Primary Injection Test of Current Transformer
Primary injection testing of a current transformer means injecting a known primary current through the transformer and measuring what comes out of the secondary circuit, including the relay or meter connected to it. It differs from secondary injection, which tests the relay alone: primary injection tests the whole chain, transformer, wiring and relay together.
The primary injection sets in the manufacturer's range cover a wide current span: the TEST-901 family starts at 1100A class, with larger sets to 2200A, 3300A and 5500A class, and a portable 200A kit for smaller work. The set must deliver the primary current the transformer rating requires, with enough capacity for the burden connected.
A primary injection test plan should state the test currents, the expected secondary currents from the ratio, the relay or meter settings under test, and the pass criteria before the test starts. Record the injected current, the secondary current, the ratio error, the polarity observation, and the breaker or relay operating time where timing is part of the test. Temperature rise testing on larger sets is a separate test with its own duration and limits; do not treat a short ratio test as a temperature rise test.
Before ordering, confirm the primary current range needed, the test functions required, and the delivery terms. Ask for the current datasheet to be confirmed in writing before ordering.
Figures on this page come from the manufacturer's own category pages, manufacturer-hosted datasheets, or a shop listing stated as such. Where the reference material does not settle a figure, this site states that it is unresolved and publishes no figure, rather than choosing one.
What to confirm before ordering
Before payment, confirm the model, the specification from the current datasheet, the quantity, the price, the lead time, and the delivery terms, in writing. Ask in your inquiry to confirm the payment terms, the trade terms, and the reply time you should expect, rather than assuming any of them. No price, minimum order or lead time figure is stated on this site.
Send an inquiry: include the model, the test or measurement requirement, and the quantity you need. Before payment, confirm the model, the specification from the current datasheet, the quantity, and the delivery terms.