Chapter 6—Motor Protection
120
Power Xpert C445 Global Motor Management Relay
MN042003EN—January 2019
www.eaton.com
Advanced Protection
Voltage Loss Restart
Voltage Loss Restart allows users to select how the C445
unit responds to a mains voltage dip or interruption. The
feature is designed to safely reclose any contactor(s) that
have opened during the voltage loss event. To use Voltage
Loss Restart, traditional undervoltage protection must be
disabled by the user.
Voltage Loss Restart provides three behaviors based on the
duration of the event. The Auto-time interval uses no delay.
C445 will hold its output shut throughout the auto-time
interval so that the contactor will close as soon as enough
current is available (assuming it has dropped out due to the
dip). No time delay is used in Auto Time because the voltage
dip is considered short enough to avoid out of sync restarting
of the motor. The short- and long-time intervals both have
settable restart delays. These delays should be used to
prevent out-of-phase restarting. Both interval periods and
delays can be set individually to each motor, additionally
allowing staggering of restarts within the facility. If a
second mains failure, with duration of less than the
Auto-time interval, occurs within 1s after the first mains
failure, a delayed restart shall be executed, respecting
the delayed restart timeout and resetting to the beginning
of the start sequence.
Two conditions must be present for C445 to execute or hold
a command to close the contactor based on the Voltage Loss
Restart Logic.
1.
C445 must remain powered. If C445 is powered off
120 Vac CPTs from the same mains voltage source as
the motor, control power to the device will also drop
during the event. C445’s ability to remain powered in
this condition depends on the duration and severity of
the Voltage Event. C445 will remain powered for Control
Power dips not exceeding 50% of nominal (120 Vac) for
at least 400 milliseconds. For C445 to remain powered
beyond these conditions, a separate power source and
or/UPS device must be used.
2.
There must be a run signal present. Voltage Loss Restart
is designed to safely re-start motors. C445 will not
re-start a motor if no run signal is present. For this
reason, Voltage Loss Restart should not be used with
fieldwire control that relies on the contactor coil as a
holding circuit because the run signal would drop out
with the contactor. If you are using Voltage Loss Restart
with Fieldwire control in C445, use the following
fieldwire control options:
a
2-Wire Control: A Hand/Off/Auto (HOA) switch with a
maintained Run (Hand) signal.
b
3-Wire Control: Any use of 3-Wire control will work
with Voltage Loss Restart as long as the unit remains
powered. 3-Wire control uses a dedicated start input
and a separate Permissive (stop) Input. The start
input can be momentary or maintained, eliminating
the need for a holding circuit when a momentary
input is used.
Traditional Undervoltage and Voltage Loss Restart Parameters
1
Table 29. Undervoltage
Note
1
Turn off traditional undervoltage protection if planning to use Voltage Loss.
Table 30. Voltage Loss Restart
Fault
Code
Modbus
Fault Action
Delay (Seconds)
Protection
Action
Units
Min.
Max.
Default
Min.
Max.
Default
Modbus
1
Undervoltage
Fault Trip
1028
%
10
100
90
1
60
20
1031
Fault Warning
1029
%
10
100
90
0.2
5
2
1079
Start Trip Delay
Delay Fault Trip at Startup
0
60
20
1030
Fault
Code
Modbus
Fault Action
Delay (Seconds)
Protection
Units
Min.
Max.
Default
Min.
Max.
Default
Modbus
Voltage Loss Auto
1034
Seconds
0.1
0.4
0.2
0
0
0
Voltage Loss Short
1037
Seconds
0.2
5.0
0.4
0.1
500.0
1.0
1035
Voltage Loss Long
1040
Seconds
0
3600
4
1
3600
10
1039
Voltage Loss Level
1032
%
65
90
70
0
0
0
Voltage Return Level
1033
%
80
100
90
0
0
0
