# BR-20 3P Type 2 20kA Surge Protective Device for TN-C Systems
## Introduction to Surge Protection in TN-C Systems
The BR-20 3P Type 2 20kA Surge Protective Device (SPD) is specifically designed to protect electrical installations in TN-C systems from transient overvoltages. TN-C systems, where the neutral and protective earth functions are combined in a single conductor (PEN), present unique challenges for surge protection that this device effectively addresses.
## Key Features of the BR-20 SPD
High-Performance Protection
The BR-20 offers a nominal discharge current (In) of 20kA per phase, providing robust protection against lightning-induced surges and switching transients. Its Type 2 classification means it’s designed for installation at distribution boards as secondary protection.
TN-C System Compatibility
This SPD is specifically engineered for TN-C earthing systems, featuring appropriate connection configurations that account for the combined PEN conductor. It ensures safe operation while maintaining the integrity of the TN-C system.
Advanced Thermal Protection
Equipped with thermal disconnectors, the BR-20 automatically disconnects from the circuit in case of overheating or end-of-life conditions, preventing potential fire hazards.
## Technical Specifications
| Parameter | Value |
|---|---|
| Nominal Discharge Current (In) | 20kA (8/20μs) |
| Maximum Discharge Current (Imax) | 40kA (8/20μs) |
| Voltage Protection Level (Up) | ≤ 1.5kV |
| Response Time | < 25ns |
| Operating Temperature Range | -40°C to +80°C |
## Installation Considerations
Proper Mounting
The BR-20 should be installed as close as possible to the equipment being protected, preferably at the main distribution board. The connecting conductors should be kept as short as possible to minimize inductance.
System Coordination
For comprehensive protection, the BR-20 should be used in coordination with Type 1 SPDs at the service entrance and Type 3 SPDs near sensitive equipment, following the cascade protection principle.
Maintenance Requirements
While the BR-20 requires minimal maintenance, regular visual inspections are recommended to check the status indicator and ensure the device hasn’t reached its end-of-life condition.
## Benefits of Choosing BR-20 for TN-C Systems
- Enhanced equipment protection against lightning and switching surges
- Reduced downtime and maintenance costs
- Compliance with IEC 61643-11 standards
- Compact design for easy installation in existing panels
- Reliable performance in harsh electrical environments
## Conclusion
The BR-20 3P Type 2 20kA Surge Protective Device offers an optimal solution for protecting TN-C systems against transient overvoltages. Its robust design, high discharge capacity, and TN-C-specific features make it an excellent choice for industrial, commercial, and residential applications where TN-C ear
