Instrument Transformer Testing & Maintenance
Instrument transformers for protection purposes supply protection relays and must also function accurately at a multiple of the nominal current. A regular inspection should ensure that instrument transformers, together with the connected relays, react quickly and correctly in the event of a fault and guarantee the highest possible security of supply. The importance of transformer tests is often underestimated. Risks such as confusing instrument transformers for metering and protection, or mixing up connections can be reduced significantly by testing before initial use. At the same time, damages to the interior of an instrument transformer, caused for example during shipping, can be recognized easily. Also changes in an instrument transformer, caused for example by aging insulation, can be identified at an early stage.
Current Transformer Analysis
O’Hara Engineering use OMICRON’s CT Analyzer is a unique lightweight instrument designed to meet the highest standards for performing excitation, ratio, polarity and winding resistance tests on current transformers (CTs) as well as burden-impedance measurement as well as for testing protection transformers, including those with transient behavior. It can also be used to calibrate instrument transformers due to its high level of accuracy. You can test all essential parameters (ALF/FS, dimensioning factor Ktd, knee point VB) within minutes with just one test cycle.
O’Hara Engineering use OMICRON’s CT Analyzer is a unique lightweight instrument designed to meet the highest standards for performing excitation, ratio, polarity and winding resistance tests on current transformers (CTs) as well as burden-impedance measurement as well as for testing protection transformers, including those with transient behavior. It can also be used to calibrate instrument transformers due to its high level of accuracy. You can test all essential parameters (ALF/FS, dimensioning factor Ktd, knee point VB) within minutes with just one test cycle.
Voltage Transformer Turns Ratio
Transformer Turns Ratio is the ratio of the number of turns in the high voltage winding to that in the low voltage winding. A Transformer Turns Ratio Test Set can directly measure the ratio of single phase, as well as three phase transformers. Transformer ratio can change due to several factors, including physical damage from faults, deteriorated insulation, contamination and shipping damage. If a transformer ratio deviates more than 0.5 percent from the rated voltage ratio, it may not operate reliably. To measure small ratio changes such as this, the accuracy of the test equipment is of the highest importance.
Transformer Turns Ratio is the ratio of the number of turns in the high voltage winding to that in the low voltage winding. A Transformer Turns Ratio Test Set can directly measure the ratio of single phase, as well as three phase transformers. Transformer ratio can change due to several factors, including physical damage from faults, deteriorated insulation, contamination and shipping damage. If a transformer ratio deviates more than 0.5 percent from the rated voltage ratio, it may not operate reliably. To measure small ratio changes such as this, the accuracy of the test equipment is of the highest importance.
