Surge arrester B+C 4P (T1+T2 AC) BY7-40/4-275 87.785

Protection of electrical installations against overvoltage

The BY7-40/4-275 surge arrester is a reliable device designed to protect electrical installations in residential and industrial buildings. It provides effective protection against the effects of lightning strikes and switching surges, minimizing the risk of equipment damage and system failures. It is a key element ensuring safety and continuity of power supply.

This arrester, class B+C (Type 1+2), performs perfectly in TN-S networks. Its design allows for a quick response to sudden voltage changes, dissipating excess energy to ground and protecting connected devices. Mounting is done on a standard TH35 rail, and the compact dimensions (4 modules, i.e. 72 mm wide) allow for easy adaptation to the existing distribution board.

Characteristics and application

The device is characterized by high strength parameters: impulse current 5kA (10/350µs), maximum discharge current 40kA (Imax), rated discharge current 20kA (In) and rated voltage 275VAC (Uc). The protection level of 1.2kV (Up) guarantees effective protection of sensitive electronic devices. Thanks to this, BY7-40/4-275 arresters are used in protecting:

• electrical installations in residential buildings,
• electrical installations in public buildings,
• industrial installations,
• alarm and fire protection systems,
• RTV and household appliances,
• computers and servers.

Key features and benefits

• Versatility: The B+C class arrester provides protection against both direct lightning strikes (class B) and surges from the power grid or switching loads (class C).
• High efficiency: Parameters such as Iimp 5kA, Imax 40kA and In 20kA guarantee effective protection even with large surges.
• Easy installation: Mounting on a TH35 rail is simple and quick, which translates into time savings during installation.
• Compact dimensions: It occupies only 4 modules in the distribution board, which facilitates integration with the existing infrastructure.
• Optical indication of operation: Allows for quick identification of the situation in which the arrester has operated and requires checking the condition of the installation.
• Compliance with standards: The product has a CE declaration confirming compliance with applicable safety standards.