Key points for inspecting the lines of residential solar energy systems

Preparations before the examination

Cut off the power supply: Before starting the line inspection, the power supply of the residential solar system must be cut off first, including the power supply of all related equipment such as solar panels, inverters, and batteries (if any). This is to ensure the safety of the inspectors and prevent electric shock accidents. For instance, when turning off the power, make sure that the power indicator light of the inverter goes out and the solar panels no longer output current.

Prepare the necessary inspection tools: Get ready, such as a multimeter, screwdriver, wire stripper, insulating tape, etc. Multimeters are used to measure parameters such as voltage, current and resistance of circuits, screwdrivers and wire strippers are used to disassemble and connect circuits, and insulating tape is used to repair damaged insulation layers.

Visual inspection

Line integrity: Carefully inspect all the lines of the solar energy system to see if there is any damage, breakage, wear or aging. Damage to the lines may lead to safety hazards such as leakage and short circuits, affecting the normal operation of the system. For instance, check whether there are cracks or scratches on the outer skin of the circuit and whether the internal wires are exposed.

Connection point inspection: Check the connection points of the circuit, such as plugs, sockets, terminal blocks, etc., to see if they are loose, have poor contact or are rusty. Problems at the connection points may lead to poor current transmission, affecting the power generation efficiency and stability of the system. You can gently shake the connection points by hand to see if there is any loosening. At the same time, observe whether there are any signs of oxidation or rust at the connection points.

Insulation condition: Check whether the insulation layer of the circuit is intact, and whether there is any damage, peeling or aging. The function of the insulating layer is to prevent current leakage and ensure the safety of personnel and equipment. If any damage to the insulation layer is found, it should be repaired in time with insulating tape.

Electrical performance inspection

Voltage measurement: Use a multimeter to measure the output voltage of the solar panel under different lighting conditions to ensure it meets the design requirements. Generally speaking, the output voltage of solar panels under standard light conditions (1000W/m²) should be within the specified range. If the voltage is too low, it may be caused by reasons such as damaged solar panels, excessive resistance of the connection lines or insufficient light.

Current measurement: Measure the output current of the solar energy system and check if the current is stable. Unstable current may lead to equipment damage or reduced power generation efficiency. The stability of the current can be determined by observing the changes in the reading of the multimeter. If the current fluctuates greatly, the cause needs to be further investigated.

Resistance measurement: Measure the resistance of the circuit and check for any short circuits or open circuits. Under normal circumstances, the resistance of the circuit should be within a certain range. If the resistance is zero, there may be a short circuit. If the resistance is infinite, there may be an open circuit. The ohm range of a multimeter can be used for measurement.

Grounding inspection

Grounding wire connection: Check whether the grounding wire of the solar energy system is firmly connected and whether the grounding resistance meets the requirements. The function of the grounding wire is to guide the leakage current of the system into the ground, ensuring the safety of personnel and equipment. You can use a screwdriver to check whether the connection bolts of the grounding wire are tightened. At the same time, use a grounding resistance tester to measure the grounding resistance. Generally, it is required that the grounding resistance does not exceed 4Ω.

Grounding electrode inspection: Check whether the grounding electrode is intact, and whether there is any corrosion, damage or loosening. The grounding electrode is an important component of the grounding system. If there is a problem with the grounding electrode, it will affect the grounding effect. You can check whether the material of the grounding electrode is rusty and whether the contact between the grounding electrode and the soil is good.

Line marking and route inspection

Clarity of identification: Check whether the identification on the line is clear and accurate, including the name, number, voltage level and other information of the line. Clear line markings help inspectors quickly identify the lines, facilitating maintenance and management. If the identification is ambiguous or missing, it should be supplemented and improved in a timely manner.

Rationality of routing: Check whether the routing of the line is reasonable, and whether there is any crossing, entanglement or interference with other equipment. Unreasonable line routing may lead to problems such as line wear and signal interference. It is possible to check whether the line is laid along the predetermined path and whether it maintains a safe distance from other pipes and cables.

Post-inspection handling

Problem recording and rectification: Make detailed records of the problems found during the inspection process, including their location, nature, severity, etc., and promptly formulate rectification measures. For some simple problems, such as loose circuits and damaged insulation layers, they can be repaired on the spot. For some complex issues, such as equipment malfunctions and aging lines, it is necessary to arrange for professional personnel to carry out maintenance or replacement.

Power restoration and testing: After the problem rectification is completed, restore the power supply of the solar energy system and conduct a comprehensive test to ensure the normal operation of the system. The test contents include power generation efficiency, voltage stability, current transmission, etc., to ensure that the system meets the design requirements.