Circuit Breakers

Part Number	Description / PDF	Quantity
1D10UL Altech Corporation	CIR BRKR THRM-MAG 10A LEVER	0
3D20UM Altech Corporation	CIR BRKR THRM-MAG 30A LEVER	12316
MMS-32H-40A Altech Corporation	MANUAL MOTOR START 30KA 28-40A	2
1DU10R Altech Corporation	1DU10R10A MCB D CHAR 1P277VACUL1	108
GFL2C200302 Altech Corporation	MCCB+EGFP 20A240V AC 30MA C TRIP	47
2DU20L Altech Corporation	CIR BRKR THRM-MAG 20A LEVER	24
1C5UR Altech Corporation	1C5UR 5A MCB C CHAR 1 P 277VAC U	30
1D10UM Altech Corporation	CIR BRKR THRM-MAG 10A LEVER	40
2C10UL Altech Corporation	CIR BRKR THRM-MAG 10A LEVER	26
3BU32R Altech Corporation	3BU32R32AMCBBCHAR3P 480Y/277VACU	28
2DU40L Altech Corporation	CIR BRKR THRM-MAG 40A LEVER	2342
1BU3R Altech Corporation	CIR BRKR THRM-MAG 3A LEVER	39360
1CU3L Altech Corporation	CIR BRKR THRM-MAG 3A LEVER	31288
2DU25L Altech Corporation	CIR BRKR THRM-MAG 25A LEVER	136
GFR2B06100 Altech Corporation	EGFP+OL 6A277V AC 100MA B TRIP 1	0
GFL2C10010S Altech Corporation	MCCB+EGFP 10A120240V AC 10MA C T	6
2CU10R Altech Corporation	2CU10R 10A MCBCCHAR2P 480Y/277VA	18
GFR4D40100 Altech Corporation	EGFP+OL 40A480Y277V AC 100MA D T	0
GFR4D15030 Altech Corporation	EGFP+OL 15A480Y277V AC 30MA D TR	2
GFL2D06100S Altech Corporation	MCCB+EGFP 6A120240V AC 100MA D T	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