Eaton Plastic Case Circuit Breaker Technology Analysis and Application Guide

Eaton Plastic Case Circuit Breaker Technology Analysis and Application Guide

Introduction: The Industry Status of Molded Case Circuit Breakers and Eaton's Innovative Inheritance

Since the introduction of circuit breakers in the 1920s, molded case circuit breakers (MCCBs) have been indispensable protective components in low-voltage distribution systems. As a global leader in the field of power management, Eaton Corporation provides the most comprehensive line of molded case circuit breakers for the electrical industry with its profound technological accumulation and continuous innovation. From the classic Series C and Series G to the latest generation Power Defense series, Eaton constantly breaks through technological boundaries and integrates safety, reliability, and intelligence into every circuit breaker.

This article is based on Eaton's official product catalog CA08100005E (January 2026 edition), providing an in-depth analysis of the technical highlights of the Power Defense series. It also outlines the specifications and applications of Series G, Series C, and various special circuit breakers, offering a professional and detailed technical guide for electrical engineers, system integrators, and project decision-makers.

Chapter 1: Power Defense Series: The Benchmark for the Next Generation of Molded Case Circuit Breakers

1.1 Product positioning and core advantages

Power Defense is Eaton's flagship molded case circuit breaker product line launched for the global market, covering a current range of 15A to 2500A, and can be equipped with thermal magnetic or electronic release devices. Its design goal directly targets the intelligent power distribution demand in the Industry 4.0 era and has the following significant advantages:

Global certification: Simultaneously meets UL 489, CSA C22.2 No.5, IEC 60947-2, GB 14048.2 and other standards, suitable for North American, European and Asian markets.

Modular design: All accessories (auxiliary switches, alarm switches, shunt release, undervoltage release, etc.) are field installable, greatly reducing inventory costs and on-site modification difficulties.

Communication capability: Built in communication interface, can be connected to PLC, building management system or cloud platform to achieve remote monitoring and data collection.

Security Enhancement: Integrated with Eaton's patented Arcflash Reduction Maintenance System ™ (Arc Flash Reduction Maintenance System) significantly reduces the arc flashover energy during maintenance, ensuring personnel safety.

1.2 Power Xpert Release (PXR) Electronic Release Unit

The core innovation of the Power Defense series lies in the installation of PXR series electronic release units, which are divided into three levels:

PXR 10

Positioning: Basic electronic release, suitable for applications that are cost sensitive but still require electronic protection.

Protection function: LSI protection (long delay, short delay, instantaneous) can be set through panel dialing.

Applicable framework: PD-2 to PD-6.

PXR 20

Positioning: A versatile electronic release that adds richer protection and measurement functions.

Enhanced features:

Current measurement and display

Programmable relay output

Optional embedded Modbus communication

Support Zone Selective Interlocking, ZSI）

Built in Arcflash Reduction Maintenance System

Fault type indication

Applicable framework: PD-2 to PD-6.

PXR 25

Positioning: Top intelligent release device with power quality monitoring and advanced communication capabilities.

Unique features:

The accuracy of electric energy measurement reaches ± 1%

Supports multiple protocols such as Modbus TCP, PROFIBUS, etc. (requires communication adapter module CAM)

Built in 3 programmable relays

Real time assessment of the health status of circuit breakers (internal temperature, number of operations, fault level, etc.)

Event recording (up to 200 events)

Applicable framework: PD-3 to PD-6.

1.3 Framework Dimensions and Selection Guidelines

The Power Defense series has 6 frame sizes, each corresponding to a specific current range and release options:

Frame current range, release type, pole number, characteristic

PD-1 15-125 A thermal magnetic (fixed) 1-4P compact, optional current limiting type

PD-2 15-225 A Thermal Magnetic/PXR 10/20 1-4P Standard Type, Optional Ground Fault Protection

PD-3 45-600 A Thermomagnetic/PXR 10/20/25 2-4P divided into 400A/600A two structures, optional 100% rated

PD-4 300-800 A thermal magnetic/PXR 10/20/25 2-4P 800A frame, supporting 100% rated

PD-5 320-1200 A PXR 20/25 2-4P expandable to 1600A (IEC), supports 100% rated

PD-6 700-2500 A PXR 20/25 2-4P maximum 2500A, supports 100% rated

1.4 Breaking capacity and electrical parameters

The breaking capability of Power Defense covers a wide range from basic industrial to high demand applications. Taking PD-2 as an example, its breaking capacity at 240 Vac can be selected from 25kA to 200kA (corresponding to design codes F, G, K, M, N, P). It is worth noting that some models in the PD-2 series have UL current limiting capabilities (such as N and P types), which can significantly reduce the impact of fault currents on downstream equipment.

