Circuit Breakers

Part Number	Description / PDF	Quantity
GFR4C08030 Altech Corporation	EGFP+OL 8A480Y277V AC 30MA C TRI	0
1D4UR Altech Corporation	1D4UR 4A MCB D CHAR 1 P 277VAC U	0
GFR2B08300 Altech Corporation	EGFP+OL 8A277V AC 300MA B TRIP 1	0
GFL2B25100SN Altech Corporation	MCCB+EGFP 25A120240V AC 100MA B	0
1ZU5L Altech Corporation	1ZU5L5A MCB Z CHAR 1P277VACUL489	0
2D50DL Altech Corporation	2D50DL 50A CIRCUIT BREAKER D CHA	0
1DU12L Altech Corporation	1DU12L 12A MCB D CHAR 1P277VACUL	0
3D5UL Altech Corporation	3D5UL 5A CIRCUIT BREAKER D CHAR3	52
3BU60R Altech Corporation	3BU60R60AMCBBCHAR3P 480Y/277VACU	0
2DU25R Altech Corporation	2DU25R25A MCBDCHAR2P 480Y/277VAC	108
3B13UM Altech Corporation	CIRCUIT BREAKER 13A B 3P 277V UL	0
GFL2B16300SN Altech Corporation	MCCB+EGFP 16A120240V AC 300MA B	0
2Z30UL Altech Corporation	2Z30UL 30A CIRCUIT BREAKER Z CHA	0
GFL2C30300S Altech Corporation	MCCB+EGFP 30A120240V AC 300MA C	6
2D03DL Altech Corporation	2D03DL 0.3A CIRCUIT BREAKER D CH	0
MA025UM Altech Corporation	MA025UM 016-025A 3P MOTORPROTECT	0
GFL2C080302 Altech Corporation	MCCB+EGFP 8A240V AC 30MA C TRIP	18
GFL2D13030SN Altech Corporation	MCCB+EGFP 13A120240V AC 30MA D T	0
2Z03UM Altech Corporation	2Z03UM 0.3A CIRCUIT BREAKER Z CH	0
2C13UR Altech Corporation	2C13UR 13A MCB C CHAR 2 P 480Y/2	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