Circuit Breakers

Part Number	Description / PDF	Quantity
4420.0225 Schurter	CIR BRKR THRM MAG 16A 480V 65V	0
4400.0549 Schurter	CIR BRKR THRM 3.3A 240VAC 48VDC	0
4430.1273 Schurter	CIR BRKR THRM 1A 240VAC 60VDC	209
TS-709-8 Schurter	CIR BRKR THRM 8A 250VAC 50VDC	226
4430.2014 Schurter	CIR BRKR THRM 16A 240VAC 60VDC	14
4410.9012 Schurter	CIR BRKR THRM 16A 240VAC 28VDC	28
4435.0267 Schurter	CIR BRKR THRM 5A 240VAC 60VDC	0
4411.0073 Schurter	CIR BRKR THRM 25A 277VAC 28VDC	19
4435.0233 Schurter	CIR BRKR THRM 6A 240VAC ROCKER	14
4435.0571 Schurter	CIR BRKR THRM 3A 240VAC 32VDC	56
4435.0103 Schurter	CIR BRKR THRM 5A 240VAC 32VDC	9
4430.1855 Schurter	CIR BRKR THRM 8.5A 240VAC 60VDC	11
4430.2196 Schurter	CIR BRKR THRM 20A 240VAC 60VDC	231300
4435.0625 Schurter	CIR BRKR THRM 4A 240VAC 32VDC	19
4404.0059 Schurter	CIR BRKR THRM 10A 240VAC 48VDC	0
4400.0735 Schurter	CIR BRKR THRM 50MA 240VAC 48VDC	0
4430.1813 Schurter	CIR BRKR THRM 240VAC 60VDC	0
4430.1365 Schurter	CIR BRKR THRM 2A 240VAC 60VDC	0
4430.2053 Schurter	CIR BRKR THRM 16A 240VAC 60VDC	0
4430.071 Schurter	CIR BRKR THRM 16A 240VAC 60VDC	0

Circuit Breakers

1. Overview

Circuit breakers are automatic electrical switches designed to protect circuits from damage caused by overloads or short circuits. Unlike fuses, they can be reset after tripping. Modern circuit breakers ensure electrical safety, prevent equipment damage, and maintain system reliability in residential, commercial, and industrial applications.

2. Main Types and Functional Classification

Type	Function Features	Application Examples
MCB (Miniature Circuit Breaker)	Thermal-magnetic protection, <100A rating	Residential wiring, lighting circuits
MCCB (Molded Case Circuit Breaker)	Adjustable trip settings, 10-2500A rating	Industrial machinery, HVAC systems
ACB (Air Circuit Breaker)	High fault current interruption, 400-6300A rating	Power distribution in data centers
RCCB (Residual Current Circuit Breaker)	Earth leakage protection (5-500mA sensitivity)	Outdoor outlets, swimming pool equipment
RCBO (Residual Current Breaker with Overcurrent)	Combines overload, short-circuit, and leakage protection	Hospital equipment, construction sites

3. Structure and Components

Typical components include: - Enclosure: Flame-retardant insulating material housing - Contacts: Silver alloy for high conductivity - Trip Mechanism: Bimetallic strip (thermal) and electromagnetic coil (magnetic) - Arc Extinguisher: Multi-plate chamber for arc suppression - Operating Lever: Manual ON/OFF control with position indicators

4. Key Technical Parameters

Parameter	Description	Importance
Rated Current (In)	Maximum continuous current without tripping	Determines load capacity
Rated Voltage (Un)	Maximum operating voltage	Ensures insulation safety
Breaking Capacity (Icu)	Maximum fault current interrupting capability	Prevents catastrophic failure
Tripping Characteristics	Time-current curve (B/C/D types)	Matches load requirements
Pole Number	1P to 4P configurations	Determines phase protection

5. Application Fields

Power distribution: Residential panels, commercial switchboards
Industrial equipment: Motors, transformers, CNC machines
Renewable energy: Solar inverters, wind turbine systems
Transportation: EV charging stations, rail traction systems

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
Schneider Electric	Acti 9 series	Modular design, 0.5-125A range
Siemens	5SJ series	High short-circuit withstand, DIN rail mount
ABB	Emax series	Smart connectivity, up to 6300A
General Electric	THQL series	UL-certified, industrial motor protection

7. Selection Guidelines

Key considerations: - Match rated current to load requirements (125% safety margin) - Select tripping curve (Type B for resistive loads, C for motors) - Verify breaking capacity against system fault levels - Consider environmental factors (temperature, altitude) - Ensure compliance with standards (IEC 60898, UL 489) - Example: For a 20kW motor (400V), select MCCB with 63A rating, Type C curve, 50kA breaking capacity

8. Industry Trends

Emerging trends include: - Smart grid integration with IoT-enabled monitoring - Compact designs for space-constrained applications - Eco-friendly materials with halogen-free construction - Integration with renewable energy systems - Predictive maintenance via AI-powered diagnostics - Increased adoption of DC circuit breakers for EV infrastructure