Miniature Circuit Breaker Schneider Electric A9F03320 — 20 A, 133 V, 10 kA, IP20, 54×78.5×91 mm

Schneider Electric A9F03320 is a single-pole miniature circuit breaker designed for overcurrent protection in panel and distribution board installations. Rated for 20 A nominal current and suitable for systems up to 133 V, this device combines compact dimensions with a high breaking capacity of 10 kA, and provides IP20 degree of protection. Its enclosure and mounting dimensions of 54×78.5×91 mm make it compatible with many standard electrical panels used in residential and light commercial applications.

Advantages

The breaker delivers consistent overload and short-circuit protection with a 10,000 A interrupting capacity, helping to limit damage to wiring and equipment. Its compact form factor saves space inside distribution boards while allowing straightforward DIN-rail mounting and wiring. IP20 protection ensures basic protection against accidental contact with live parts in enclosed installations. The specified electrical ratings and clear physical dimensions simplify selection and installation planning.

Suitable for

• Overcurrent protection in residential distribution boards
• Light commercial electrical circuits and sub-distribution panels
• Protection of branch circuits feeding lighting and small loads
• Retrofit replacements where a compact, single-pole breaker is required

Key specifications

• Nominal current: 20 A
• Rated voltage: up to 133 V
• Breaking capacity: 10,000 A (10 kA)
• Degree of protection: IP20
• Mounting: DIN-rail compatible, panel mounting
• Dimensions (W×D×H): 54 × 78.5 × 91 mm
• Poles: single-pole configuration

How to use

Install the miniature circuit breaker on a compatible DIN rail inside the distribution board or panel, observing local electrical codes and safety practices. Connect the incoming supply conductor to the line terminal and the outgoing load conductor to the load terminal, ensuring secure torque on terminal screws. Verify the system voltage does not exceed 133 V and that the protected circuit current does not exceed 20 A. After installation, switch the breaker on and test operation by applying the intended load and, if required, performing a trip test under controlled conditions.

Recommendations

Use this breaker as part of a properly designed electrical distribution system; coordinate with upstream protection and follow national wiring regulations. For environments with dust, moisture, or higher ingress requirements, consider devices with higher IP ratings or enclosed cabinets. Periodically inspect terminals for tightness and signs of heating, and replace the breaker after any significant fault event.