ZCM Zero Current Message This is a special message that is transmitted whenever the local
breaker is open. If the remote terminal receives a ZCM and at the same
time measures a moderate or large current at its own terminal, this in-
dicates an internal fault.
ZL Load impedance Load impedance
ZS Source Impedance Source Impedance
ZTC Zero True Current Signal Zero True Current Signal
RFL 9300 RFL Electronics Inc.
May 5, 2002 30 - 6 (973) 334-3100