ABB – ELR72V24 (2CSG452120R1202) – Front‑Panel Electronic Residual‑Current Relay

The ELR72V24 is an electronic residual-current (earth-leakage) monitoring relay from ABB, designed to ensure safety in low-voltage distribution systems. Front-panel mountable and compliant with IEC/EN 60947‑2 Annex M, it operates with an external toroidal sensor to detect leakage currents between 0.03–30 A, triggering a shunt-trip on associated breakers. Configurable via DIP switches and featuring both automatic/manual reset modes. Powered by 24–48 V AC/DC.

 Key Specifications

• Part / Model No: ELR72V24, ABB 2CSG452120R1202  

• Auxiliary Supply: 24–48 V AC/DC ±20 %  

• Leakage Sensitivity (IΔn): 0.03–30 A (adjustable via DIP settings K‑0.1/1/10)  

• Response Time (Δt): 0–5 s (via DIP switches, with time scaling switch) ()

• Output: 1 changeover contact, 5 A @ 250 V AC  

• Configurable Modes: Fail‑Safe ON/OFF, Auto/Manual Reset via DIP  

• Protection Rating:

  • Front: IP52 with cover, IP40 without

  • Terminal area: IP20  

• Standards: IEC/EN 60947‑2 Annex M certified  

• Consumed Power: ~4 VA  

• Dimensions: 72 × 72 mm panel cutout (depth 68–80 mm)  

• Operating Temperature: −10 °C to +60 °C; humidity ≤ 95 %