MCCB Breakers

Updated: May 2026 · CNC Electric Pakistan

MCCB vs MCB — When to Step Up

An MCB (Miniature Circuit Breaker) tops out at 125 A with a breaking capacity of typically 6-10 kA. Beyond that, you need an MCCB. The transition matters because:

How to Size an MCCB — 3-Step Method

Step 1 — Calculate Total Load Current

For 3-phase 400 V system: I (A) = Total Power (kW) × 1000 ÷ (1.732 × 400 × 0.85) where 0.85 is typical power factor.

Step 2 — Apply 1.25× Safety Margin

Pick the next-higher standard MCCB rating above (load amps × 1.25). For 50 kW load: 85 A × 1.25 = 106 A → choose 125 A MCCB.

Step 3 — Verify Breaking Capacity (kA)

kA needed depends on distance from transformer and transformer kVA:

• 25-36 kA — adequate for most commercial use beyond 50 m from transformer
• 50 kA — required within 50 m of 200 kVA+ transformer (factories with own transformer)
• 65-100 kA — utility-side / large industrial / paralleled generators

MCCB Frequently Asked Questions — Pakistan

Q1: What is the price of a MCCB in Pakistan?

CNC MCCB prices in 2026 start at Rs. 1,200 for a 3P 25A 36 kA (small commercial) and go up to Rs. 35,000 for 4P 800A 65 kA (heavy industrial). The most common size for Pakistani 3-phase house mains (25 kVA) is 4P 63A at Rs. 2,800.

Q2: What is the difference between MCB and MCCB?

MCB handles up to 125 A with 6-10 kA breaking capacity (homes, lighting, sockets). MCCB handles 15-1600 A with 25-100 kA breaking capacity (sub-mains, factories, motors). MCCB has adjustable trip settings on 100A+ models; MCB is fixed.

Q3: Is CNC MCCB PSQCA approved?

Yes. All CNC YCM1 series MCCBs carry IEC 60947-2 compliance and PSQCA approval. Certification details are on the side label.

Q4: How do I size an MCCB for my factory?

Add up kW load → convert to amps (kW × 1.5 for 3-phase 400V) → multiply by 1.25 safety margin → choose next standard rating. Always verify breaking capacity matches your fault current level (typically 36 kA for most Pakistani sites; 50 kA near transformers).

Q5: Can I use a 4-pole MCCB on a single-phase circuit?

Yes but wasteful. Use 2-pole MCCB for single-phase 230V. Use 4-pole only for 3-phase with neutral switching (Pakistani TN-S systems).

Q6: What does the trip curve label mean (LSI, MA, etc.)?

MA = magnetic-only (for motor protection — no thermal). LSI = adjustable Long-time + Short-time + Instantaneous trip (commercial/industrial). For most general use, the standard thermal-magnetic version is correct.

Q7: What warranty does CNC offer on MCCBs?

1-year manufacturer warranty on electrical and mechanical defects. Claims processed at CNC service centre, College Road, Township, Lahore within 7 working days.

Ensure the safety and efficiency of your electrical installations with the CNC Electric MCCB Breaker, designed to provide superior protection against overloads, short circuits, and high current faults. CNC MCCBs are engineered for industrial, commercial, and residential distribution panels, delivering long-lasting performance and peace of mind in Pakistan’s electrical environments.

With a high-quality moulded case design and precise tripping mechanism, these breakers protect critical electrical equipment, prevent downtime, and ensure safe power distribution in 3-phase and single-phase systems. CNC MCCB Breakers are the trusted choice for electricians, panel builders, and industrial technicians who demand reliable, durable, and efficient electrical protection.

Key Features

• Heavy-Duty Protection: Safeguards against overload, short circuit, and phase imbalance
• Durable Moulded Case: Fire-resistant, heat-resistant, and impact-proof construction
• Reliable Trip Unit: Accurate and fast response to electrical faults
• Versatile Application: Compatible with single-phase & 3-phase panels
• Long Service Life: CNC’s trusted engineering ensures consistent performance
• Easy Installation: Standard mounting for DB boxes, MCC panels, and distribution boards
• Industrial-Grade Quality: Perfect for factories, workshops, commercial buildings, and residential power systems

Why Choose CNC MCCB Breaker?

CNC Electric is recognized in Pakistan for premium electrical protection solutions. Their MCCB Breakers help prevent:

• Electrical short circuits
• Overload damage
• Fire hazards and equipment burnouts
• Downtime in industrial and commercial systems

CNC MCCBs ensure safe, organized, and stable power distribution, making them ideal for professional installations and high-load systems.

Applications

• Industrial Machines & MCC Panels
• Commercial Buildings & Offices
• DB Boxes & Main Distribution Panels
• Solar Inverter & Hybrid Systems
• Workshops, Factories, and Warehouses
• HVAC & Motor Control Systems

Frequently Asked Questions