13
Residual Ground Fault
Safety Manual MN042004EN March 2017 www.eaton.com
CAUTION
The motor, the wiring diameter and the switching device(s)
must be suitable for the selected Trip Class.
CAUTION
The current-dependent protective device must be selected
so that not only is the motor current monitored but the
blocked motor is switched OFF within the temperature rise
time.
Current Phase Loss
The Current Phase Loss protection monitors the current unbal-
ance of the motor and will trip the motor if the unbalance
exceeds the set threshold. The Current Phase Loss protection
is active when the motor is in the Running state.
If a C445 relay is commissioned to monitor an AC motor, the
current must be fed on all three poles to prevent early tripping.
Measurement Precondition Imax>50% of FLA, Imin<25% of
FLA, No V Phase Loss (or no voltage option)
Measurement Parameter Current unbalance percent
Protections —> Current —> I Phase Loss
Current Phase Loss
Delay (Seconds)
Fault Code Protection Action Modbus Fault Action Units Min. Max. Default Min. Max. Default Modbus
5 Current Phase Loss Fault Trip 1016 % 60 60 60 2 2 2 1017
Ú
If the C445 relay is commissioned to monitor an
AC motor, the current must be fed on all three
poles in order to prevent early tripping. DC motors
cannot be monitored.
CAUTION
The device settings of the C445 allow a deactivation of the
phase loss sensitivity refer User Manual for further details.
To avoid potential motor overheating, do not deactivate
the phase loss sensitivity when using the C445 motor
management relay to protect the motor in a potentially
explosive environment.
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