Relay Testing Solutions: Secondary Injection Test for Reliable Protection

Secondary Injection Test and Primary Injection Test: Two Sides of the Same Coin

When it comes to ensuring reliable relay protection, both secondary injection tests and primary injection tests play critical roles. While the secondary injection test focuses on individual components like relay testing, it’s equally important to evaluate the entire protection circuit. This is where primary injection testing becomes essential, as it not only checks the protection scheme but also verifies CT/VT ratios, polarity, and phasing.

The primary injection test is typically conducted after the secondary injection test to ensure that any problems are confined to the transformers (CTs and VTs) and their associated wiring, since the secondary injection test will have already verified the functionality of the remaining equipment. Both tests complement each other, offering two sides of the same coin; one does not exclude the other.

If primary injection testing isn’t possible, a secondary injection test can still detect issues like wiring and connection faults, which could otherwise go unnoticed if only the relays are tested. However, transformers must be tested separately, as secondary injection testing cannot confirm the correct ratios or outputs of transformers, nor detect transformer saturation. Proper transformer connections are crucial for correct relay operation, as phase angles of voltages and currents reaching the relays are influenced by transformer connections and intermediate wiring.

The secondary injection test simulates the secondaries of current and voltage transformers by injecting single-phase or three-phase currents and voltages into relays, devices, or secondary circuits. This enables thorough testing under both normal and fault conditions, ensuring the reliability of the system.

The Widest Range of Equipment for Secondary Injection Tests

SMC has been a leader in manufacturing equipment for secondary injection tests for over 30 years. Our extensive experience has allowed us to develop a comprehensive range of secondary injection test sets, from simple and autonomous devices to fully automated systems designed for rapid and accurate testing across various applications.

Featured Secondary Injection Test Sets

• QUASAR: The Quasar is our most advanced three-phase relay test set, specifically designed for secondary injection testing and IEC-61850 protections. Ideal for industrial and routine maintenance applications, the Quasar adds modularity, allowing users to expand testing capabilities based on their needs.

• PTE-100-C Series: As a world leader in single-phase secondary injection test sets, the PTE-100-C is the lightest and most portable option available. With up to 250 A of current and 1000 VA power, this device delivers fast and accurate secondary injection tests at a competitive price. It’s an essential tool for any plant or substation.

• PTE range: This series of digital, non-variac-based secondary injection test sets offers high accuracy and stability, including single-phase and three-phase options. These portable units are perfect for relay testing, dynamic fault testing, and interconnection with other testing equipment.

• MENTOR 12: A universal secondary injection test set with a modular design, the MENTOR 12 offers up to 12 channels and integrates advanced built-in test tools. With its intuitive touch-screen interface, it is ideal for secondary injection tests and relay testing without the need for an external PC.

• PME-20-PH: This digital phase angle meter is perfect for phase deviation checks in any secondary injection test setup. It measures angles between voltages, currents, or both, enhancing accuracy in relay protection testing.

• PTE-30-CH: the portable digital timer PTE-30-CH is other SMC accessory which can be used for measuring trip time in relays and any pulse or time between two electrical events.

• GOOSEMeter one: Designed for IEC 61850-based networks, the GOOSEMeter One monitors GOOSE traffic, ensuring reliable communication during secondary injection tests.

• LET-400-RD/RDC: Our primary injection test units can also be used as sources for secondary injection tests when higher current ranges are required. These units provide up to 400 A continuously and feature low current taps for secondary injection test flexibility.

• RAPTOR: With greater power and stability, the RAPTOR multifunctional system can also be utilized for secondary injection tests. The Raptor Polarity Tester accessory further simplifies polarity testing in secondary circuits.

SMC’s equipment is designed to be user-friendly and highly reliable, ensuring seamless execution of secondary injection tests. Our complete range of secondary injection test sets and accessories provide all the tools you need for effective relay protection testing.

For more information on our secondary injection test sets or other products, please check the related SMC offerings or contact us directly.