WCM6 Moulded case circuit breaker
WCM6 is one of updated type MCCBs researched and developed by the company by using advanced design and manufacture technology internationally.
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WCM6 series MCB is one of updated type MCCBs researched and developed by the company by using advanced design and manufacture technology internationally.
WCM6 is one of updated type MCCBs researched and developed by the company by using advanced design and manufacture technology internationally.

WCM6 sereis moulded case circuit breaker (MCCB for short) is the new type of product with top current limiting principal and manufacture technology in design, is tight in structure, total molularized, high breaking capacity, zero flashover. It applies at AC50Hz, rated operation voltage 690V and below, rated operation current upto 1250A for infrequent switch of line and infrequent start of motor. MCCB has overload, short circuit and under voltage protection device, to protect line and power evice from demage.

| Pole | 3P,4P |
| Voltage | AC400V |
| kA | 22KA-50KA |
| In(A) | 16-600A |
| Item No. | In(A) | Ue(V) | Ui(V) | Uimp(kV) | Frequency(Hz) | Cat | Ics(kA) | Icu(kA) |
| WCM6-100S/3300 | 100 | AC 400 | 1000 | 8 | 50 | B | 22 | 35 |
| WCM6-250S/3300 | 250 | AC 400 | 1000 | 8 | 50 | B | 25 | 50 |
| WCM6-400S/3300 | 400 | AC 400 | 1000 | 12 | 50 | B | 35 | 50 |
| WCM6-630S/3300 | 600 | AC 400 | 1000 | 12 | 50 | B | 35 | 50 |



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Related reading.
An MCCB is a low-voltage overcurrent protective device housed in a moulded thermoplastic case. It combines overload protection and short-circuit protection in a single enclosure, typically rated from 16A up to 1600A and breaking capacities from 10kA to over 100kA. Unlike a miniature circuit breaker (MCB), an MCCB offers higher current ratings, field-adjustable settings, and the option to add shunt trips, auxiliary contacts, and motor operators.
The breaking (interrupting) capacity, expressed in kA, is the maximum prospective short-circuit current the breaker can safely clear without damage. A 22kA–50kA MCCB can withstand and clear fault currents ranging from 22 kiloamperes to 50 kiloamperes rms. You must select a rating at least as high as the calculated maximum short-circuit current at the point of installation; exceeding it can result in breaker destruction and arc flash.
"4P" indicates a four-pole breaker that switches all four conductors of a three-phase four-wire system: L1, L2, L3, and the neutral. In 4P construction, the neutral pole can be either a fully switching pole (ON/OFF together) or a neutral pole that opens slightly later/earlier for selectivity reasons. A 4P MCCB is required for three-phase loads where galvanic isolation of the neutral is needed, such as in IT systems or main incomers.
CE marking indicates that the product conforms to applicable European Union directives (including the Low Voltage Directive and EMC Directive), allowing it to be sold throughout the EEA. CCC (China Compulsory Certification) is the mandatory safety mark required for products sold in China. Having both marks means the breaker has been independently tested to meet both European and Chinese safety standards, making it suitable for export and domestic Chinese projects.
An MCB (miniature circuit breaker) is typically rated up to 125A with fixed trip curves and lower breaking capacity (up to ~10kA), used for final small-load circuits. An MCCB handles much higher currents (up to 1600A), offers adjustable trip settings, higher breaking capacity (22kA–50kA or more), and more accessory options. In short: MCBs protect small branch circuits, while MCCBs protect feeders, mains, motors, and larger loads.
An ACB (air circuit breaker, also called a drawout or air circuit breaker) is typically rated from 630A up to 6300A, housed in an open air-insulated cubicle, and used as the main incomer or bus-tie in large switchgear. An MCCB is smaller, fixed-mount, and used downstream of the ACB for feeders and large branches. In a typical installation, an ACB sits at the main switchboard and MCCBs protect outgoing feeders.
This MCCB is widely used in industrial distribution panels, motor control centers (MCCs), building main switchboards, commercial building risers, transformer secondary feeds, and large branch circuits supplying three-phase machinery, HVAC, and UPS systems. Its 4-pole configuration makes it suitable for balanced three-phase loads and installations requiring neutral isolation.
Yes. The MCCB is manufactured and type-tested to IEC 60947-2, which defines requirements for low-voltage circuit-breakers including rated insulation voltage (Ui), rated impulse withstand voltage (Uimp), trip characteristics, and short-circuit performance (Icu ultimate and Ics service short-circuit breaking capacity). This guarantees predictable coordination with other protective devices in the installation.
The MCCB clips onto a standard DIN rail or bolts directly to the panel mounting plate via its fixing lugs. It is wired with copper busbars or appropriately sized cable lugs tightened to the manufacturer's torque value, with supply connected to the line terminals (marked "IN") and load to the load terminals ("OUT"). Adequate clearance above and below the breaker must be maintained for arcing during fault interruption, and the panel must be properly grounded.
Common field-installable accessories include auxiliary contacts (AL/AX) for remote status indication, shunt releases (SH) for remote tripping, undervoltage releases (UVR), motor operators (MCH) for remote closing, and terminal shields. These accessories allow the MCCB to be integrated into building automation, energy management, and emergency shutdown systems.
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