Circuit Breakers

Part Number	Description / PDF	Quantity
GF440300 Altech Corporation	EGFP 40A480Y277V AC 300MA 3P+N 5	0
GFL2C10300S Altech Corporation	MCCB+EGFP 10A120240V AC 300MA C	0
1D20UR Altech Corporation	1D20UR 20A MCB D CHAR 1 P 277VAC	0
2BU25R Altech Corporation	2BU25R 25A MCBBCHAR2P 480Y/277VA	12
1B13UM Altech Corporation	1B13UM13A CIRCUIT BREAKER B CHAR	0
1CU25R Altech Corporation	1CU25R 25A MCB C CHAR 1P277VACUL	0
S-TS400NU-FTU-LL-300 Altech Corporation	CIRCUIT BREAKER 300A480V AC 3P 3	0
GFL2C15100SN Altech Corporation	MCCB+EGFP 15A120240V AC 100MA C	0
1B4UM Altech Corporation	1B4UM 4A CIRCUIT BREAKER B CHAR	0
US-4 Altech Corporation	SURGE UNIT VARISTOR + RC 24 48VD	1
MMS-63H-13A Altech Corporation	MANUAL MOTOR START 65KA 9-13A	0
3CU4L Altech Corporation	3CU4L4.0AMCBCCHAR3P 480Y/277VACU	0
GFL2B16030SN Altech Corporation	MCCB+EGFP 16A120240V AC 30MA B T	0
3G12UM Altech Corporation	3G12UM 12ACIRCUIT BREAKER G CHAR	0
2G08UM Altech Corporation	2G08UM 0.8A CIRCUIT BREAKER G CH	0
GFR4D30100 Altech Corporation	EGFP+OL 30A480Y277V AC 100MA D T	0
GFR2C15030 Altech Corporation	EGFP+OL 15A277V AC 30MA C TRIP 1	2
3B63UM Altech Corporation	CIRCUIT BREAKER63UM 63A B CHAR 3	0
DC1CU20L Altech Corporation	DC1CU20L20A MCB C CHAR 1P125VDCU	72
DC2DU16L Altech Corporation	DC2DU16L16A MCBDCHAR 2P250VDCUL4	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