WESTINGHOUSE E-Series MCCB (Molded Case Circuit Breaker)

WESTINGHOUSE E-Series MCCB (Molded Case Circuit Breaker)

Product Overview and Brand Background

Brand foundation: As a globally renowned brand with a 130 year history of product innovation, Westinghouse's business covers areas such as home appliances, consumer electronics, power generation and distribution equipment, with reliability and innovation as its core advantages.

Product positioning: The E-series molded case circuit breaker (MCCB) is the core product in its power transmission and distribution field, designed specifically for industrial and civilian power distribution systems. Its core function is to achieve overload protection and short circuit protection of the circuit, ensuring the safety of electrical equipment and lines.

Core standard: The product fully complies with the IEC 60947-2 international standard, has passed CE certification, has stable performance, and has extensive compatibility.

Overview of Product Core Technical Parameters

（1） Basic electrical parameters

Rated current range: 16-800A, divided into two series based on frame size: EJ (100-250A) and EK (320-630A), covering all scenarios from low to medium high current.

Rated voltage and frequency: Operating voltage of 240/415V AC, suitable for mainstream civil and industrial distribution voltages worldwide; Frequency 50/60Hz, strong universality.

Insulation and impulse withstand: The maximum insulation voltage (Ui) is 1000V, and the impulse withstand voltage (Uimp) is 8-12kV (8kV for EJ frame and 12kV for EK frame). The insulation performance is excellent, avoiding leakage and voltage impulse damage.

Short circuit breaking capacity (Icu/Ics): There are four levels: 25kA, 36kA, 50kA, and 85kA. The highest breaking capacity is 85kA in the 220-240V AC scenario and 50kA in the 380-415V AC scenario, which can quickly cut off different levels of short circuit faults and prevent circuit fires.

Calibration temperature: 55 ℃, rated current and protection characteristics are calibrated based on this temperature, suitable for industrial high-temperature operating environments.

（2） Physical and installation parameters

Pole configuration: The entire series supports two configurations: 3 poles and 4 poles. 3 poles are suitable for three-phase power distribution (such as motors and industrial equipment), and 4 poles are suitable for scenarios with neutral line protection (such as civil buildings and hybrid distribution systems).

Wiring specifications: Cable cross-section 25-300mm ² (EJ frame 25-185mm ², EK frame 35-300mm ²), both incoming (Line) and outgoing (Load) lines support cable wiring to meet different current carrying requirements.

Size and weight:

EJ frame (100-250A): 3 poles (165 × 105 × 77mm, 1.5kg), 4 poles (140 × 185 × 77mm, 2.0kg), compact size, suitable for small distribution boxes.

EK frame (320-630A): 3-pole (257 × 140 × 111.7mm, 5.7kg), 4-pole (257 × 185 × 111.7mm, 7.5kg), structurally stable, suitable for industrial distribution cabinets.

Product series segmentation and detailed model explanation

The E series is divided into sub series based on frame size, short-circuit breaking capacity, and trip type. Each sub series includes a 3/4 pole model and corresponds to a unique reference number for easy selection and procurement. The specific breakdown is as follows:

（1） EJ framework (rated current 100-250A)

Suitable for low and medium current scenarios, compact in size, with a breaking capacity covering 25-50kA, including automatic and non automatic operation. The details of the sub series are as follows:

Subseries Short Circuit Breaking Capacity, Tripping Type, Core Characteristics, Rated Current Specification, 3P Reference Number Example, 4P Reference Number Example

EIJ 25kA fixed thermal magnetic trip (F) with fixed thermal magnetic trip parameters, easy to operate, and cost-effective  100A、125A、160A、200A、250A EIJ3100F（W605836） EIJ4100F（W605841）

EIJ 25kA adjustable thermal magnetic release (TM) thermal release 0.8-1.0In, magnetic release 5-10In, flexible adaptation  100A、125A、160A、200A、250A EIJ3100TM（W605846） EIJ4100TM（W605851）

ESJ 36kA adjustable thermal magnetic trip (TM) has improved breaking capacity and is suitable for medium short circuit risk scenarios  100A、125A、160A、200A、250A ESJ3100TM（W605856） ESJ4100TM（W605861）

EHJ 50kA adjustable thermal magnetic release (TM) high breaking capacity, suitable for high short circuit risk scenarios such as industrial equipment  100A、125A、160A、200A、250A EHJ3100TM（W605866） EHJ4100TM（W605871）

EIJY - Non Automatic - No automatic trip function, only manual control of on/off, suitable for special control scenarios  100A、125A、160A、200A、250A EIJY3100（W605876） EIJY4100（W605881）

（2） EK frame (rated current 320-630A)

Suitable for medium and high current scenarios, with a breaking capacity of 36-50kA. Some models support electronic tripping, with higher adjustment accuracy. The details of the sub series are as follows:

Subseries Short Circuit Breaking Capacity, Tripping Type, Core Characteristics, Rated Current Specification, 3P Reference Number Example, 4P Reference Number Example

ESK 36kA fixed thermal magnetic release (F) with fixed parameters, suitable for general industrial distribution, high cost-effectiveness  320A、400A、500A、630A ESK3320F（W605886） ESK4500F（W605904）

ESK 36kA Adjustable Thermal Magnetic Release (TM) Thermal Release 0.8-1.0In, Magnetic Release 5-10In, Flexible Adaptation  320A、400A、500A、630A ESK3320TM（W605890） ESK4630TM（W605909）

ESK 36kA Electronic Release (E) Electronic Adjustment, High Accuracy, Stable Protection Characteristics 500A, 630A ESK3500E (W607452) ESK4630E (W610439)

