Circuit Breakers

Part Number	Description / PDF	Quantity
R58-1A NTE Electronics, Inc.	CIR BRKR THRM 1A 250VAC 50VDC	0
R59-8A NTE Electronics, Inc.	CIR BRKR THRM 8A 250VAC 32VDC	516
R185-35A NTE Electronics, Inc.	CIRCUIT BREAKER,THERMAL 35A	74
R185-80A NTE Electronics, Inc.	CIRCUIT BREAKER,THERMAL 80A	80
R59-3A NTE Electronics, Inc.	CIR BRKR THRM 3A 250VAC 32VDC	766
R59-10A NTE Electronics, Inc.	CIR BRKR THRM 10A 250VAC 32VDC	358
R58-8A NTE Electronics, Inc.	CIR BRKR THRM 8A 250VAC 50VDC	281
R185-100A NTE Electronics, Inc.	CIRCUIT BREAKER,THERMAL 100A	43
R58-20A NTE Electronics, Inc.	CIR BRKR THRM 20A 250VAC 50VDC	855
R185-60A NTE Electronics, Inc.	CIRCUIT BREAKER,THERMAL 60A	44
R59-5A NTE Electronics, Inc.	CIR BRKR THRM 5A 250VAC 32VDC	333
R59-20A NTE Electronics, Inc.	CIR BRKR THRM 20A 250VAC 32VDC	10
R58-30A NTE Electronics, Inc.	CIR BRKR THRM 30A 250VAC 50VDC	344
R58-25A NTE Electronics, Inc.	CIR BRKR THRM 25A 250VAC 50VDC	419
R58-3A NTE Electronics, Inc.	CIR BRKR THRM 3A 250VAC 50VDC	338
R59-12A NTE Electronics, Inc.	CIR BRKR THRM 12A 250VAC 32VDC	49
R185-70A NTE Electronics, Inc.	CIRCUIT BREAKER,THERMAL 70A	39
R185-30A NTE Electronics, Inc.	CIRCUIT BREAKER,THERMAL 30A	70
R58-15A NTE Electronics, Inc.	CIR BRKR THRM 15A 250VAC 50VDC	751
R59-4A NTE Electronics, Inc.	CIR BRKR THRM 4A 250VAC 32VDC	326

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