The Live CA350B Triple Pole MCB is a heavy-duty miniature circuit breaker engineered to serve as a main isolation and protection device for large commercial and light industrial electrical installations. Rated at 50 Amps with a B-curve tripping characteristic, this 3-pole breaker operates reliably on AC systems up to 400V at 50/60Hz frequency. It delivers robust protection against overloads and short circuits, making it the ideal choice for main distribution boards, large commercial complexes, and high-capacity resistive loads. With a formidable 6kA breaking capacity and precision-engineered thermo-magnetic release, the CA350B ensures safety, reliability, and long-term performance for mission-critical electrical infrastructure.

Key Features of Live CA350B 50A MCB

• High-Current B-Curve Protection: Trips instantaneously at 3-5 times the rated current (150A to 250A), specifically calibrated for high-power resistive loads and main distribution applications.

• Main Distribution Capability: 50A rating per pole makes it ideal for main switch applications in large commercial establishments, small factories, and high-capacity sub-distribution boards.

• Commercial Infrastructure Protection: Perfect for protecting circuits in large restaurants, community halls, schools, small industrial units, and multi-story residential buildings.

• Substantial Breaking Capacity: Certified 6kA rating ensures safe interruption of high fault currents, protecting expensive downstream equipment and wiring infrastructure.

• Precision Thermo-Magnetic Release: Combines thermal bimetal strip for accurate time-delayed overload protection and magnetic solenoid for instantaneous short-circuit response.

• Superior Electrical Isolation: With 4000V impulse withstand rating and 500V insulation voltage, providing excellent protection against voltage transients and power surges.

• Extended Operational Life: Engineered for 8,000 electrical operations, ensuring decades of reliable service in commercial applications with regular switching requirements.

• Professional Installation: Standard DIN-rail mounting with IP20 finger-safe terminals and 16mm² wiring capacity for secure commercial panel integration.

Technical Specifications

Frequently Asked Questions (FAQs)

1. What are the primary applications for the Live CA350B 50A B-Curve MCB?
The CA350B is specifically designed for main distribution and high-power resistive loads. Ideal applications include:

• Main switch/isolation for large commercial sub-distribution boards

• Large community halls and auditorium electrical mains

• School and college building sub-mains

• Small factory and workshop distribution boards

• Large commercial kitchen complexes

• Electric vehicle charging station infrastructure

• High-capacity water heating systems for hotels and hostels

• Large-scale LED signage and exterior lighting installations

2. What is the maximum power capacity of this 50A 3-phase MCB?
For a standard 400V three-phase system, the CA350B can handle approximately:

• Maximum resistive load: P = √3 × V × I = 1.732 × 400V × 50A = 34.64 kW

• For continuous operation (80% rule): Maximum continuous load should not exceed 40A per phase, which equates to approximately 27.71 kW continuous resistive load.

• This makes it suitable as a main breaker for medium-sized commercial establishments, small factories, and large residential complexes.

3. Why is the CA350B 50A B-Curve ideal for main distribution applications?
As a main switch, the B-Curve characteristic provides several advantages:

• Faster fault clearance: Responds more quickly to short-circuit conditions (3-5x In), limiting potential damage and arc flash energy

• Better coordination: Provides excellent discrimination with downstream C-Curve breakers protecting motor circuits

• Simpler fault diagnosis: Makes it easier to identify whether faults originate in the main distribution versus branch circuits

• Suitable for mixed loads: When the predominant loads are resistive (lighting, heating, general power), B-Curve offers optimal protection
  The 50A rating provides sufficient capacity for most small to medium commercial establishments while maintaining coordination with downstream protection devices.

4. Can this 50A MCB be used as a main breaker for a small industrial unit?
Yes, the Live CA350B is well-suited as a main isolation and protection device for small industrial units, workshops, and light manufacturing facilities. However, careful consideration should be given to the load composition:

• If predominantly resistive loads: (lighting, heating, office areas) - Excellent choice

• If significant motor loads present: Ensure proper coordination with downstream C-Curve breakers

• If large motors start simultaneously: Consider potential cumulative inrush currents

• If in doubt about load characteristics: Consult with a qualified electrical engineer for proper coordination study

5. What are the cable sizing requirements for a 50A main breaker installation?
For a 50A MCB in commercial or industrial applications, proper cable sizing is critical for safety and compliance:

• Minimum copper conductor: 10 mm² for very short runs in ideal conditions

• Recommended copper conductor: 16 mm² for standard installations (maximizes terminal capacity)

• For longer runs (over 25 meters): Consider 25 mm² cable (requires external termination as breaker accepts only 16mm²)

• Voltage drop consideration: For 50A loads over distance, voltage drop calculations may require larger conductors
  Important notes:

• The CA350B terminals accept cables up to 16 mm² maximum

• For larger cables, use a separate terminal enclosure or distribution block

• Always consider insulation type (PVC, XLPE), installation method (conduit, tray, direct burial), and ambient temperature

• Consult IEC 60364 or local electrical regulations for definitive requirements

• Consider using parallel cables if higher capacity is needed while maintaining terminal compatibility