The Types JBC, JBCG and JBCV relays consist of three units, an instananeous power-directional unit (bottom) of the induction-cup type, a time overcurrent unit (middle) of the induction-disk type, and an instantaneous-overcurrent unit (top) of the induction-cup type. The directional-unit contacts control the operation of both the instantaneous and the time-overcurrent units (directional control). In this application, the instantaneous unit provides high-speed protection for close-in high-current faults.