MCCB Breaker for Distribution Boards and Circuit Protection
An MCCB breaker protects electrical distribution circuits and cables against overloads and short circuits within its specified ratings and protection settings. Typical applications include main and sub-main distribution boards and feeders serving commercial, residential, and industrial installations.
UniStream supplies molded case circuit breakers based on project requirements. Specify the rated current, operating voltage, number of poles, breaking capacity, trip unit, and preferred brand when requesting a quote.
What Does MCCB Stand For?
MCCB stands for Molded Case Circuit Breaker. Its insulating enclosure houses the switching mechanism and protection components. Selection depends on the circuit design, connected load, and prospective fault current at the installation point.
Available Order Options
| Parameter | Available Options |
|---|---|
| Product type | Molded Case Circuit Breaker (MCCB) |
| Rated current | 100A / 160A / 200A / 250A / 300A / 400A, or other specifications by enquiry |
| Operating voltage | 380V / 450V, or other specifications by enquiry |
| Poles (shown as Phase in the product options) | 1P / 2P / 3P / 4P, subject to series availability |
| Trip settings | Fixed / Adjustable, depending on the model |
| Trip unit | Thermal-magnetic / Electronic |
| Short-circuit breaking capacity | Specified in kA at the operating voltage, depending on the model |
| Brand selections | Schneider Electric / ABB / Siemens / LS Electric / Eaton / M.E.T / Al-Fanar, subject to availability |
Available combinations vary by manufacturer and series. Confirm the exact model and ratings against the manufacturer’s datasheet and the quotation.
Fixed vs Adjustable MCCB Breakers
Fixed Trip Settings
Fixed-trip models have factory-defined protection settings. They suit circuits whose protection requirements match the breaker’s specified tripping characteristics.
Adjustable Trip Settings
Selected models allow adjustment of specific protection settings, such as pickup current, short-circuit thresholds, or time delays. The available adjustments depend on the trip unit and product series.
Thermal-Magnetic and Electronic Trip Units
- Thermal-magnetic: Combines thermal overload protection with magnetic short-circuit protection.
- Electronic: Uses current sensing and electronic protection functions. Adjustment options and additional functions depend on the model.
Check the trip unit’s datasheet if your project requires ground-fault protection, metering, or communication.
Typical Applications
- Main distribution boards (MDBs).
- Sub-main distribution boards (SMDBs).
- Commercial and residential electrical feeders.
- Industrial distribution systems and workshop supplies.
- HVAC equipment and chiller feeders.
- Motor and pump feeders, with application-specific protection where required.
- Generator distribution circuits, according to the approved electrical design.
Difference Between MCB and MCCB
Both types provide overload and short-circuit protection. MCBs commonly serve final circuits, while MCCBs are commonly used for distribution and larger feeders. Current ratings, breaking capacities, and trip characteristics vary by series. Some MCCB models offer adjustable trip settings.
Compare the circuit requirements with the breaker’s technical data before specifying a model. Amperage is one of several selection criteria.
How to Select an MCCB Circuit Breaker
- Rated current: Match the load, cable capacity, and protection requirements.
- Operating voltage: Check the breaker’s rating at the system voltage.
- Poles (Phase selector): Specify the number of poles required by the circuit design.
- Icu and Ics: Review the breaking-capacity ratings at the operating voltage against the prospective fault current.
- Trip unit: Specify thermal-magnetic or electronic protection.
- Protection settings: Identify the functions and adjustments required.
- Coordination: Review coordination with upstream and downstream protective devices.
- Installation dimensions: Confirm panel fit, terminals, and connection arrangements.
MCCB Breaker FAQs
Are all MCCBs adjustable?
No. Some models have fixed settings. Others allow adjustment of specific functions, depending on the trip unit.
Is amperage enough to specify a breaker?
No. Include the operating voltage, number of poles, breaking capacity, and trip requirements. Provide the model number if you have it.
Does every MCCB provide earth-leakage protection?
No. If your project requires earth-leakage protection, check whether the selected breaker includes that function or requires a separate earth-leakage protection device.
Can I request a current or voltage rating not listed?
Yes. Select Custom in the relevant current or voltage field and add the product to your quote cart. Enter the required rating in the notes when reviewing the cart so UniStream can check availability.
Request an MCCB Breaker Quote
Provide the rated current, operating voltage, number of poles, breaking capacity, trip unit, preferred brand, and quantity, then request a quote for an MCCB breaker from UniStream. Attach your specification schedule or model number if available.