EHK 50kA Adjustable Thermal Magnetic Release (TM) High Breaking Capacity+Adjustable Parameters, Suitable for Large Equipment Power Distribution  320A、400A、500A、630A EHK3320TM（W605894） EHK4630TM（W605913）

EHK 50kA electronic release (E) high breaking and high-precision electronic release, suitable for precision industrial systems  500A、630A EHK3500E（W607454） EHK4630E（W610441）

ESKY - Non Automatic Manual Control, No Automatic Protection, Suitable for Special Control Scenarios  320A、400A、500A、630A ESKY3320（W605898） ESKY4630（W605917）

Types and protection characteristics of trip units

The trip unit is the core of the circuit breaker, responsible for detecting circuit abnormalities and triggering tripping. The E series provides three types of trips to meet different precision and scenario requirements, and the protection characteristics are clearly defined by the time current curve:

（1） Detailed explanation of types of trip units

Fixed Thermal&Magnetic Release

Working principle: The thermal trip element (bimetallic strip) detects overload current, slowly heats up and deforms to trigger tripping (delayed protection); Magnetic release element (electromagnet) detects short-circuit current and instantly generates suction force to trigger tripping (instantaneous protection).

Advantages: Simple structure, high reliability, low cost, no need for power supply, suitable for general scenarios without special adjustment requirements for paired protection parameters.

Adjustable Thermal&Magnetic Release

Adjustment range: Thermal trip (overload protection) 0.8-1.0In, the overload threshold can be fine tuned according to the circuit load characteristics; Magnetic release (short-circuit protection) 5-10In, adaptable to different short-circuit current levels.

Advantages: Strong universality, able to flexibly match different load types (such as motors, lighting, power equipment), and is the main release type of the E series.

Electronic Adjustable Release

Core features: By detecting current through electronic components, the adjustment accuracy is higher (with an error of ± 2%), and the protection characteristics can be subdivided (such as long delay, short delay, instantaneous), only available in EK frame 500-630A models.

Advantages: More comprehensive protection functions, suitable for precision equipment and industrial automation systems with high protection accuracy requirements.

（2） Time current curve characteristics

Circuit breakers of different current levels have clear time current curves to ensure the accuracy and coordination of protection actions:

EJ framework 200-250A (ESJ, EHJ series):

Overload protection (delay): When the rated current is 1.3 times, the tripping time is about 10-30 minutes; When the rated current is 4 times, the tripping time is about 2-6 minutes.

Short circuit protection (instantaneous): maximum instantaneous tripping current 2500 ± 500A, total breaking time ≤ 0.05 seconds.

EK framework 315-400A (ESK, EHK series):

Overload protection (delay): When the rated current is 1.3 times, the tripping time is about 14-30 minutes; When the rated current is 6 times, the tripping time is about 4-10 minutes.

Short circuit protection (instantaneous): instantaneous tripping current 6-10In (± 20%), total breaking time ≤ 0.05 seconds.

EK frame 500-630A (ESK, EHK series):

Overload protection (delay): When the rated current is 1.3 times, the tripping time is about 14-30 minutes; When the rated current is 6 times, the tripping time is about 4-10 minutes.

Short circuit protection (instantaneous): instantaneous tripping current 6-10In (± 20%), total breaking time ≤ 0.05 seconds.

Optional attachments and extended features

The E series supports multiple accessory extensions, which can be flexibly matched according to control and monitoring needs to enhance the functionality and adaptability of circuit breakers

Shunt Trip: Receive external control signals (such as fire linkage and remote commands) to achieve remote tripping and adapt to scenarios that require centralized control.

Under Voltage: When the circuit voltage is lower than the set value, it automatically trips to protect voltage sensitive equipment (such as precision instruments and motors).

Aux. Contacts: Used to provide feedback on the on/off status of circuit breakers (such as "closed" and "tripped" signals), compatible with automated monitoring systems.

Trip Alarm Contacts: When the circuit breaker trips due to overload or short circuit, an alarm signal is issued to facilitate troubleshooting and maintenance.

Application scenarios and selection suggestions

（1） Core application areas

In the field of industrial production: power distribution protection for factory workshops, industrial plants, and production lines, overload and short circuit protection for equipment such as motors, pumps, and fans. The EK frame 320-630A series is recommended (EHK sub series is preferred, with high breaking capacity more suitable for industrial scenarios).

In the field of commercial architecture: power distribution systems for shopping centers, office buildings, and hotels, suitable for lighting, air conditioning, elevators, and other equipment. We recommend the EJ frame 100-250A series (ESJ sub series, balancing reliability and compactness).

In the field of civil architecture, the EJ framework 100-250A series (EIJ sub series, cost-effective, and easy to operate) is recommended for the protection of distribution boxes in residential communities and apartment buildings, as well as for household electricity and public lighting.

Special scenario: For equipment that requires manual control of on/off (such as testing equipment, temporary power distribution), non automatic models (EIJY, ESKY series) are recommended; Precision equipment and automation systems, recommended electronic release models (ESK-E, EHK-E series).

（2） Key points of selection

Current matching: Select the rated current based on the maximum operating current of the circuit, with a 20% margin reserved (such as selecting a 250A rated current model for a maximum operating current of 200A).

Breaking capacity matching: Select breaking capacity based on the short-circuit current level of the distribution system. For industrial scenarios with high short-circuit currents, priority should be given to models with breaking capacity of 36kA or higher.

Selection of release type: Fixed/adjustable thermal magnetic release is selected for general scenarios, and electronic release is selected for precision equipment.

Pole selection: Choose 3 poles for three-phase power distribution and 4 poles for mixed distribution with neutral wire.

Attachment configuration: Remote control is required to select shunt release, voltage sensitive equipment to select undervoltage release, and automation monitoring to select auxiliary contacts and alarm contacts.