Earth leakage protection has become mandatory in most residential and commercial installations. But not all RCCBs are equal. The ABB F202 A-25/0.03 is a Type A device, which means it detects not only sinusoidal AC fault currents (the kind from resistive and inductive loads) but also pulsating DC fault currents — the kind produced by modern electronics, switch-mode power supplies, and appliances with rectifiers.

Why Type A Instead of AC
An AC-only RCCB may fail to trip on a fault current that contains a DC component. For example, a faulty washing machine with a rectified supply, a variable speed drive, or a battery charger can generate pulsating DC leakage. Type A devices respond reliably to such currents up to 6 mA of smooth DC. Given the proliferation of electronic equipment in homes and offices, Type A is now considered the minimum standard in many countries.

Rated Values and Practical Use
The F202 A-25/0.03 is a 2-pole unit, suitable for single-phase circuits (phase + neutral) up to 230V. The 25A continuous rating matches typical final circuits for socket outlets, lighting, and small appliances. The 30mA sensitivity provides additional protection against direct contact (faults through a person). Surge current withstand is 250A (8/20µs waveform), meaning the device does not trip on transient leakage spikes from lightning or switching surges.

Short-Circuit Coordination
The RCCB alone does not provide short-circuit protection. It must be combined with an upstream MCB or fuse. The F202 series is rated for a short-circuit withstand capacity of 10kA when protected by a gG 100A fuse or a suitably rated circuit breaker. In practice, install a 16A or 20A MCB upstream (or a combined RCBO) for full protection.

Installation Details
Mounts on 35mm DIN rail per EN 60715. Height 85mm, width 35mm (2 modules), depth 69mm. Terminals accept conductors up to 25mm², with a tightening torque of 2.8 Nm. Operating temperature –25°C to +55°C. The device includes a test button (UT) that operates between 100V and 240V AC. Mechanical life is 20,000 cycles, electrical life 10,000 cycles.

Compatibility and Accessories
The F202 A-25/0.03 is part of ABB's F200 series, which shares accessory compatibility with S200 MCBs. Auxiliary contacts and shunt trips can be mounted on the right side. The device is EAN 8012542782506. RoHS compliance is confirmed.

When to Choose 2-Pole vs 4-Pole
For a single-phase supply, 2-pole (one phase, one neutral) is correct. The neutral is switched, which is required for TN-S and TN-C-S systems where the neutral is considered a live conductor. For three-phase systems, use the 4-pole version (F204). Do not use a 4-pole device on a single-phase circuit — it will work but wastes space and cost.