Circuit Breakers

Part Number	Description / PDF	Quantity
2907692 Phoenix Contact	CIR BRKR 32A 480VAC 125VDC	30
0903025 Phoenix Contact	CIR BRKR SOLID STATE 3A 24VDC	9252
3000766 Phoenix Contact	CIR BRKR SOLID STATE 10A 12VDC	21
1020052 Phoenix Contact	CIRCUIT BRAKER 20A	16
2907629 Phoenix Contact	CIR BRKR THRMMAG 4A 277VAC 60VDC	34
0914853 Phoenix Contact	CIR BRKR THRMMAG 5A 250VAC 65VDC	0
5650122 Phoenix Contact	CIR BRKR 12A 250VAC 80VDC	0
0903043 Phoenix Contact	CIR BRKR SOLID STATE 2A 24VDC	12
2907557 Phoenix Contact	CIR BRKR 32A 480VAC 125VDC	21
2907205 Phoenix Contact	CIR BRKR MAG-HYDR 10A 120AC/50DC	16
2907642 Phoenix Contact	CIR BRKR 30A 277VAC 60VDC	7108
2907575 Phoenix Contact	CIR BRKR 30A 277VAC 60VDC	111
0700010 Phoenix Contact	CIR BRKR THRM 10A 32VDC	59
2907512 Phoenix Contact	CIR BRKR 12A 480VAC 125VDC	36
2907653 Phoenix Contact	CIR BRKR 3A 480VAC 125VDC	45
2907539 Phoenix Contact	CIR BRKR 1A 480VAC 125VDC	34
0902205 Phoenix Contact	CIR BRKR THRMMAG 4A 277VAC LEVER	1
2907532 Phoenix Contact	CIR BRKR 32A 480VAC 125VDC	57
2907626 Phoenix Contact	CIR BRKR THRMMAG 1A 277VAC 60VDC	27202
2907630 Phoenix Contact	CIR BRKR THRMMAG 5A 277VAC 60VDC	269

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