In terms of DC applications, the Power Defense framework supports DC distribution of 250 Vdc and below, and can achieve higher voltage through series connection of poles (such as PD-3/PD-4, which can reach 800 Vdc through 4-pole series connection).

1.5 Modular Attachment System

The accessory system of Power Defense is highly unified, and the same accessory can be used across multiple frameworks, greatly simplifying on-site configuration and inventory management.

Instruction attachment (right cavity)

Auxiliary switch: configured with 1NO+1NC (Form C) or 2NO+2NC, used for remote indication of circuit breaker status.

Alarm switch: It operates when the circuit breaker trips due to a fault, and automatically resets after manual reset.

Release attachment (left cavity)

Split release: Remote control circuit breaker tripping, suitable for emergency disconnection or interlocking systems.

Undervoltage release: When the voltage drops to 35%~70% of the rated value, the circuit breaker trips to prevent undervoltage operation.

All attachments provide various wiring methods such as 30 inch (0.75m) or 118 inch (3m) fly wires, screw terminals, spring clip terminals, etc.

1.6 Communication and Software Ecology

Power Defense is not only a protective device, but also a node of intelligent distribution network. PXR 20/25 supports accessing the following networks through CAM (Communication Adapter Module):

Modbus TCP/IP（ECAM）

PROFIBUS DP（PCAM）

With Eaton's Power Xpert Protection Manager (PXPM) software, users can:

Online modification of protection settings

Perform secondary injection testing

View real-time energy data

Analyze event waveform

Generate test report

Chapter 2 Series G and Series C: Inheritance and Transition of Classic Series

2.1 Series G: Compact Design for Global Use

Series G is Eaton's molded case circuit breaker series launched for the global market, represented by "G" for Global. Its core advantages lie in:

Compact size: reduces installation space by an average of 35% compared to traditional circuit breakers.

Universal attachments: Frame attachments below 630A are universal, simplifying selection.

Electronic release: Equipped with Digittrip RMS 310+, it has functions such as true effective value measurement, curve tuning, and thermal memory.

Current range: EG (15-125A), NG (320-1200A), RG (800-2500A).

NG and RG frameworks can be equipped with LSI, LSIG, ALSI and other models of Digitrip RMS 310+. Among them, the ALSI model has a built-in Arcflash Reduction Maintenance System, which can be activated by remote signals to reduce the instantaneous setting value to 2.5 times the rated current, effectively reducing arc flashover energy.

2.2 Series C: A classic that is about to be delisted

Series C is Eaton's classic product line, covering 15A to 2500A, including multiple frames such as G, F, J, K, L, and M. According to the catalog, multiple frameworks of Series C are scheduled to be delisted in 2026, but complete replacement support will still be provided. Its typical characteristics include:

Thermal magnetic trip and electronic trip: such as FD series thermal magnetic circuit breakers, with a maximum breaking capacity of 200kA (480V); The FDCE series electronic release supports LSI/LSIG.

Motor protection dedicated: HMCP series motor circuit protector, designed specifically for use with contactors, can provide instantaneous overcurrent protection from 3A to 1200A.

DC application: HFDDC, HJDDC and other DC specific models can meet the protection requirements of 125V to 750V DC systems.

2.3 Special Circuit Breaker

2.3.1 DC Circuit Breaker

Suitable for UPS, photovoltaic, electric vehicle charging and other scenarios, with a maximum voltage of 800Vdc and a maximum current of 3000A (RGHDC frame). High voltage breaking is achieved through series connection of poles, such as the 800Vdc four pole series connection scheme of PD-3/PD-4.

2.3.2 PVGard Photovoltaic Circuit Breaker

Specially designed for photovoltaic systems, meeting UL 489B standards and capable of reliable operation in ambient temperatures ranging from -40 ° C to+90 ° C. The 1000Vdc four pole series model provides a breaking capacity of 3kA to 7.5kA, supports bidirectional current, and is suitable for series protection.

