izmx-S Air Circuit Breakers – 'Series NRX': Highest performance in a minimum of space Modern systems for low-voltage energy distribution, particularly those for regenerative applications, are more compact yet make higher demands on the integrated components.
The new 'Series NRX' meets these increased demands with new materials and a modified construction. Two compact sizes facilitate smaller switch panels. The modular design and common range of accessories allow simple integration. 'Series NRX' offers a high degree of functionality and communication capability with impressive performance.

See also: www.eaton.com/seriesnrx izmx Features
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  • Modern circuit-breaker technology reduces system costs
  • The high-end multi-functional control unit (P type) with large colour graphic display facilitates all well-known applications
  • Modbus, Profibus, Ethernet and INCOM compatible
  • Engineering design simplified by reduction to just 2 sizes
  • Flexible and easy connection using the rotating connection adapter and associated connection options

Main applications:

  • System protection
  • Motor protection
  • Transformer protection
  • Generator protection

With the selection of the appropriate control unit, the switches are optimised for these applications and include comprehensive additional functions as standard or as options.

false false Technical Overview
'Series NRX' IZMX16 IZMX40
Rated current in A 630 – 1600 A 800 – 4000 A
Rated voltage in V up to 690 V up to 690 V
Short-circuit breaking capacity Icu = Ics bei 440 V
42 kA X
50 kA X
65/66 kA X X
85 kA X
105 kA X
Number of poles 3/4 3/4
Dimensions in mm
Fixed installation
Width 210/279 430/545
Height 338 398
Depth 184 298
Withdrawable units
Width 254/324 425/540
Height 360 456
Depth 289 367
false false Accessories

With the comprehensive accessories of the “Series NRX” switches, the ACB can be adapted to individual demands.
The accessories have been specially developed for Plug&Work functionality. This focus is on simple installation in the field and a high level of availability.

The sizes IZMX16 and IZMX40 feature identical accessories in size-independent applications. It simplifies selection and enhances flexibility.

The following accessories are available:

  • Withdrawable units
  • Actuation
  • Voltage releases
  • Auxiliary and signalling switches
  • Interlocks
  • Control units
  • Communication
  • General accessories.
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Arms System for IZM ARMS System

Our circuit-breakers are optionally available with the new and patented ARMS System (Arcflash Reduction Maintenance System™). In the event of an arc fault, the trip unit breaks instantaneously and quickly.

Breaking is even faster than that of a non-delayed short-circuit trip. This function can be activated directly on the circuit-breaker or by an external switch, e.g. when maintenance staff enter a danger zone. A special wiring configuration is not required.

Diagram Arms System for IZM Zone selectivity ZSI

Now always on board and can be enabled.

Circuit breakers are directly connected to a signal line, without any additional modules. So, in case of short circuits, they ensure that only the circuit breaker immediately upstream the point of failure will break a short-circuit without delay.

The advantage of the zone selectivity feature – compared to ordinary time selectivity – is the significantly reduced delay time until tripping.

This reduces the thermal and dynamical load that protect the system in addition. In cases of a signal wire damage the back-up time selectivity ensures the selectivity of the system.

For additional safety of maintenance staff we recommend a combination with ARMS to reduce the released amount of energy even further.

System Diagnostics and Monitoring image
Power Xpert Release (PXR) with multiple new features


  • ● Trip cause LEDs 
  • ● Magnitude of trip information 
  • ● Remote signal contacts 
  • ● Programmable signalling contacts
  • ● Modbus on board for PXR25 (optional for PXR20)
  • ● Large LCD combined with cursor operation for more function and information
  • ● Battery status, ZSI and rated current visible anytime
  • ● ZSI – the better selective protection is always on board
  • ● Password protection
  • ● Rating plug programmable
  • ● LSI protection can be changed to LI (without time selectivity Tsd = 0) or LS (without Instantaneous II = 0 = 100% selective)
  • ● 3 free alarms contacts available
  • ● USB port for testing and additional function setup via PC and software PXPM

  • ● QR code for easier identification and further information

  • ● Improved Diagnostics with breaker health (graph), events and run time



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Increased operating safety and flexibility based on communication - image

Increased operating safety and flexibility based on communication.

Thanks to its ability to communicate, the IZMX circuit breaker series taps new opportunities for power distribution.

It provides all the information that is relevant for operation and forwards it.

This way the transparency of the system can be increased and response times to statuses such as overcurrent, phase imbalance and overvoltage can be reduced. By quickly intervening in a process, system standstills can be prevented or preventive maintenance actions can be planned.

Consequently, the availability of the system can be increased as well.

With the respective communication module – PCAM, MCAM or ECAM (Profibus-DP / Modbus / Ethernet Communications Adapter Module) – every circuit breaker of the IZMX series is equipped for modern communication and is fit for the future. The databus not only allows to transmit information, but also to receive commands/settings.

Onboard Modbus communication is standard on the PXR25 (P type) trip unit and optional on the PXR20 (V type) trip unit upon order. Additional PCAM, MCAM or ECAM module can be installed externally for PXR25 to expand the communication capability.

false Tools

Configuration Software for Circuit Breaker
The tool supports error-free product combination and ordering.


  • Easy operation
  • Fault-free selection and ordering of MCCB/ACB items


The xSpider software system is a graphically oriented design system for dimensioning of low-voltage networks fitted with Eaton brand circuit protection equipment.

  • All calculations are based on applicable IEC standards
  • Voltage drops, load distribution, short circuit currents, etc.
  • Selectivity: working with tripping characteristics and selectivity spread sheets (tested combinations)
  • ArcRISK module: evaluation of risks caused by Arc-Flash and efficient improvement by Eatons protective measures (internal separation, Diagnose, passive protection, ARMS™, ARCON®, etc.)
  • Generation of documentation and reports

CurveSelect simply visualizes, compares and documents characteristic curves. The assessment of the interaction of the circuit-breakers of the NZM and IZM series, motor-protective circuit-breakers PKZ and PKE, overload relay Z and miniature circuit-breakers as well as low-voltage high-breaking-capacity fuses is made significantly easier.


false Drawings Drawings in different formats can be found here. false Videos

false Documentation For more documentation please see here.

true Europe_Elec_File 979679285485 false