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Maintenance, testing, and operating conditions
MAGNUM PXR PRODUCT GUIDE
PA013006EN September 2022 www.eaton.com
6
Figure 82. Diagnostics menu with operations
sub-menu
All these parameters are saved in the nonvolatile memory
of the PXR trip unit. The data may be retrieved locally or
remotely via control or communication systems for further
analysis and data recording that drive improved operating
efficiency to keep downtime to a minimum.
Testing
Periodic testing is important to ensure proper functionality
of the breaker and trip unit. In addition to secondary injec-
tion testing for the trip unit and internal breaker sensors
as described in
Section 4
(Secondary injection testing via
PXPM), primary injection testing can also be performed
to test the tripping system functionality. The PXR manual,
MN13015EN, provides guidance on primary injection
ground fault testing.
Other field testing may include a primary circuit resistance
test using a digital low resistance ohmmeter (DLRO) or
a millivolt-meter. Instantaneous primary injection testing
should be performed prior to the resistance check, and
the breaker should be operated several times to allow the
contact wiping action under rated current to remove the
buildup of corrosion on the contacts through the opening
process. Use a 24 Vdc or less direct current power supply
capable of supplying at least 100A, and do not maintain
current for more than 1 minute. A reading that increases
by a factor of two and is over 100 microOhms is consid-
ered a concern.
In addition to breaker testing, questions may arise on how
to handle the breakers when testing the assemblies they
are installed in, mainly when performing high potential
(hi-pot) or dielectric testing. No components in the breaker
or trip unit need to be disconnected when performing a
hi-pot test. This includes the voltage divider board used
with PXR 25 trip units. Refer to the switchgear manufac-
turer for additional guidance on assembly testing.
Tools for troubleshooting
Event summaries
Eaton’s Power Xpert Protection Manager (PXPM) software
provides trip and alarm event summaries. The summaries
capture details about the event that occurred including
primary and secondary status, cause of status, tempera-
ture at the time of event, and current on all three phases.
Additional information about the event can be found on
the Event Detail View Panel on the PXPM software (
Figure
83
). The trip unit can store up to 200 summaries and 10
trips or 10 alarm events. More detailed information will be
stored for those 10 trip and alarm events.
Figure 83. Event detail view panel on the PXPM
software
Waveform capture
In addition to on-demand waveform recording, PXPM
also provides access to waveform capture. Waveform
capture stores the waveforms associated with the last
trip the breaker experienced. When an event occurs, the
trip unit will begin storing 6 pre-trip waveform cycles. The
trip unit will continue to record the event and 4 cycles
post-event (auxiliary voltage is required to record any
post-trip waveform cycles). This information can be used
to analyze system performance or damage after a trip
event. A license through PXPM is required to view these
waveforms.
Figure 84. Waveform capture screen on the PXPM
software
