CT Ratio Test
A CT ratio test checks whether a current transformer delivers the secondary current its ratio promises for a given primary current. The test matters because metering accuracy, protection settings and billing all depend on the ratio being correct, and a wrong ratio is invisible in normal operation until a bill or a protection operation is wrong.
CT analyzers in the manufacturer's range, such as the GF1061 family, test ratio together with polarity, burden, excitation and phase error. The GF1061CT lists ratio testing from 1 to 50000, and the GF106 lists CT ratios to 30000. Primary injection sets such as the TEST-901 family test ratio by injecting primary current and reading the secondary, which also checks the wiring and the connected burden in one run.
A good ratio test record states the test method (analyzer or primary injection), the primary and secondary currents, the calculated ratio, the ratio error, the burden connected during the test, and the transformer identification. Testing at one current only can miss a ratio error that appears at low or high current, so test at more than one point where the standard requires it.
Before ordering test equipment for ratio work, confirm the transformer types, the ratio range needed, whether burden and excitation tests are also 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.