The wiring design of a household energy storage system is a core link that determines the system’s efficiency, stability, and safety. It involves the connection of multiple components, including energy storage batteries, solar panels (if equipped), inverters, distribution boxes, and household loads, and must follow the principles of rational layout, safe insulation, reduced energy loss, and convenient maintenance. Scientific wiring design not only ensures the efficient transmission of electrical energy but also minimizes potential risks such as short circuits, electric leakage, and electromagnetic interference, laying a solid foundation for the long-term stable operation of the entire system.

First, the selection of wires and cables must meet the system’s operating requirements and safety standards. Different parts of the system require different types of cables: for the DC side (between solar panels and inverters, and between batteries and inverters), DC-specific cables with high insulation performance, high temperature resistance, and UV resistance should be selected, such as PV1-F or H1Z2Z2-K photovoltaic special cables, which can withstand a temperature range of -40°C to 120°C and a voltage level higher than the system’s maximum DC voltage (usually 600V or 1kV). For the AC side (between inverters and distribution boxes, and between distribution boxes and household loads), flame-retardant cables such as ZC-BV or WDZ-YJY should be used, with a voltage level of 300/500V in line with household electrical standards. The cross-sectional area of the cables should be calculated based on the maximum current of the system: for battery charging and discharging circuits, it should be selected according to 1.25 times the maximum charging/discharging current; for photovoltaic DC circuits, it should be selected according to 1.56 times the short-circuit current of the components, to avoid overheating and energy loss caused by insufficient cross-sectional area. Copper-core cables are preferred for their good conductivity and corrosion resistance, while aluminum-core cables are not recommended due to their high resistance and poor stability.

The layout of the wiring system must be rational and standardized. DC cables and AC cables should be laid separately, avoiding the same pipe or trough to prevent electromagnetic interference that could affect the system’s performance and measurement accuracy; if they must cross, they should be arranged vertically at 90 degrees to minimize interference. The wiring should be neat and orderly, avoiding excessive bending, pulling, or pressing to prevent damage to the cable insulation layer; the length of the cables should be minimized to reduce energy loss, and if long-distance wiring is required, the cross-sectional area of the cables should be appropriately increased to compensate for voltage drop. The connection points between cables and components (batteries, inverters, distribution boxes) must be tight and reliable, wrapped with insulation tape or heat-shrinkable tubes to ensure good insulation and prevent loose connections or electric leakage; battery interconnections should use flexible cables (such as RVV cables with a temperature resistance of 105°C or higher) to reduce wear caused by vibration, and protective sleeves should be added to avoid cable damage.

Grounding and protection measures are essential in wiring design. The entire energy storage system, including batteries, inverters, distribution boxes, and cable metal casings, must be reliably grounded in accordance with NEC 250 and manufacturer’s instructions to prevent electric shock accidents caused by equipment leakage or insulation damage. A dedicated grounding wire should be set up, with a cross-sectional area not less than 1/3 of the main cable cross-sectional area, and the grounding resistance should meet relevant standards (generally not exceeding 4 ohms). In addition, overcurrent protection devices (such as fuses and circuit breakers) should be installed in key parts of the circuit, such as the battery output end, inverter input/output end, and distribution box, to quickly cut off the circuit when a short circuit or overcurrent occurs, protecting the system components and wiring from damage. For outdoor wiring, weatherproof and UV-resistant cables should be used, and the connection points should be sealed to prevent moisture and dust from entering, which could cause insulation degradation; underground wiring should use armored cables to avoid damage from external forces.

Wiring design should also consider maintainability and scalability. The wiring should be labeled clearly, indicating the function, direction, and voltage level of each cable, to facilitate later inspection, maintenance, and troubleshooting. The distribution box should be installed in an accessible location, with sufficient space for operation and maintenance; the wiring should be arranged in a way that allows for easy replacement of components or expansion of the system (such as adding more batteries or solar panels) in the future. All wiring operations must comply with national and local electrical codes, such as the NEC 2023, OESC 2024, and IEC 60364, and be inspected and accepted by professional personnel before the system is put into use to ensure the safety and reliability of the wiring system.