FAQ01545 of Measuring / Motor Protective Relays FAQ

・ZCT (Zero-Phase Current Transformers): Select from the OTG-N Series (through type) or the OTG-D Series (separate type).

・ZPD (Zero-phase Voltage Detection Unit): Select either a VOC-1MS2 (a split-type set with three VOC-1M units and one K3P-M) or a VOC-3S (integrated type).

VOC-1MS2 Zero-phase Voltage Detection Unit

VOC-1M Ratings and Performance

VOC-3S Zero-phase Voltage Detection Unit

VOC-3S Ratings and Performance

Note: Changing between 50-Hz operation and 60-Hz operation can be achieved through selective connections at output terminals.

Note: The following devices are also available if necessary.

OB Ground Fault Protector

A Ground Fault Protector is required for current compensation when an insulation transformer is used in power-receiving equipment, and the ground current on the power supply side (as viewed from the Zero-phase Voltage Transformer) is insufficient for the sensitivity of the relay.

OB Ratings and Performance

AOF-1N Auxiliary Power Supply Unit

An Auxiliary Power Supply Unit is required when using the K2CA-DO Over Current Relay and K2GS-BT Earth-fault Directional Relay in combination, or when using the K2CA-HC Over Current Relay and K2GS-H Earth-fault Directional Relay in combination.