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2. Trip unit description
Power XPert® release triP unit for MagnuM PXr circuit breakers
MN013015EN January 2022 www.eaton.com
2. Trip unit description
The PXR 20/25 is located on the front and to the left side
of the circuit breaker. It is enclosed in a housing which
provides protection to the electronics as well as providing
an interface for a user to configure and monitor operation.
Details of the interface and operation are contained in the
sections which follow.
Shown in Figure 1 are the PXR 20 and PXR 25 trip units.
Both include a back-lit display (LCD) and menu navigation
buttons below the display. The PXR 20 includes rotary
switches for configuring the primary protection settings,
other settings are configured through the menu system.
The PXR 25 configuration is entirely through the menu
system. PXPM also provides an interface for configuring
the trip unit’s settings.
The pictures shown are examples of two styles, the
PXR20VN30LGAM and PXR25VN30LGAM. Certain features
are available only in selected PXR 20/25 trip units.
Figure 1. Trip unit front panels.
2.1 Status indicator
All PXR trip units have an indicator in the top right labeled
STATUS. During normal operation, this indicator blinks
green (on and off approximately once each second), indicat-
ing that the trip unit is operating normally.
The status indicator blinks red if the trip unit detects an
internal problem. This indicates a problem with the trip
actuator coil, a firmware error, or a mechanism switch error.
If the indicator remains on without blinking red or green,
a hardware problem is indicated. Action must be taken to
replace the trip unit or repair the breaker. See Section 7.1 -
Troubleshooting for details.
When the status indicator remains off, either there is no
auxiliary power applied or insufficient primary current to
power the trip unit. PXR trip units will self-power at approxi-
mately 40 A of current in the breaker.
2.2 Display and menu navigation buttons
The PXR trip unit has a display on the front of the trip unit.
This display provides information regarding the operation of
the trip unit and the method to select certain configuration
options. Information is presented on the display in either
English, simplified Chinese, German, French, Spanish, or
Portuguese. Back lighting is included with a power saver
feature that after 30 seconds of inactivity will turn the back-
light off.
When the PXR trip unit is initially powered-up, the display
will briefly show a loading screen and then change to the
Main menu. During this time, the trip unit is already func-
tioning and performing protection operations. Depending
on the trip unit style, submenu selections from the main
menu and further sub-menus for monitoring or configuring
the trip unit. Each submenu can be accessed by pressing
the Down or Up arrow buttons to highlight the appropriate
submenu and then pressing the Enter button. The Figure 2
shows a typical screen and navigation information.
Figure 2. Display layout.
The top section of the display indicates the section of the
menu system within which you are working. It will change
as you navigate through the menus. The lower portion of
the display indicates several pieces of information:
•
The Magnum PXR circuit breaker’s continuous current
rating is shown as In = XXXX on the left side.
•
A check mark will appear in the lower part of the display
as an indication of a received Zone Selective input signal.
See Section 3.9 - Zone selective interlocking (ZSI) for
more detail.
•
The lower right has a battery symbol indicating remaining
life of the battery.
