The Schneider Electric A9Z21280 is an Acti9 iID residual current circuit breaker (RCCB) — a 2-pole, 80 A device with 30 mA earth-leakage sensitivity, Type A protection, and a 10 kA rated conditional short-circuit current.
80 A rated current (In) at 220–240 V AC 50/60 Hz covers the main incoming feed for a sub-distribution board or a heavy load like a large commercial kitchen or HVAC unit. Type A detection means it catches both sinusoidal AC residual currents and pulsating DC residuals (typical from rectifiers, VFDs, or switching power supplies), so it's suited for mixed-load panels where electronics share the circuit. Voltage-independent tripping means the RCCB operates without needing a power supply from the line — it will still trip on a lost neutral or a dropped phase. In practice, coordinate it with a 10 kA MCB or fuse ahead of it. The 6 kV rated impulse withstand voltage (Uimp) means it handles surge events common in industrial environments without nuisance tripping.
Clip-on DIN rail mount, 36 mm wide (4 modules). The toggle control has a contact position indicator and accepts a padlocking device for lockout/tagout.