Chapter 6—Motor Protection
126
Power Xpert C445 Global Motor Management Relay
MN042003EN—January 2019
www.eaton.com
Voltage Loss Long
The Voltage Loss Long setting is a command to automatically
pull a contactor back in to restart a motor in the event of an
undervoltage condition that has exceeded the Short Time
duration. A user configurable time delay is available to
prevent out of sync starting of motors. In addition to having
the ability to vary Short Time delays for multiple motors, a
second timer can be utilized after Long Time to further avoid
brownouts from motors restarting together based on a
common undervoltage condition. Any voltage loss longer
than Long Time will require the user to manually go through
the restart sequence.
Operation
Main voltage remains below Voltage Loss Level setting for
longer than Voltage Loss Short Time. The contactor and
C445 relay output remain open. C445 will close its relay
output to pull in the contactor if Voltage Return level is seen
within the Long Time interval.
Note:
C445 must maintain control power to execute short
time behavior. If the relay powers down, the C445 will
not execute restart logic. See beginning of section for
more information.
Example #5
Main voltage returns above Voltage Return Level setting in
<VL Long Time. Long Delay Time begins counting. Once
time delay has expired, contactor is pulled back in and motor
is restarted.
Note:
A run signal must be present for restart to occur. If
there is a run permissive in the circuit, it must also
remain active.
Figure 116. Example #5: Long-Time—Mains Voltage Returns Before Long Time Expires
