# BR-20 1+1 Type 2 20kA Surge Protective Device for TT and TNS Systems
## Introduction to Surge Protection
In today’s world of sensitive electronic equipment, surge protection has become an essential component of any electrical installation. The BR-20 1+1 Type 2 20kA Surge Protective Device (SPD) offers reliable protection against transient overvoltages for both TT and TNS earthing systems.
## Key Features of the BR-20 SPD
The BR-20 1+1 Type 2 SPD boasts several important features that make it an excellent choice for electrical protection:
– 20kA discharge capacity per mode (Iimp)
– 1+1 protection mode configuration
– Suitable for both TT and TNS earthing systems
– Compact and modular design
– Visual status indication
– Thermal disconnection for safety
## Understanding the 1+1 Protection Mode
The “1+1” designation refers to the SPD’s configuration that provides protection between:
– Live conductors (L-N)
– Live conductors and earth (L-PE, N-PE)
This dual protection approach ensures comprehensive coverage against various types of surges that might enter the electrical system.
## Technical Specifications
Parameter | Value
Type | Type 2 (Class II)
Nominal Discharge Current (In) | 20kA
Maximum Discharge Current (Imax) | 40kA
Voltage Protection Level (Up) | ≤ 1.5kV
Response Time | < 25ns
Operating Temperature Range | -40°C to +80°C
## Installation Considerations
When installing the BR-20 SPD, consider these important factors:
– Should be installed after the main circuit breaker
– Requires proper earthing connection
– Follow manufacturer’s guidelines for cable lengths
– Regular maintenance checks recommended
– Replace when status indicator shows end-of-life
## Benefits for TT and TNS Systems
The BR-20 is specifically designed to work effectively with both TT and TNS earthing arrangements:
### For TT Systems
– Provides effective protection against earth faults
– Handles the higher voltage stresses typical in TT systems
– Maintains system stability during surge events
### For TNS Systems
– Offers balanced protection for all conductors
– Handles the neutral-earth relationship in TNS configurations
– Protects against both common-mode and differential-mode surges
## Conclusion
The BR-20 1+1 Type 2 20kA Surge Protective Device represents an excellent solution for protecting electrical installations in both TT and TNS systems. Its robust design, high discharge capacity, and flexible configuration make it suitable for a wide range of applications, from residential to commercial installations. By implementing proper surge protection like the BR-20, you can significantly reduce the risk of equipment damage and downtime caused by electrical surges.
