    • Prepare a comprehensive test report summarizing the procedures, results, and any recommended actions.
    • Include any deviations from specifications and actions taken to address them.

Always prioritize safety during testing, and follow all safety guidelines and procedures. If you are not familiar with the testing procedures or if there are any doubts, consult with qualified personnel or the surge arrester manufacturer.