Electrical 400A AC Molded Case Circuit Breaker

Technical Specifications of Electrical 400A AC MCCB

• Rated Current (In): 400A
• Rated Operational Voltage (Ue): AC 400V / 415V
• Rated Insulation Voltage (Ui): Up to AC 800V
• Rated Frequency: 50 / 60 Hz
• Number of Poles: 3P / 4P optional
• Breaking Capacity (Icu): 50kA – 65kA (IEC 60947-2)
• Rated Service Breaking Capacity (Ics): 75% – 100% of Icu
• Trip Unit Type: Thermal-Magnetic / Electronic (optional)
• Trip Characteristics: Adjustable overload and fixed/adjustable short-circuit protection
• Mechanical Life: ≥ 10,000 operations
• Electrical Life: ≥ 20,000 operations
• Contact Material: Silver-tin oxide alloy
• Installation Method: Fixed mounting
• Connection Type: Front / Rear connection optional
• Operating Mechanism: Manual operation with optional motorized mechanism
• Protection Level: IP20 (higher with enclosure)
• Ambient Temperature: -5°C to +40°C
• Standards Compliance: IEC 60947-2, ISO9001

Product Features：

√ Breaking capacity reaches 65 kA

√ 400 A operational current rating

√ Contacts made of low-impedance silver alloy

√ High-speed four-bar linkage system

√ Compact construction, straightforward installation

√ Passes strict loop resistance verification

√ Automated manufacturing maintains uniformity

√ Immediate short-circuit interruption

√ Dependable downstream circuit safeguarding

√ Cost-efficient with reduced maintenance needs

Key Advantages of 400A AC MCCB

High Current Handling:

• Rated at 400A to manage heavy loads in large electrical systems
• Supports reliable operation of main panels and downstream equipment

Adjustable Trip Settings:

• Thermal-magnetic trip unit allows fine adjustment for overload and short circuit protection
• Optimizes protection based on load type and application scenario

High Breaking Capacity:

• Ultimate breaking capacity (Icu) of 50–65 kA per IEC 60947-2 standards
• Rapidly interrupts severe fault currents to protect equipment and cables

Compact Design:

• Space-saving solution compared to traditional frame circuit breakers
• Easy to install and maintain in panel boards and power distribution units

Versatile Accessories:

• Optional auxiliary contacts, shunt trips, and alarm modules for system integration
• Compatible with various control and monitoring setups

Durability and Reliability:

• Silver-tin oxide alloy contacts with precision stamping and laser welding
• Electrical life exceeding 20,000 cycles and low contact resistance under 35 micro-ohms
• Advanced assembly and calibration ensure consistent operating force and performance

Enhanced Safety:

• High-permeability silicon steel magnetic yoke ensures sub-10ms short-circuit trip response
• 100% factory inspection with torque-calibrated terminal screws and loop resistance verification
• Reliable protection against electrical faults and enhanced personnel safety

FAQ

What is the main application of a 400A MCCB?

• The Electrical 400A AC Molded Case Circuit Breaker is used in main power distribution panels for industrial, commercial, and large residential systems.
• Protects circuits from overloads, short circuits, and fault currents.
• Ensures reliable operation of downstream equipment like motors, transformers, and large appliances.

Is the 400A trip setting adjustable?

• Yes, the MCCB features a thermal-magnetic trip unit with adjustable settings.
• Allows customization based on load type and safety requirements.
• Helps prevent nuisance tripping while maintaining effective protection.

What is the difference between 3P and 4P 400A MCCBs?

• 3P MCCB: Protects three-phase circuits, leaving the neutral line unbroken.
• 4P MCCB: Protects three-phase circuits plus the neutral line, offering complete disconnection.
• Selection depends on system requirements and safety standards.

What cable size should I use for a 400A MCCB?

• Cable size depends on installation type, insulation material, and allowable voltage drop.
• Typically, 400A MCCBs are paired with cables ranging from 120 mm² to 185 mm² copper conductors.
• Consult Pugao Electric for precise recommendations based on specific project conditions.

How often should a 400A MCCB be tested?

• Periodic inspection is recommended, usually every 6–12 months for critical systems.
• Test for mechanical operation, trip response, and connection integrity.
• Ensures the Electrical 400A AC Molded Case Circuit Breaker maintains reliable protection throughout its service life.