At Technical Engineering Services, we provide comprehensive relay installation, testing, and commissioning services. Our expertise covers various protection relays, ensuring that your electrical systems are secure, efficient, and reliable. Below is a detailed overview of the types of relays we service and the tests we perform for each.

Overcurrent Protection Relays

Overcurrent protection relays are crucial for protecting electrical circuits from excessive current that can lead to overheating and damage. These relays can be configured for instantaneous and time-delayed protection, ensuring the safety and integrity of electrical systems.

Tests We Conduct

1. Current Setting Test

• Purpose: Ensures that the relay operates at the correct current setting.
• Procedure: Apply known current levels to the relay and verify that it trips at the specified set point, confirming that the relay settings align with the protection scheme.

2. Pickup Test

• Purpose: Confirms that the relay will pick up at the predetermined current level.
• Procedure: Gradually increase the current until the relay activates, ensuring that the pickup point matches the configured settings and confirming sensitivity.

3. Time Delay Test

• Purpose: Validates the time delay settings of the relay.
• Procedure: Apply a fault current and measure the time taken for the relay to trip. Compare the results with the configured time delay to ensure accuracy.

4. Reset Time Test

• Purpose: Measures the time required for the relay to reset after tripping.
• Procedure: Trip the relay and record the time taken for it to reset to its normal state. This ensures that the relay can return to operation promptly.

5. Functional Testing

• Purpose: Tests the overall operation of the relay under various conditions.
• Procedure: Simulate different fault conditions, including overcurrent, undervoltage, overvoltage, and underfrequency scenarios, to ensure that the relay responds appropriately and reliably.

6. Undervoltage Protection Test

• Purpose: Ensures the relay trips when voltage drops below the set threshold.
• Procedure: Gradually reduce the supply voltage and verify that the relay activates at the configured undervoltage setting.

7. Overvoltage Protection Test

• Purpose: Confirms that the relay will trip if the voltage exceeds the set threshold.
• Procedure: Apply a voltage higher than the set point and verify that the relay activates, ensuring protection against voltage spikes.

8. Underfrequency Protection Test

• Purpose: Validates the relay’s ability to trip when frequency drops below a specified level.
• Procedure: Gradually decrease the system frequency and confirm that the relay trips at the predetermined underfrequency setting.

Differential Protection Relays

Overview

Differential protection relays are vital for detecting differences in current between two points in a system, typically used for transformers, generators, and feeders. They ensure rapid response to internal faults while remaining stable under external faults.

Tests We Conduct

1. Stability Test

• Purpose: Confirms that the relay remains stable during external fault conditions.
• Procedure: Inject external fault currents and verify that the relay does not trip, ensuring that the sensitivity settings are appropriate for the application.

2. Harmonic Distortion Test

• Purpose: Assesses the relay’s performance in the presence of harmonic currents.
• Procedure: Introduce known harmonic components into the system and verify that the relay responds correctly without unnecessary tripping due to harmonic distortion.

3. Sensitivity Test

• Purpose: Determines the minimum differential current at which the relay will trip.
• Procedure: Gradually adjust the differential current and monitor the relay’s response to ensure it trips at the desired threshold, indicating effective fault detection.

4. Current Transformer (CT) Ratio Test

• Purpose: Ensures that the CTs are functioning correctly and accurately reflecting the primary current.
• Procedure: Measure the secondary output of the CTs at known primary currents and verify that the ratio matches manufacturer specifications.

5. Differential Pickup Test

• Purpose: Confirms that the differential relay picks up and trips when a specific differential current is applied.
• Procedure: Apply a differential current incrementally until the relay activates, ensuring that it meets the designed sensitivity settings for fault detection.

6. Functional Testing

• Purpose: Validates the overall operation of the relay under various fault conditions.
• Procedure: Simulate both internal and external faults to ensure that the relay operates correctly in all scenarios, confirming its reliability in real-world applications.

Distance Protection Relays

Overview

Distance protection relays protect transmission lines by measuring the impedance to a fault. They are essential for ensuring rapid response to short circuits and line faults, helping to isolate affected sections and maintain system stability.

Tests We Conduct

1. Impedance Setting Test

• Purpose: Confirms that the relay operates at the correct impedance setting.
• Procedure: Simulate a fault at various distances along the line and measure the relay’s response to verify that it trips at the appropriate impedance, ensuring effective protection.

2. Reach Settings Test

• Purpose: Validates the reach settings of the relay.
• Procedure: Conduct tests to ensure that the relay responds correctly to faults within the defined reach and does not trip for faults outside the reach, confirming operational integrity.

3. Directional Sensitivity Test

• Purpose: Ensures that the relay correctly identifies the direction of the fault.
• Procedure: Simulate faults from both ends of the line and verify that the relay only trips for faults in the forward direction, which is critical for avoiding nuisance tripping.

4. Functional Testing

• Purpose: Tests the overall operation of the relay under various fault conditions.
• Procedure: Simulate different fault scenarios, including phase-to-phase and phase-to-ground faults, to ensure that the relay responds as expected, confirming its protective capability.

5. Latency and Timing Test

• Purpose: Measures the relay’s response time to ensure it operates within acceptable limits.
• Procedure: Apply fault conditions and record the time taken for the relay to detect the fault and initiate tripping, ensuring that it meets performance standards for speed and reliability.

Your Next Step Starts Here!

Ready to ensure the safety and reliability of your electrical systems? Contact us today to learn more about our extensive relay testing and commissioning services and how we can support your operational needs!