Circuit Breakers

Part Number	Description / PDF	Quantity
4420.0361 Schurter	CIR BRKR THRM MAG 30A 360 VDC	0
GMB631PC5 Carlo Gavazzi	CIR BRK THRM-MAG 5A 240VAC/60VDC	23
2907564 Phoenix Contact	CIR BRKR 7A 277VAC 60VDC	972
W57-XB1A4A10-10 TE Connectivity Potter & Brumfield Relays	CIR BRKR THRM 10A 250VAC	662
R21-1-20.0A-G182IV-V Sensata Technologies – Airpax	CIR BRKR MAG-HYDR 20A ROCKER	25
4430.2356 Schurter	CIR BRKR THRM 15A 240VAC 60VDC	19
2C6UL Altech Corporation	CIR BRKR THRM-MAG 6A LEVER	86
4230-T130-K0CE-40A E-T-A	CIR BRKR THERM 40A 480VAC/125VDC	0
4230-T120-K0CU-1A E-T-A	CIR BRK THERM-M 1A 480VAC/125VDC	3
9926251007 Weidmuller	CIR BRKR MAG-HYDR 7A 120VAC	19
2907602 Phoenix Contact	CIR BRKR 40A 240VAC 125VDC	330
1BU10R Altech Corporation	CIR BRKR THRM-MAG 10A LEVER	4884
4230-T120-K0DU-32A E-T-A	CIR BRKR THERM 32A 480VAC/125VDC	0
GMS-32H 1A Carlo Gavazzi	MMS 32A HIGH BREAK 0.63-1A	0
4400.0751 Schurter	CIR BRKR THRM 15A 240VAC 48VDC	0
BR2D40UC Weidmuller	CB MCB 489 2P D 40A ACDC	888
ACBM-PX-8A OptiFuse	MAXI FUSE FOOTPRINT-TYPE I, 8A	0
9926253520 Weidmuller	CIR BRKR MAG-HYDR 20A 480VAC	0
4230-T130-K0BU-60A E-T-A	CIR BRKR THERM 60A 480VAC/125VDC	0
IULK1-38559-20 Sensata Technologies – Airpax	CIRCUIT BREAKER MAG-HYDR LEVER	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