Circuit Breakers

Part Number	Description / PDF	Quantity
2907602 Phoenix Contact	CIR BRKR 40A 240VAC 125VDC	330
0902153 Phoenix Contact	CIR BRKR THRM-MAG 63A 277VAC	6
0912052 Phoenix Contact	CIR BRKR 12A 24VDC AUTO RESET	0
1019990 Phoenix Contact	CIRCUIT BRAKER 50A	1453
2907628 Phoenix Contact	CIR BRKR THRMMAG 3A 277VAC 60VDC	50
0902425 Phoenix Contact	CIR BRKR THRM-MAG 32A 480VAC	3
0914455 Phoenix Contact	CIR BRKR THRMMAG 2A 250VAC 65VDC	134
2800849 Phoenix Contact	CIR BRKR THRMMAG 3A 277VAC 50VDC	1471
1019987 Phoenix Contact	CIRCUIT BRAKER 30A	7156
1019909 Phoenix Contact	CIRCUIT BREAKER 2A	0
1135749 Phoenix Contact	SINGLE-CHANNEL, ELECTRONIC FUSE	20
1020023 Phoenix Contact	CIRCUIT BRAKER 10A	2186
1020078 Phoenix Contact	CIRCUIT BRAKER 40A	14
2909902 Phoenix Contact	SINGLE-CHANNEL ELECTRONIC CIRCUI	0
5650106 Phoenix Contact	CIR BRKR 500MA 250VAC 80VDC	174
2800874 Phoenix Contact	CIR BRKR THRMMAG 6A 277VAC 80VDC	12
0900812 Phoenix Contact	CIR BRKR 8A 24VDC AUTO RESET	0
2800863 Phoenix Contact	CIR BRKR THRMMAG 6A 277VAC 50VDC	53
2907613 Phoenix Contact	CIR BRKR 7A 480VAC 125VDC	6
2800879 Phoenix Contact	CIR BRKR 500MA 277VAC 80VDC	1

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