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)