Technical Parameters Parameter Specification Product Name ABB SACE Emax PR121/P Protection / Trip Unit Type Electronic Protection Release / Trip Unit Compatible Series ABB SACE Emax Low-Voltage Air Circuit Breakers Installation Mounted on circuit breaker (3-pole or 4-pole) Protection Functions Overload (L), Short-circuit (S), Instantaneous (I), Earth fault (G) — depending on version/configuration User Interface DIP switches, LEDs for alarms/trips Self-Supply Yes — unit is self-powered by breaker current for protection function External Power (Optional) Auxiliary supply for extended functions and external devices Communication Interfaces Optional connection to external displays or PCs via communication modules Adjustable Settings Current thresholds, trip delays, neutral settings (when applicable) Standards Compliance IEC 60947-2 (Low-voltage circuit breakers standard) Operating Frequency 50/60 Hz Weight Approximately 0.3–0.5 kg (varies by exact version) Indicators Multi-function LEDs for protection status and alarms Testing & Diagnostics Built-in test function; support for external test tools Configuration Tools (Optional) External programming / communication modules