How to Assess the Quality of a Current Transformer

Abnormal readings on the  are often seen as a decrease or zero value. The current circuit used for meter measurement may have an open circuit, leading to inconsistent readings on three-phase ammeters, reduced power meter indications, and slow or non-functioning meter rotation. In some cases, if the meter occasionally shows no readings, it may be due to a semi-open circuit state (poor contact).

Check for any noise, uneven vibrations, excessive heat, smoke, or other unusual occurrences in the current transformer body. However, these signs may not be apparent when the transformer is under load.

Be cautious of smoke and burnouts in electricity meters, relays, and other devices. If reactive power meters, kilowatt-hour meters, remote control transmitters, or protection relay devices burn out, it can result in not only a secondary open circuit in the current transformer but also a secondary short circuit in the potential transformer.