Residual Current Circuit Breaker Schneider Electric A9D20620 2‑pole 20A 30mA Type AC (leakage relay)

Schneider Electric A9D20620 is a 2‑pole residual current circuit breaker with a 20 A rated current and 30 mA residual current sensitivity, designed as type AC. It combines earth‑leakage detection with overcurrent interruption in a compact unit intended for use in residential and light‑commercial distribution boards. The device detects alternating residual currents and trips to reduce risk of electric shock and to limit fire hazard from leakage currents.

Advantages

The leakage relay provides coordinated protection by combining residual current detection with circuit interruption at 20 A nominal current and 30 mA sensitivity. Its two‑pole design isolates both conductors in single‑phase circuits, and the AC type is optimized for detection of sinusoidal alternating residual currents. The compact form factor fits standard DIN‑rail distribution boards and is manufactured to recognized safety standards for predictable operation and mechanical compatibility.

Suitable for

• Residential electrical distribution boards and consumer units
• Light commercial installations where AC residual current protection is required
• Protection of circuits supplying sockets, lighting, and small appliances
• Replacement or upgrade of existing two‑pole residual current devices in compatible panels

When it may not be suitable

This device is type AC and detects only sinusoidal alternating residual currents; it may not reliably detect pulsating DC or composite leakage currents generated by some modern electronic equipment or frequency‑driven loads. For environments with electronic inverters, photovoltaic systems, EV chargers, or variable frequency drives, a device with broader detection characteristics (e.g., type A or type B) should be considered.

Key specifications

• Poles: 2‑pole design (neutral and phase switching)
• Rated current: 20 A
• Residual current sensitivity: 30 mA
• Residual current type: AC (sinusoidal alternating only)
• Function: combined residual current detection and overcurrent interruption
• Mounting: DIN‑rail compatible modular device for distribution boards

How to use

Install the unit in a compatible DIN‑rail distribution board according to local electrical regulations and wiring diagrams. Connect phase and neutral conductors to the designated terminals, ensuring correct polarity and secure tightening of terminals. Test the residual current function after installation using the built‑in test button or an external RCD tester to confirm trip at the specified sensitivity. Follow manufacturer torque values and commissioning procedures, and label the protected circuit for future maintenance.

What to consider before purchase

• Verify that type AC residual current detection is appropriate for the loads on the circuit
• Confirm the nominal current rating of 20 A matches the circuit wiring and connected load
• Ensure physical compatibility with your distribution board (DIN‑rail space and terminal arrangement)
• Check local regulations for required residual current sensitivity for specific circuits (e.g., bathrooms, kitchens, outdoors)

Usage recommendations

Use this 2‑pole 20 A, 30 mA AC residual current circuit breaker in standard single‑phase circuits where detection of sinusoidal alternating leakage currents is required. For circuits with electronic or DC components, select a device with appropriate detection type. Regularly test the device after installation and during periodic inspections to ensure continued protection.