INGVAR primary current injection test system
Primary injection testing of protective relay equipment and circuit breakers
Primary injection testing of protective relay equipment and circuit breakers
Key Benefits
- Up to 5000 A output current
- Simplified transportation
- Unique I/30 function
- In parallel mode. Maximum generation time 2s. Load voltage 1.2 V.
Description
The system consists of a control unit and a current unit. The two parts are portable, and INGVAR can be quickly assembled and connected.
The control unit has many advanced features, such as a powerful measurement section that can display turns ratio as well as time, voltage, and current. A second measurement channel can also be used to test an additional current or voltage.
The INGVAR can calculate the current transformer turns ratio, impedance, power, power factor/tan delta (cos φ), and phase angle and the results are shown on the display. The current and voltage can be presented as percentages of nominal value. It also has a fast-acting hold function that freezes short-duration readings on the digital display, so when the voltage or contact signal arrives at the 'stop' input, the object under test interrupts the current, or the injection is stopped.
Specifications
Frequently Asked Questions
What is primary injection testing?
Primary injection testing is a method where high currents, typically in the hundreds to tens of thousands of amps, are injected into the test circuit to replicate actual currents the circuit will encounter during operation. Primary injection testing is most often used for testing current transformers (CTs) and low voltage circuit breakers. You can also use primary injection testing to test a complete circuit. For a test of the complete circuit, a high current is injected on the primary side of the current transformer. The test covers the entire chain, e.g., current transformer (CT), conductors, connection points, relay protection, and sometimes circuit breakers. You must take the system being tested out of service during primary injection testing. Testing is usually conducted in connection with commissioning.For testing a CT’s ratio and polarity with primary injection, current is injected into the CT’s primary winding, and the resulting current is measured on the secondary circuit.For testing a low voltage circuit breaker with primary injection, the current is injected through the circuit breaker, and the trip times are measured. The only way to verify that a direct-acting, low voltage circuit breaker operates properly is to inject a high current. Typical testing times are long time, short time, and instantaneous trip.
Are there alternative applications for which I can use the INGVAR besides trip times for circuit breakers?
The two most common applications of the INGVAR are primary current injection of low voltage circuit breakers and primary injection testing of current transformers (measuring ratio, polarity, and phase angle). In addition to these two applications, you can use the ODEN for heat run tests. Moreover, you can test automatic reclosers and sectionalisers with the INGVAR. The instrument allows you to set custom operating limits, partial times, total times, and the number of operations before lockout.
Can the INGVAR be used to test medium and high voltage circuit breakers?
The primary application of the INGVAR test set is testing low voltage circuit breakers (less than 1000 V). A circuit breaker analyser is needed to test medium and high voltage circuit breakers. Megger manufactures three different analysers: the EGIL, TM1700, and TM1800, to meet all your circuit breaker testing applications.
How does the INGVAR record the trip time of the CB?
The INGVAR provides several methods to record the trip time. The most common one is to use the internal detection INT. This setting configures the INGVAR to record the time the current stops flowing. In addition to the INT setting, you can select to detect the opening or closing of a contact or the application or interruption of voltage to determine the stop input.
Does the INGVAR have built-in time-current curves for various circuit breakers?
No, you manually control the current using a rotary dial and will need to test to the manufacturer’s specifications. The Megger Smart Primary Injection (SPI) test is available if you want a fully automated test set.
