Allen-Bradley 1407-CGCM, User Manual, Page: 55 / 252

Rockwell Automation Publication 1407-UM001H-EN-P - November 2014
CGCM Unit Operation #HAPTER
The CGCM unit can be used as primary protection in applications not requiring
utility grade protection or in utility applications where the authority having
jurisdiction has approved the CGCM unit for use as primary protection. In
applications requiring utility grade protection, where the local authority has not
evaluated or approved the CGCM unit, the CGCM unit can be used for
secondary protection in conjunction with a primary protection system.
,OSSOF%XCITATION#URRENT
The CGCM unit activates this fault when excitation current metered by the
CGCM unit falls below the user specified loss of excitation current setpoint for
more than the user defined delay time. In a redundant CGCM unit system,
excitation is disabled and a transfer to the secondary controller occurs. If this fault
occurs, tag
LossExcFlt = 1 in the Scheduled Read table. This fault is inhibited
during voltage build and when soft start is active.
/VEREXCITATION6OLTAGE& FIELDOVERVOLTAGE
When the field voltage rises above the level you specified for more than a set
amount of time, a field over-voltage annunciation occurs. Once the field voltage
drops below the threshold, the field over-voltage timer is reset. If this fault occurs,
the CGCM unit shuts down excitation and sets tag
OvrExcFlt = 1 in the
Scheduled Read table.
'ENERATOR/VERVOLTAGE
When the generator voltage rises above the level you specified for more than a set
amount of time, a generator over-voltage annunciation occurs. Once the
generator voltage drops below the threshold, the generator over-voltage timer is
reset. If this fault occurs, tag
Ovr_V_Flt = 1 in the Scheduled Read table.
'ENERATOR5NDERVOLTAGE
When the generator voltage falls below the level you specified for more than a set
amount of time, a generator under-voltage annunciation occurs. Once the
generator voltage rises above the threshold, the generator under-voltage timer is
reset. This function is disabled during soft start timing or when the
EngineIdle
tag is set. If this fault occurs, tag Undr_V_Flt = 1 in the Scheduled Read table.