2.3.3 E2 Mining Circuit Breaker

Meets MSHA 30 CFR 75 specifications and is designed specifically for harsh environments such as coal mines. Using electronic release, the instantaneous setting value strictly meets the protection requirements of the towing cable, and the breaking capacity can reach up to 1200V 10kA. The E2 series provides comprehensive coverage from E2F (15-150A) to E2R (1600-2000A).

Chapter 3 Attachments and Extended Functions

3.1 Types of Wiring Terminals

Power Defense offers multiple terminal options to accommodate different wiring needs:

Standard terminal: made of steel or aluminum material, suitable for copper or aluminum wires.

Multi wire terminal: allows one pole to connect multiple wires (such as 3 or 6), replacing the distribution terminal block.

StrandAble terminal: designed specifically for thin twisted wires to ensure reliable connection.

Rear wiring terminal: used for rear wiring and needs to be used in conjunction with a partition.

3.2 Operating mechanism and locking device

Rotating handle: direct, variable depth, metal variable depth, suitable for different cabinet depths, with padlock function.

Flexible shaft handle: capable of remote operation between circuit breakers and doors, with a maximum length of 10 feet.

Interlocking device: including sliding rod interlocking and rocker arm interlocking, used for mechanical interlocking between two circuit breakers to prevent simultaneous closing.

Padlock device: The handle can be locked in the ON or OFF position to meet the safety padlock requirements.

3.3 Special Environmental Applications

High temperature environment: Thermal magnetic circuit breakers need to be used with reduced capacity above 40 ° C. Electronic release devices are not sensitive to ambient temperature, but they will trip automatically when the internal overheating occurs.

High altitude: For every distance exceeding 1000m (>2000m), the voltage/breaking capacity needs to be reduced by 2.5%, and the ambient temperature should be adjusted according to 3 ° C/1000m.

400Hz application: Due to skin effect, reduced capacity is required for use, and the cable cross-section needs to be increased compared to 60Hz.

Chapter 4 Selection and Key Points of Engineering Application

4.1 Protection Function Selection

Thermomagnetic release: suitable for simple loads, low cost, but accuracy is affected by environmental temperature.

Electronic release: suitable for complex power distribution systems, with high protection accuracy, multiple adjustable parameters, and support for communication.

LSI: Long delay+Short delay+Instantaneous, suitable for feeder protection.

LSIG: Add ground fault protection, suitable for places sensitive to ground leakage (such as medical and data centers).

4.2 Selection of Rated Values

80% rated: For routine applications, the continuous load of the circuit breaker shall not exceed 80% of the rated value.

100% rated: requires the use of 90 ° C cables and reduced capacity to 75 ° C for use, and installed in the specified minimum size cabinet.

4.3 Selective Coordination

By utilizing the ZSI (Zone Selective Interlocking) function, it is possible to achieve rapid isolation of upstream and downstream circuit breakers in the event of a fault, while ensuring continuous power supply to non fault areas. The Power Defense PXR 20/25 supports ZSI and indicates interlock status through the front panel LED.

Power Defense series circuit breaker models

1. PD-1 framework (15-125 A)

Model Description

PDG13M0003MSAJ MCP 3A

PDG13M0007MSAJ MCP 7A

PDG13M0015MSAJ MCP 15A

PDG13M0030MSAJ MCP 30A

PDG13M0050MSAJ MCP 50A

PDG13M0070MSAJ MCP 70A

PDG13M0100MSAJ MCP 100A

PDG13M0100MHAJ MCP 100A (high setting)

2. PD-2 framework (15-225 A)

Model Description

PDG23M0003MSAJ MCP 3A

PDG23M0007MSAJ MCP 7A

PDG23M0015MSAJ MCP 15A

PDG23M0030MSAJ MCP 30A

PDG23M0050MSAJ MCP 50A

PDG23M0100MSAJ MCP 100A

PDG23M0150MSAJ MCP 150A

PDG23M0150MHAJ MCP 150A (high setting)

3. PD-3 framework (45-600 A)

Model Description

PDG33M0070MSAJ MCP 70A (400A frame)

PDG33M0100MSAJ MCP 100A (400A framework)

PDG33M0125MSAJ MCP 125A (400A framework)

PDG33M0150MSAJ MCP 150A (400A framework)

PDG33M020MSAJ MCP 200A (400A framework)

PDG33M0225MSAJ MCP 225A (400A framework)

PDG33M0250MSAJ MCP 250A (400A framework)

PDG33M0300MSAJ MCP 300A (400A framework)

