14
3 Line protection setting description
PXR tRiP units foR PoweR Defense molDeD case ciRcuit bReakeRs
MN012007EN March 2019 www.eaton.com
Protection Function Actions
The protection functions can also be configured to take one of 3 actions;
1. Trip the breaker with alarm
2. Alarm only, do not trip
3. Be totally disabled
Hntt:
H
On the PXR25 LCD, use
MaHn Menu > SettHngs > Motor > Feature
to set one of the
3 actions. Or in PXPM for both the PXR 10 and PXR 25, use the drop-down menus
under the setpoint configuration.
Protection Function: Over Voltage
Line-to-line RMS voltages (Vab, Vbc, Vca) are continuously monitored. If any line-to-line
voltage is greater than the pickup setpoint for the specified time delay, then the configured
protection action will be taken.
Protection Function: Under Voltage
If any line-to-line voltage is less than the pickup setpoint for the specified time delay, then
the configured protection action will be taken.
otet:
N
Setpoint ranges for under voltage and overvoltage overlap. If both are used in an
application, under voltage pickup should always be set less than over voltage pickup.
If under voltage pickup is set higher than overvoltage pickup and the breaker is
closed, the trip unit will see one or both conditions pickup satisfied, begin timing and
trip.
Protection Function: Voltage Unbalance
If the difference between the maximum and minimum of any of the 3 line-to-line voltages
is greater than the pickup for the specified time delay, then the configured protection action
will be taken. Action will be taken only when at least one line-to-line voltage is greater than
84 V.
The calculation for the voltage unbalance pickup is:
Protection Function: Current Unbalance
The RMS current in each of the phases (Ia, Ib, Ic) is continuously monitored. Unbalance
protection will protect against partial or full loss of one or two phases. If the difference
between the maximum and minimum of any of the 3 phase currents is greater than the
pickup for the specified time delay, then the configured protection action will be taken. The
Long Delay indicator on the front panel will illuminate. Action will be taken only when at
least one phase current is greater than 50% of the FLA setting (0.5 x I
e
).
The calculation for the current unbalance and phase loss pickup is:
Protection Function: Phase Loss
Phase loss protection is used for complete loss of one or two phases. If the difference
between the maximum and minimum of any of the 3 phase currents is greater than 75%,
for the specified time delay, then the configured protection action will be taken. Action will
be taken only when at least one phase current is greater than 50% of the FLA setting
(0.5 x I
e
).
Protection Function: Phase Rotation
The phase relationship of the line-to-line voltages is continuously monitored. If the phase
sequence is different from the setting, then after the fixed time delay, the configured protec-
tion action will be taken. Action will be taken only when at least one line-to-line voltage is
greater than 84 V.
Max(Vab,Vbc,Vca)-Min(Vab,Vbc,Vca)
Max(Vab,Vbc,Vca)
x 100%
Max
x(Vab,Vbc,Vca)
Max(Ia,Ib,Ic)-Min(Ia,Ib,Ic)
Max(Ia,Ib,Ic)
x 100%
