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Installation & Commissioning of Switchgears & Transformers
The installation and commissioning of switchgears and transformers are critical processes in ensuring the reliability and safety of electrical systems. This blog will guide you through the essential steps involved in these procedures.
Installation of Transformers
1. Foundation Preparation
Before installation, ensure that the foundation is prepared according to the specifications outlined in the design drawings. This includes verifying that all embedded parts are correctly positioned and that the surface is treated adequately to support the transformer’s weight.
2. Transportation and Placement
Transporting the transformer requires careful planning. Use appropriate lifting equipment and ensure that the center of gravity is maintained during lifting. Protect sensitive parts, such as porcelain insulators, to prevent damage during this phase
3. Attachment Installation
Once in place, install necessary attachments like vibration isolators and auxiliary devices such as temperature measuring instruments and control boxes. Ensure that all components are positioned correctly according to high and low voltage sides
4. Connection Work
Connect all electrical lines, ensuring that high-voltage wire packages are intact and positioned correctly. Grounding should be reliable, adhering to code requirements
5. Inspection and Testing
Conduct thorough inspections to ensure all fasteners are secure and connections are correct. This phase includes checking for any physical damage to components during installation.
Pre-Commissioning Tests for Transformers
Before a transformer can be energized, a series of pre-commissioning tests must be performed:
1. Insulation Resistance Testing
Measure insulation resistance values of various windings while ensuring the transformer is disconnected from external lines. These values should match those indicated in the manufacturer’s test reports
2. Oil Testing
Sample oil from different parts of the transformer to check for dielectric strength, which should exceed 50 kV. This testing is crucial for assessing the quality of insulation within the transformer
3. Ratio Testing
Perform ratio tests between high voltage (HV) and low voltage (LV) windings at all tap positions to ensure proper transformation ratios
4. Buchholz Relay Test
Check the operation of Buchholz relays for alarm and trip functions by injecting air into test pockets provided in the relay
5. Control Panel Checks
Verify wiring from various accessories to the control panel, ensuring all connections are correct before energizing the system
Installation of Switchgears
1. Site Preparation
Similar to transformers, switchgear installation begins with site preparation, including verifying foundation integrity and ensuring accessibility for installation equipment.
2. Erection Process
Follow a systematic approach for erecting switchgear, which involves assembling components on-site according to manufacturer specifications and safety standards
3. Electrical Connections
Ensure all electrical connections are made securely, adhering to specified torque settings for bolts and connectors to prevent future failures.
4. Functional Testing
Conduct functional tests on switchgear components such as circuit breakers and protective relays, ensuring they operate correctly under simulated fault conditions
Commissioning Process
The commissioning phase involves several critical checks before putting transformers and switchgears into service:
1. Pre-Energization Checks
Verify grounding integrity, confirm correct phase rotation, and ensure all safety devices are operational before applying power
2. Gradual Energization
When energizing transformers or switchgear, gradually increase voltage levels over a specified period (typically 4-6 hours) to avoid sudden surges that could cause damage
3. Monitoring During Initial Operation
After commissioning, monitor system performance closely for any anomalies or unexpected behavior during initial operation phases.
Conclusion
The installation and commissioning of transformers and switchgears are complex yet vital processes that require meticulous attention to detail at every stage. By following established protocols for installation, pre-commissioning tests, and operational checks, technicians can ensure a safe and efficient power distribution system that meets operational demands while minimizing risks associated with electrical failures. Continuous training and adherence to industry standards will further enhance the reliability of these critical components in power system