PDG33M0350MSAJ MCP 350A (400A framework)

PDG33M0400MSAJ MCP 400A (400A framework)

PDG33M0400MHAJ MCP 400A (high setting)

PDG33MH250MSAJ MCP 250A (600A framework)

PDG33MH300MSAJ MCP 300A (600A framework)

PDG33MH350MSAJ MCP 350A (600A framework)

PDG33MH400MSAJ MCP 400A (600A framework)

PDG33M0450MSAJ MCP 450A (600A framework)

PDG33M0500MSAJ MCP 500A (600A framework)

PDG33M0600MSAJ MCP 600A (600A framework)

4. Grounding fault module (30 mA)

Model Description

ELEBN3125G PD1 3P UL Grounding Fault Module

ELEBN4125G PD1 4P UL Grounding Fault Module

ELEBE3125G PD1 3P IEC leakage module

ELEBE4125G PD1 4P IEC leakage module

PDGXRCD3P225 PD2 3P UL grounding fault module 225A

PDGZXRCD4P225 PD2 4P UL Ground Fault Module 225A

PDG3XRCD3P400 PD3 3P UL grounding fault module 400A

PDG3XRCD4P400 PD3 4P UL Ground Fault Module 400A

PDG3XRCD3P600 PD3 3P UL grounding fault module 600A

PDG3XRCD4P600 PD3 4P UL Grounding Fault Module 600A

PDE3XRC3P630 PD3 3P IEC leakage module 630A

PDE3XRCD4P630 PD3 4P IEC leakage module 630A

PDC3XRC3P630 PD3 3P IEC/CC leakage module 630A

PDC3XRCD4P630 PD3 4P IEC/CC leakage module 630A

5. Current limiting module

Model Description

EGC3015FFGQ01 EG frame line side current limiting module

EGC3015FFGQ02 EG frame load side current limiting module

JGH3070FAGQ01 JG Frame Line Side Current Limiting Module

JGH3070FAGQ02 JG frame load side current limiting module

HMCPJ250D5LH01 HMCP 250A line side current limiting module

HMCPJ250D5LK02 HMCP 250A load side current limiting module

6. High instantaneous selective coordinated circuit breaker

Model Description

LHH3125FFG LHH 125A Thermomagnetic

LHH3150FFG LHH 150A Thermomagnetic

LHH3175FFG LHH 175A Thermomagnetic

LHH3200FFG LHH 200A Thermomagnetic

LHH3225FFG LHH 225A Thermomagnetic

LHH3250FFG LHH 250A Thermomagnetic

LHH3300FFG LHH 300A Thermomagnetic

LHH3350FFG LHH 350A Thermomagnetic

LHH3400FFG LHH 400A Thermomagnetic

NHH3150T52X15 NHH 150A LSI Electronics

NHH3175T52X15 NHH 175A LSI Electronics

NHH3200T52X15 NHH 200A LSI Electronics

NHH3225T52X15 NHH 225A LSI Electronics

NHH3250T52X15 NHH 250A LSI Electronics

NHH3300T52X15 NHH 300A LSI Electronics

NHH3350T52X15 NHH 350A LSI Electronics

PDJ53MH400P2DN PDJ5 400A PXR 25

PDJ53MH400PYN PDJ5 400A PXR 25

7. DC circuit breaker

Model Description

EGEDC3025FFG EGEDC 25A DC

EGSDC3025FFG EGSDC 25A DC

EGHDC3025FFG EGHDC 25A DC

HFDDC3015L HFDDC 15A DC

HJDDC3250F HJDDC 250A Framework

HKDDC3400F HKDDC 400A Framework

HLDDC3600F HLDDC 600A Framework

HLDDC20600 HLDDC 600A 2P

HMDLDC3800F HMDLDC 800A Framework

NBDC3700MW NBDC 700A DC

RGHDC3160FFWE RGHDC 1600A DC

8. PVGard Photovoltaic Circuit Breaker (1000 Vdc)

Model Description

FDPV4030W FD PV 30A 80% rated

CFDPV4030W FD PV 30A 100% rated

KDPV4125W KD PV 125A 80% rated

CKDPV4125W KD PV 125A 100% rated

LGPV4250W LG PV 250A 80% rated

CLGPV4250W LG PV 250A 100% rated

MDLPV3300W MDL PV 300A 80% rated

CMDLPV3300W MDL PV 300A 100% rated