IEEE C57.13.6-2005

This Standard defines one new 0.15 voltage transformer accuracy class, two new 0.15 current transformer accuracy classes, two new current transformer burdens, and two new current transformer routine accuracy test methods. These supplement IEEE Std. C57.13-1993R, Standard Requirements for Instrument Transformers. The new burdens shall be considered for use when current transformers are to be used with electronic meters, and the total in-circuit burden will be less than B0.1 (2.5 Volt-Amperes at 5 Amp, 0.9 power factor) defined in IEEE Std. C57.13-1993R. The new accuracy classes, 0.15 and 0.15S are available to complement the capabilities of solid state electricity metering of equipment associated with the generation, transmission, and distribution of alternating current.

Widespread use of electronic meters and relays necessitate new current transformer test burden definitions, because they present lower impedance than traditional induction devices. This can result in applications where the total circuit burden on the current transformer is less than the lowest IEEE Std. C57.13-1993R definition of B0.1 (2.5Volt-Amperes at 5Amp, 0.9 power factor). Under these conditions, a current transformer meeting a given accuracy class at B0.1 is not assured. In addition, new accuracy classes are needed by industry to to more closely complement the accuracy and dynamic capabilities of modern electronic meters. The new accuracy classes more closely complement the capabilities of electronic meters in both accuracy and dynamic range.

New IEEE Standard - Inactive-Reserved. This standard defines one new 0.15 V transformer accuracy class, two new 0.15 current transformer accuracy classes, two new current transformer burdens, and two new current transformer routine accuracy test methods.