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2. Trip unit description
Power XPert® release triP unit for MagnuM PXr circuit breakers
MN013015EN January 2022 www.eaton.com
Any time you change a switch position, the display will
temporarily change and indicate the values of all switches
to aid in configuring the correct settings. The menu system
also provides access to additional configuration options
beyond these core settings.
2.5 PXR 25 – Configure using the display
PXR 25 settings are configured using the display and menu
system. The same configuration options are present on both
the PXR 20 and PXR 25, but in the PXR 25 the PICKUP and
TIME settings can be fine-tuned to with smaller increments
between the minimum and maximum settings. Refer to
Section 1.3 - Primary protection features to understand the
flexibility in PXR 25.
The menu system provides access to each setting. From
the Main menu, press the Down arrow button until you get
to the Edit Settings field and then press the Enter button.
You will be asked for the password and, if entered correctly,
will be able to change the settings. You may also select View
Settings in the Main menu if you only want to understand
what settings have been configured.
2.6 Maintenance mode switch
When included on the PXR 20 or 25, the trip unit incor-
porates the Arc Flash Reduction Maintenance System™
(ARMS). This switch is labeled MAINT. MODE and has
two positions labeled: REMOTE & ON. A blue colored ring
surrounding the Maintenance Mode switch is illuminated
when ARMS is enabled.
•
ON
– ARMS is enabled locally and cannot be
disabled remotely.
•
REMOTE – ARMS is controlled remotely by a dry
contact or through communications. See Section 3.8 -
Maintenance mode.
2.7 Reset button
The button labeled RESET, located in the lower right of
the trip unit, can be depressed to reset the cause of trip
indicators.
2.8 Tamper proof cover
Controlling physical access is an important element in your
security policy. To support this, a clear plastic cover is
provided which allows the core current protection settings of
the PXR 20 to be viewed but not changed and to secure the
Maintenance Mode switch when desired. In the PXR 25 trip
unit, core current protection settings are protected using the
password features.
Unauthorized access to make changes can be prevented by
the insertion of a standard sealing wire through the security
holes to meet applicable tamper-proof requirements. Also
see section 3.1 - Password security as part of providing
tamper resistance.
2.9 Test and configuration port
Near the bottom of the PXR trip unit, there is a small door
with the Universal Serial Bus (USB) icon printed on it. The
door can be opened downward to expose the USB port utiliz-
ing a micro-B USB connection. This door can also be sealed
using standard sealing wire in conjunction with the clear
cover.
This USB connection is used in conjunction with the Power
Xpert Protection Manger (PXPM) software to configure and
monitor the trip unit. A USB connection will also provide
power from the host side of the USB cable to power up the
trip unit when another source of auxiliary power is not avail-
able. This connection is intended for temporary use while
you are configuring or monitoring the trip unit.
2.10 Battery
At the bottom of the frame module is a small tray which
holds the battery. When the trip unit is not powered, this
battery supports the Cause-of-Trip indicators (CoT) and Real-
time clock (RTC). When unpowered, the battery will support
the CoT and RTC for 20 days. The battery plays no part in
the protection functions of the trip system.
Status of the battery is displayed in the lower right corner of
the LCD and within PXPM.
On the initial installation of the circuit breaker, remove and
discard the insulating tab to enable the battery. Also press
the reset button to ensure the cause of trip LEDs are clear.
This battery is the standard lithium type CR 2032 coin-cell.
2.11 Breaker continuous current rating
On the lower right corner of the fame module is a label
which shows the circuit breaker’s continuous current.
2.12 Real-time clock
The trip unit contains a Real-time clock. The RTC is used as
the timestamp for all logged events. It is helpful, when diag-
nosing the circumstances of an event, to have it set to the
current date and time. The resolution is to the tenth (0.1) of
a second.
The clock should be set during commissioning (remember to
remove the battery insulating tab) to match a standard time
reference for your location. PXPM can be used to quickly
set the time, or the menu system via the front panel can
be used. We recommend that you periodically check and
correct the time should it experience drift during operation.
The Power Xpert Gateway (PXG 900) and Power Xpert
Dashboard (PXDB) can be used to periodically update the
RTC on all trip units connected to it. Alternately, the clock
can be set by a client via Modbus RTU.
