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).
What is EHV/HV GIS Disconnect Switch?
An EHV/HV GIS Disconnect Switch, part of Gas Insulated Switchgear (GIS), is a critical component in electrical systems designed for handling Extra High Voltage (EHV) or High Voltage (HV) applications. GIS technology employs sulfur hexafluoride (SF6) gas as an insulating medium, allowing for a more compact and efficient design compared to traditional air-insulated switchgear. The disconnect switch within GIS serves as a mechanical isolator, ensuring the safe and visible isolation of specific sections of the electrical circuit. This feature is essential for maintenance activities or other operational requirements, enhancing the overall reliability and safety of the electrical grid. EHV/HV GIS Disconnect Switches find widespread use in high voltage substations, power transmission systems, and industrial facilities where the optimization of space and dependable electrical operation is paramount. Their gas-insulated and compact design, along with the ability to handle high voltage levels, makes them instrumental components in ensuring the efficient and safe functioning of electrical networks.
Discover more from PAKTECHPOINT
Subscribe to get the latest posts to your email.