Circuit Breakers

Part Number	Description / PDF	Quantity
GFR2D16300 Altech Corporation	EGFP+OL 16A277V AC 300MA D TRIP	0
US-14 Altech Corporation	SURGE UNIT VARISTOR 380 440VACDC	0
GFR4D30300 Altech Corporation	EGFP+OL 30A480Y277V AC 300MA D T	0
2G12UM Altech Corporation	2G12UM 12A CIRCUIT BREAKER G CHA	12
3Z03UM Altech Corporation	3Z03UM 0.3A CIRCUIT BREAKER Z CH	0
1D32UR Altech Corporation	1D32UR 32A MCB D CHAR 1 P 277VAC	12
3Z12UM Altech Corporation	3Z12UM 12A CIRCUIT BREAKER Z CHA	0
1D15DL Altech Corporation	1D15DL 15A CIRCUIT BREAKER D CHA	0
3D40UR Altech Corporation	3D40UR 40A MCB D CHAR 3 P 480Y/2	0
3BU10R Altech Corporation	3BU10R10AMCBBCHAR3P 480Y/277VACU	16
2C2.5UM Altech Corporation	2C2.5UM 2.5A CIRCUIT BREAKER C C	0
3DU5R Altech Corporation	3DU5R 5AMCBDCHAR3P 480Y/277VACUL	68
3CU5R Altech Corporation	3CU5R5AMCBCCHAR3P 480Y/277VACUL1	116
UV48DCR Altech Corporation	CIRCUIT BREAK UNDERVOLT 48V DC C	0
TR11-C-X-63-B-1-C-1.0A Altech Corporation	CIRCUIT BREAK TPBDVERMAHEX METNU	0
GFR2C16010 Altech Corporation	EGFP+OL 16A277V AC 10MA C TRIP 1	0
GFR4D32030 Altech Corporation	EGFP+OL 32A480Y277V AC 30MA D TR	0
GFR4D05030 Altech Corporation	EGFP+OL 5A480Y277V AC 30MA D TRI	0
3E075UM Altech Corporation	3E075UM 0.75ACIRCUIT BREAKER ECH	0
2B4UR Altech Corporation	2B4UR 4A MCB B CHAR 2 P 480Y/277	24

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