African rural lighting electrical Ready Board Box SPD wiring and wire diameter specification wiring method: Parallel SPD (surge protector) should be selected and installed in parallel between the protected line and PE (protective grounding), close to the power inlet. Single phase connections are L N, L PE, N PE, and three-phase four wire connections are L1 L2 L3 N and N PE. Parallel connection can ensure that the SPD is in a high impedance state during normal operation, without affecting power supply; When encountering a surge, internal components quickly conduct, providing a low impedance discharge channel for surge current and protecting terminal equipment. Series connection will change the circuit structure, increase the risk of faults, and does not comply with IEC and domestic low-voltage distribution standards. It is not recommended to use it. Wire diameter requirement: not less than 6 square millimeters. According to GB 50952-2013 "Technical Specification for Lightning Protection Engineering of Rural Residential Buildings" and IEC 60364-4-44 standards, combined with common grounding scenarios in rural TT/TN in Africa, the conductor cross-section of SPD connecting phase and neutral wires should not be less than 6mm ² (copper core), and the conductor cross-section of PE grounding should not be less than 6mm ², and green/yellow dual color wires should be used. If using Class I (Type 1) SPD (suitable for direct lightning protection), the wire diameter needs to be increased to 16mm ². At the same time, the grounding wire should be short and straight, with a length not exceeding 0.5m, to reduce the influence of inductance and ensure discharge efficiency. Power off before installation of landing points, confirm that the SPD model matches the system voltage, fix it on the DIN rail, and reserve heat dissipation space. Prioritize copper core cables and strictly purchase according to wire diameter specifications to avoid heating or melting due to insufficient wire diameter. After wiring, check the terminal torque to ensure a secure connection. After powering on, observe the SPD status indicator light to confirm normal operation.