# BR-20 4P Type 2 20kA Surge Protective Device for TNS Systems
## Introduction to Surge Protection in TNS Systems
The BR-20 4P Type 2 20kA Surge Protective Device (SPD) is specifically designed to protect TNS (Terre-Neutre-Séparé) electrical systems from transient overvoltages. These systems, commonly used in European installations, require specialized protection to maintain equipment safety and system reliability.
## 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 ensures it can handle the majority of surge events that reach the electrical distribution panel.
4-Pole Design for TNS Systems
With its 4-pole configuration (L1, L2, L3, N), this SPD is perfectly suited for TNS earthing arrangements where the neutral and protective earth are separate throughout the installation.
Advanced Thermal Protection
The device incorporates thermal disconnectors that automatically isolate the SPD from the circuit in case of overload, preventing potential fire hazards and ensuring system safety.
## Technical Specifications
- Nominal Discharge Current (In): 20kA (8/20μs)
- Maximum Discharge Current (Imax): 40kA (8/20μs)
- Voltage Protection Level (Up): ≤ 1.5kV
- Response Time: < 25ns
- Operating Voltage: 230/400V AC
- Frequency Range: 50/60Hz
- Operating Temperature: -40°C to +80°C
## Installation Considerations
Location in the Electrical System
The BR-20 should be installed at the main distribution board as the primary surge protection device. In larger installations, it may be complemented with Type 3 SPDs at sub-distribution points for complete protection.
Connection Requirements
Proper connection is crucial for effective operation. The SPD should be connected with short, straight conductors (preferably < 0.5m) to minimize inductive effects. Cross-sectional area of connecting conductors should be at least 6mm² for phase connections and 10mm² for earth connections.
Monitoring and Maintenance
The device features a visual status indicator showing operational state (green) and end-of-life status (red). Regular inspection is recommended, especially after significant surge events.
## Benefits of Using BR-20 in TNS Systems
The BR-20 4P Type 2 SPD provides comprehensive protection for TNS systems by:
- Preventing damage to sensitive electronic equipment
- Reducing downtime and maintenance costs
- Complying with IEC 61643-11 and EN 61643-11 standards
- Offering easy installation and maintenance
- Providing reliable performance in harsh electrical environments
## Conclusion
The BR-20 4P Type 2 20kA Surge Protective Device represents an optimal solution for protecting TNS electrical systems against transient overvoltages. Its robust design, high discharge capacity, and specific configuration for TNS arrangements make it an essential component for modern electrical installations where equipment protection and system reliability are paramount.
