55
User Manual
MN013016EN
Effective July 2022
Magnum PXR and Power Defense SB low
voltage power circuit breakers user manual
EATON
www.eaton.com
Table 25. Contact opening
Problem
Possible root cause
Actions
Breaker will not open on expected
trip unit settings
Pinched or damaged wires
Repair damage
Damaged trip actuator (TA)
Contact Eaton Electrical Services & Systems
Broken TA tripper
Contact Eaton Electrical Services & Systems
Trip unit settings not as desired
Reset trip unit to proper settings
Trip unit not communicating correctly
Check communication devices and wiring
Breaker will not open by way of
accessories
Voltage at shunt trip too low
Excessive voltage drop in control wiring
Mis-wired open accessories
Correct secondary wire connections
Accessory not fully seated
Fully seat and lock accessory
Shunt trip cutoff switch not connected, present,
or damaged (instantaneous shunt trip only)
Connect, install, or replace shunt trip cutoff switch
Accessory deck broken or not locked down
Replace or lock down accessory deck
Other unidentified causes
Contact Eaton Electrical Services & Systems
Breaker will not open mechanically
Obstruction behind off pushbutton
Remove obstruction
Pushbutton cover blocking access to OPEN pushbutton
Remove cover.
Other unidentified causes
Contact Eaton Electrical Services & Systems
Table 26. Levering-in/-out (drawout applications only)
Problem
Possible root cause
Actions
Breaker will not rack in
Breaker does not push to stops evenly
Ensure breaker is square against stops by pushing evenly on both
sides of the breaker
Breaker/Cassette are equipped with mismatching rejection bracket
assemblies.
Ensure that rated current on the breaker matches the rated current
of the cassette. Check that cassette rejection bracket pin scheme
matches the cassette catalog number.
Attempting to rack in a breaker with PXR into a Digitrip cassette.
Replace cassette
Cassette floor pan mounting bolts in wrong location or
not low profile
Remove bolt and replace with low profile
Arc hood displaced and interfering with breaker movement
Replace arc hood
Cassette secondary sliding bracket not free to move with breaker
Remove wire obstruction or lubricate slide bushings and pin
Lev in device require re-lubrication
Lubricate lev in device
Excessive drive screw torque causing stripping or bending of
key components
Contact Eaton Electrical Services & Systems
Racking screw not in full retracted position before pushing breaker
into cell
Rotate to full counterclockwise stop
Breaker will not rack out
Other unidentified causes
Contact Eaton Electrical Services & Systems