Analyze fuse and circuit breaker coordination, selectivity, and discrimination based on IEC 60947-2 and IEC 60269 standards for proper electrical protection.
Analyze fuse and circuit breaker coordination, selectivity, and discrimination based on IEC 60947-2 and IEC 60269 standards.
Ensure proper coordination between upstream and downstream protection devices to prevent unnecessary tripping and maintain system reliability.
Verify time discrimination between protection devices to ensure only the faulted section is isolated while maintaining supply to healthy sections.
Analyze time-current characteristics of protection devices to ensure proper coordination and optimal protection performance.
Verify that protection devices can safely interrupt fault currents and provide adequate protection for electrical equipment.
Based on IEC 60947-2 (circuit breakers) and IEC 60269 (fuses) standards for international compliance and best practices.
Calculate let-through energy (I²t) to ensure cable protection and verify that downstream devices can handle fault energy.
The Fuse/Circuit Breaker Coordination Tool is a professional electrical engineering tool designed to analyze protection device coordination in electrical systems. Based on IEC 60947-2 and IEC 60269 standards, this tool helps electrical engineers ensure proper selectivity, discrimination, and safety in electrical protection schemes. Whether you're designing new systems or analyzing existing installations, this tool provides the analysis you need for reliable electrical protection.
Input upstream protection device specifications including type, rating, breaking capacity, and characteristic curve.
Example: MCB 32A, Type C, 6kA
Input downstream protection device specifications. Ensure proper rating ratio for selectivity (typically 1.6:1 or higher).
Example: MCB 16A, Type C, 6kA
Enter fault current, cable impedance, system voltage, and power factor for accurate coordination analysis.
Example: 5kA fault, 0.1Ω cable
Review coordination status, selectivity analysis, operating times, and recommendations for optimal protection.
Status: Good coordination
Selectivity Requirements:
Safety Considerations:
Protection coordination ensures that only the protection device closest to a fault operates, isolating the faulted section while maintaining supply to healthy parts of the electrical system.
Selectivity is the ability of protection devices to discriminate between fault locations. Good selectivity means only the downstream device trips for faults in its protected zone.
Time discrimination is the time difference between upstream and downstream device operation. Minimum 200ms is typically required for reliable coordination.
MCB characteristic curves (B, C, D) define the tripping characteristics: Type B (3-5× In), Type C (5-10× In), Type D (10-20× In). Choose based on load characteristics.
Let-through energy (I²t) is the energy that passes through a protection device during fault clearing. It must be less than the thermal withstand of protected cables.
Ensure proper rating ratios (1.6:1 minimum), sufficient time discrimination (200ms minimum), and verify breaking capacity exceeds fault current. Consider using time-delayed upstream devices if needed.
If coordination fails, consider increasing upstream device rating, using time-delayed upstream protection, or changing device types. The tool provides specific recommendations.
Yes, you can mix fuses with circuit breakers or use different circuit breaker types. The tool analyzes coordination between any combination of protection devices.
Motor circuits require special consideration for starting currents. Use motor protection devices or consider starting current in coordination analysis.
Calculations are based on IEC standards and provide good accuracy for typical applications. For critical systems, consult manufacturer data and consider additional factors.
Cascading allows upstream devices to provide backup protection when downstream devices fail. The tool checks if upstream devices can safely interrupt fault current.
For high fault currents, ensure all devices have adequate breaking capacity. Consider using current-limiting devices or series-rated combinations for cost-effective solutions.