The testing of EHV/HV GIS (Extra High Voltage/High Voltage Gas Insulated Switchgear) disconnect switches is essential to ensure their proper functioning, reliability, and compliance with industry standards.
TEST EQUIPMENTS: Megger IR test Kit, Contact Resistance Test Kit, Circuit Breaker Analyzer.
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.
EHV/HV GIS Disconnect Switch Test Procedure
Perform the Insulation Resistance test.
1.1 Remove the Earthing Wire Termination as shown in the below diagram.
1.2 Closed the associated Earth Switches of each the Disconnect Switch’s phases.
1.3 Inject 5kV DC for 1 minute as per the following Phase to ground test connection diagram and repeat for the remaining
phases Y and B.
1.4 Repeat the Test for phase to phase (R to Y, Y to B and R to B) connection as per the the following diagram:
1.5 Record the measured values in the applicable test forms and evaluate as per acceptable standards/criteria (>100 MΩ ).
Perform the Contact Resistance test.
2.1 Remove the Earthing Wire Termination as shown in the below diagram.
2.2 Closed the associated Earth Switches of each the Circuit Breaker’ phases.
2.3 Inject 100A DC for 1 minute as per the following test connection diagram and repeat for the remaining phases Y and B.
2.4 Record the measured Voltage Drop.
2.5 Record the measured resistances in the applicable test forms and evaluate as per acceptable standards/criteria: (< 300 microΩ).
Perform the OPEN and CLOSE Timing test as per the following Test connection diagram.
3.1 Print Record the measured values in the applicable test forms and evaluate as per acceptable standards/criteria (< 20 msec).