Hager CFA240J Residual Current Circuit Breaker 2P 40A 0.3A Type A

The Hager CFA240J is a high-quality 2-pole residual current circuit breaker (RCCB) engineered to provide essential electrical safety in modern distribution systems. This device is designed to detect leakage currents and automatically disconnect the circuit, effectively preventing electrical shocks and reducing the risk of fire hazards caused by insulation faults. With a robust construction and reliable performance, it serves as a critical component for maintaining safety standards in both residential and commercial electrical installations.

Advantages

The primary advantage of this Hager RCCB is its Type A classification, which ensures comprehensive protection against both alternating sinusoidal residual currents and pulsating direct residual currents. This makes it a versatile solution for modern environments where electronic devices and power supplies may introduce complex leakage current profiles. The device is built for durability and consistent operation, ensuring that electrical circuits remain protected under various load conditions while maintaining high sensitivity to potential faults.

Suitable for

• Residential electrical distribution boards
• Commercial building power systems
• Protection of circuits with electronic equipment
• General electrical safety and fire prevention

When it may not be suitable

This device is not intended for use in circuits requiring overcurrent protection, as it is a residual current circuit breaker and does not feature integrated thermal or magnetic trip mechanisms for short-circuit or overload protection. It should be paired with a separate miniature circuit breaker (MCB) to ensure full system protection.

Key specifications

• Number of poles: 2
• Rated current: 40A
• Residual current sensitivity: 0.3A
• Type: A

How to use

The Hager CFA240J must be installed by a qualified electrician within a standard distribution board or consumer unit. It is mounted onto a DIN rail, ensuring secure mechanical attachment. The input and output conductors should be connected according to the terminal markings and local electrical wiring regulations. Once installed, the device should be tested using the integrated test button to verify its mechanical and electrical functionality.

What to consider before purchase

• Verify that the rated current of 40A is sufficient for the specific circuit load.
• Ensure the 0.3A sensitivity is appropriate for the intended application, as this is typically used for fire protection rather than direct human contact protection.
• Confirm compatibility with existing DIN rail mounting systems.

Usage recommendations

Regularly test the residual current circuit breaker using the built-in test button at least every six months to ensure the mechanism remains operational and the device continues to provide reliable protection.