24
User Manual
MN013016EN
Effective July 2022
Magnum PXR and Power Defense SB low
voltage power circuit breakers user manual
EATON
www.eaton.com
Table 4. Magnum PXR and PD-SB trip units
Trip unit
Trip unit
catalog number
Breaker catalog
digit 13,14
Protection
ARMS
Communication
Metering
PXR 20
PXR20VN30LNNC
2A
LSI
N
Adapter module (CAM)
Current
PXR20VN30LGNC
2C
LSIG
N
Adapter module (CAM)
Current
PXR20VN30LNAM
2H
LSI
Y
Modbus RTU & CAM
Current
PXR20VN30LGAM
2F
LSIG
Y
Modbus RTU & CAM
Current
PXR 25
PXR25VN30LNAM
2Q
LSI
Y
Modbus RTU & CAM
Current, voltage, power, energy
PXR25VN30LGAM
2S
LSIG
Y
Modbus RTU & CAM
Current, voltage, power, energy
Notes
LSI = Long, short and instantaneous protection are available
LSIG = Long, short, instantaneous, and ground protection are available
CAM = Communication adapter module, see Section 4.4 Communications adapter modules (CAMs).
The Trip Unit contains the electronics which support the protection
functions, metering capability, user interface and communication
features . It can be replaced in the field for the same style unit or
to a different style . Note that upgrading may require the installation
of other sub-system components and wiring to enable full feature
support .
The Frame Module is mounted permanently to the circuit breaker
frame, it should not be removed or replaced . It holds factory
configured frame information regarding the circuit breaker rating,
sensor calibration, and operation . The interface circuit for the sensors
as well as the configurable relays are mounted in the frame module .
The Voltage Module converts the line voltage from the top or
bottom breaker terminals for sensing by the trip unit electronics . It is
included on PXR 25 trip unit styles .
The electronic trip units are self-powered . When the circuit breaker
is closed, no external power is required to operate their current
protection systems . Current signal levels and the control power are
derived from the current sensors integrally mounted in the circuit
breaker .
The test functions are integrated into the trip unit and do not require
a separate test kit . Secondary injection is accomplished using an
on-board circuit to provide the input to the trip unit . Tests are initiated
using the trip unit’s front panel and by using the configuration
software, Power Xpert Protection Manager (PXPM) .
Four built-in test modes are available for use: functional test using
secondary injection, functional test using simulated current, current
sensor continuity test, and open breaker functional test . Complete
testing of the trip unit system can be accomplished when a current
sensor test is used in conjunction with secondary injection test .
When the circuit breaker is shipped from the factory, the trip
unit’s protective functions are normally set at minimum values .
For specific overload tripping characteristics and time/current
curves to coordinate with a load or system, refer to the trip unit
instruction book .
Figure 31. PXR 25 programmable trip unit installed in Magnum
PXR circuit breaker