AC Load Bank Maintenance Guidelines

1. Daily Maintenance: Must be Done Before and After Each Use/Daily​
 

1000kW load bank

 

Daily maintenance is the foundation for preventing failures. It should be performed before starting the test and after shutting down each time. The focus is on the equipment's appearance, connection status, and basic functions. The operation is simple but crucial.​

Appearance and Cleaning Inspection: Wipe the equipment shell with a dry soft cloth to remove surface dust, oil stains, and debris, preventing poor heat dissipation due to dust accumulation. Check if the shell is deformed, cracked, or has peeling paint. If damage is found, repair it in time to prevent internal components from getting damp or being invaded by foreign objects. Check if the display screen, indicator lights are in good condition, and if the buttons are sensitive. If the screen is garbled, the indicator lights are not on, or the buttons are stuck, stop using the equipment and troubleshoot.​

Connection Component Inspection: Check the input and output cables one by one to see if the outer layer of the cables is worn, aged, or cracked, and if the connectors are loose, oxidized, or rusted. If connector oxidation is found, gently polish it with fine sandpaper to remove the oxide layer, then apply conductive paste to enhance conductivity. Ensure that the connection between the cable plug and the equipment interface is firm to avoid current fluctuations or equipment errors during testing due to poor contact.​

Basic Function Pre-Testing: Before starting the machine, confirm that the equipment's power supply voltage matches the grid voltage to avoid damaging the internal circuit due to overvoltage or undervoltage. After starting the machine, perform a "no-load self-test" to observe whether the equipment can normally enter the operating system and whether there are error codes (such as overload, over-temperature, and other fault prompts) during the self-test. If the self-test passes, connect a low-power load for a short-term test to verify whether the load adjustment function and data collection function (such as voltage, current, and power display) are normal.​

2. Regular Maintenance: Systematic Inspection Monthly/Quarterly​

Regular maintenance should be carried out at a fixed cycle (it is recommended to conduct a basic inspection once a month and an in-depth maintenance once a quarter). It focuses on the internal core components, heat dissipation system, and electrical safety of the equipment, and requires the use of basic tools (such as a multimeter and screwdriver) for operation.​

Core Component Testing: Open the equipment side cover (in the power-off state), and check whether internal components such as power resistors, contactors, and relays have signs of burning, peculiar smells, or looseness. Use a multimeter to measure the resistance value of the power resistor and compare it with the standard resistance range in the equipment manual. If the resistance deviation exceeds ±5%, replace the resistor in time. Check whether the contactor contacts are ablated or dented. If the contacts are severely worn, replace the contactor to avoid load out of control due to poor contact.​

Heat Dissipation System Maintenance: Clean the heat dissipation fan filter. If the filter is severely blocked, it can be removed and rinsed with clean water (install it after drying) to ensure smooth air intake of the fan. After starting the equipment, listen to the operation sound of the heat dissipation fan. If there is abnormal noise (such as jamming, friction sound) or the fan does not rotate, check whether the fan motor is faulty and replace the fan in time to prevent the equipment from overheating protection. Check whether there is dust accumulation in the heat dissipation air duct, and use compressed air (low pressure) to blow off the dust to ensure that heat is discharged smoothly.​

Electrical Safety Inspection: Use a multimeter to measure the insulation resistance between the equipment shell and the live wire. The insulation resistance should be ≥1MΩ (≥0.5MΩ in humid environments). If the insulation resistance is too low, check whether the internal wires are damaged or damp, and use the equipment after repair. Check whether the equipment grounding terminal is firm and the grounding wire is in good condition to ensure that the grounding resistance is ≤4Ω, avoiding safety accidents in case of electric leakage. Check whether the internal terminal blocks are loose, and fasten them one by one with a screwdriver to prevent local overheating or circuit failure caused by loose wiring.