Technical Specifications / Parameters Parameter Specification Manufacturer Type Code OVR T2-T3 3N 20-275 P QS Brand / Series ABB OVR Series (Surge Protection Devices) Device Type Type 2 Surge Protective Device (SPD) Application Main distribution board or sub-distribution board protection (according to IEC 62305). Rated Voltage (Uc) 275 V AC (for 230/400V AC systems). This is the maximum continuous operating voltage. Network Configuration 3N (Three-phase + Neutral protection). It protects all phases (L1, L2, L3) relative to Neutral (N). Nominal Discharge Current (In) 20 kA (8/20 µs) per phase. This is the standard test current for Type 2 SPDs. Maximum Discharge Current (Imax) Significantly higher than In (e.g., 40 kA or 65 kA 8/20 µs). Voltage Protection Level (Up) Low (e.g., ≤ 1.5 kV). This is the residual voltage that appears across the terminals when discharging In, indicating its clamping performance. Protection Mode L-N, N-PE (Depending on design, it may protect between each Line and Neutral, and Neutral to Earth). Short-Circuit Withstand Rating High (e.g., 25 kA RMS according to IEC 61643-11). Thermal Protection Integrated thermal disconnector for safe failure mode. Status Indicator Green/Red window indicating operational health (Green = OK, Red = fault/end of life). Remote Signaling Contact (QS) Yes. The QS suffix indicates a built-in Changeover (SPDT) auxiliary contact for remote alarm signaling (e.g., to a BMS or PLC). Mounting DIN Rail Mounting (35mm). Standards & Approvals IEC/EN 61643-11, UL 1449 (4th Ed.) Type 2, CE.