Residual current device P 304 4P 40 A 300 mA Type A DX3 series 411780

The residual current device P 304 4P 40 A 300 mA Type A, series DX3, is a critical component ensuring safety in electrical installations. Designed to protect users from electric shock and equipment from the effects of earth faults and overloads, this device is suitable for both residential and industrial applications requiring high reliability and effective protection.

Functions and Applications

The P 304 residual current device from the DX³ series protects against indirect contact—situations where dangerous voltage may appear on the casing of electrical equipment. Thanks to its Type A sensitivity, it effectively detects leakage currents caused by insulation damage in wiring. With a rated current of 40 A and a rated differential current of 300 mA, this device is ideal for protecting circuits with higher power demand. The rated differential current of 0.3 A ensures rapid response in case of hazard.

Construction and Installation

The device is designed for DIN rail mounting, simplifying installation and replacement. It occupies 4 module widths, enabling efficient use of space in the distribution board. Its robust construction from high-quality materials guarantees long-term, fault-free operation. The trip mechanism lock prevents accidental re-energizing after tripping—enhancing safety during maintenance or fault diagnosis. The cross-section of the connected single-core cable can range from 0.75 mm² to 50 mm², and multi-core cable from 0.75 mm² to 35 mm², ensuring compatibility with various conductor types used in electrical installations.

Specifications and Compliance with Standards

The P 304 device complies with stringent safety standards, featuring a rated insulation voltage (Ui) of 500 V and an impulse withstand voltage (Uimp) of 4 kV. Its short-circuit withstand capacity (Icw) reaches up to 10 kA, demonstrating high resilience against sudden current surges. The device operates at a frequency of 50 Hz and a rated voltage of 400 V (AC). The IP20 protection rating safeguards against finger contact and solid objects larger than 12.5 mm in diameter. Operating ambient temperature ranges from -25°C to +60°C, enabling use in diverse environmental conditions.