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9 Maintenance of the trip unit
PXR tRiP units foR PoweR Defense molDeD case ciRcuit bReakeRs
MN012007EN March 2019 www.eaton.com
9 Maintenance of the trip unit
Minimal maintenance is required. Keep the clear plastic cover in place regardless of if you lock it or not to help keep the
front of the unit clear of dirt. Do not insert any foreign objects into the USB port; this may damage the connector’s contacts.
Do not subject the trip unit to any harsh chemicals or gasses to preserve the original look and feel of the unit.
9.1 Replacing the battery
The battery is provided in certain PXR styles to maintain the LED indication of the cause-of-trip. A battery icon at the bottom
of the display indicates remaining battery life. The battery plays no part in the protection function of the trip system. The
battery can be replaced at any time, even while the circuit breaker is in-service, without affecting the operation of the circuit
breaker or its protection functions.
The 3 V lithium battery, type CR1216 (“coin-cell”), is easily removed and replaced; pull to remove the battery tray, remove
the old battery from the holder, replace with new one (observe proper polarity as marked on the tray), and then re-insert the
battery tray into the slot on the trip unit. In the PD2, remove the cover above the handle and pockets using a small screw-
driver to access the battery. Accidentally installing the battery in the reverse direction will not harm the battery or the trip
unit, but will defeat the function of the battery.
9.2 Replacing the ETU
Although not typically needed, certain styles of the PXR trip unit can be changed in the field to add features. The Instruction
Leaflet for each trip unit includes instructions for possible replacement and/or addition of features.
10 Available protection settings
Available settings for any circuit breaker are a function of the frame and trip unit. Please consult the following information to
help identify the frame, trip unit and available settings.
10.1 Identifying the trip unit
The catalog numbers for circuit breakers that include the PXR trip units use the following schema:
