Circuit Breakers

Part Number	Description / PDF	Quantity
3120-F321-P7T1-W02D-10A E-T-A	CIR BRKR THRM 10A 250VAC 50VDC	18
IULK11-1REC4-61-5.00-A-01 Sensata Technologies – Airpax	CIR BRKR MAG-HYDR 5A LEVER	0
R21-2-5.00A-B162IV-V Sensata Technologies – Airpax	CIR BRKR MAG-HYDR 5A ROCKER	0
1410-G111-P2F1-S01-2A E-T-A	CIR BRKR THRM 2A 250VAC 50VDC	0
4230-T110-K0BE-2A E-T-A	CIR BRK THRM-MAG 2A 277VAC/60VDC	0
4435.0015 Schurter	CIR BRKR THRM 2A 240VAC ROCKER	3
4430.3749 Schurter	CIR BRKR THRM 10A 240VAC 60VDC	15
1410-L210-L2F1-S02-10A E-T-A	CIR BRKR THRM 10A 250VAC 50VDC	1247
1170-21-3A E-T-A	CIRCUIT BREAKER THRM 3A 28VDC	2
4430.1158 Schurter	CIR BRKR THRM 240VAC 60VDC	15
6720005301 Weidmuller	CIR BRKR THRM 1A 24VDC SLD SWCH	3239
4430.2115 Schurter	CIR BRKR THRM 20A 240VAC 60VDC	437180
J7MC-3R-E25 Omron Automation & Safety Services	CIR BRKR MAG 250MA 690VAC ROTARY	0
GMB63H2PC8 Carlo Gavazzi	CIR BRKR THERM-MAG 8A 480/277V	4
R21-2REF..S00376396 Sensata Technologies – Airpax	CIRCUIT BREAKER MAG-HYDR ROCKER	0
6720005304 Weidmuller	CIR BRKR THRM 4A 24VDC SLD SWCH	3503
4230-T120-K0DE-3A E-T-A	CIR BRK THERM-M 3A 480VAC/125VDC	0
3DU10L Altech Corporation	CIR BRKR THRM-MAG 10A LEVER	752
4400.0526 Schurter	CIR BRKR THRM 1A 240VAC 48VDC	0
0914853 Phoenix Contact	CIR BRKR THRMMAG 5A 250VAC 65VDC	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