1、 Daily basic maintenance (daily/weekly)
1. Running status monitoring
Core parameter check: Real time monitoring of the following parameters through UPS panel display or management software:
Input voltage (confirmed to be within its wide range nominal value, such as 100-280VAC), input frequency (50/60Hz);
Output voltage (stable at 220VAC ± 2% or within the precision range required by the equipment), output frequency;
Load rate (recommended to be controlled at 30% -70% for a long time, avoiding long-term full load or light load<10%);
Battery voltage, charging current, battery capacity (if supported), ensure that the battery is in a floating charge state (not discharged or overcharged).
Abnormal warning attention: Pay attention to whether the UPS issues an alarm (sound and light alarm), such as input voltage exceeding the limit, battery undervoltage, overload, fan failure, etc., and promptly investigate the cause.
2. Environmental management
Temperature and humidity control:
Maintain the ambient temperature at 15-25 ℃ (preferably 20 ℃) and avoid exceeding 30 ℃ (high temperature can accelerate the aging of capacitors and batteries, especially for high-frequency modules that are sensitive to heat dissipation);
The relative humidity should be controlled between 40% -60%. High humidity can easily cause circuit corrosion, while low humidity can easily generate static electricity.
Dust prevention and ventilation:
Check daily for debris accumulation around the UPS, ensuring that the air inlet/outlet (usually located in front, back, or on both sides of the body) is unobstructed and the ventilation gap is ≥ 50cm;
Clean the surface dust of the machine body with a dry brush or compressed air every week to prevent dust from entering and accumulating inside (high-frequency circuits are sensitive to dust, which can easily cause short circuits or poor heat dissipation).
2、 Regular in-depth maintenance (monthly/quarterly)
1. Maintenance of core components
Battery system (critical maintenance item):
Monthly inspection of the appearance of the battery pack: check for leaks, bulges, deformation of the shell, and oxidation of the wiring terminals (if green copper rust appears, wipe it with a dry cloth dipped in baking soda);
Every quarter, use a multimeter to measure the voltage of a single battery (under float charging, 12V batteries should be between 13.5-13.8V, and 2V batteries should be between 2.23-2.27V), internal resistance (tested by professional equipment, the internal resistance of newly added batteries should be ≤ 20m Ω, and if the internal resistance doubles after aging, it needs to be replaced);
Conduct a "deep discharge test" every six months: disconnect the mains power, discharge the UPS at 50% load until the battery voltage drops to the protection point (such as 10.5V/cell), then restore the mains power for charging, and record the discharge time (if it drops by 20% from the initial value, the battery needs to be replaced).
Lead acid batteries (common types):
Lithium battery (if equipped): Avoid long-term full charge storage, set the charging limit (such as 80%) through the management software, and perform regular (every 3 months) charging and discharging cycles to activate.
Cooling system:
Monthly check the operation status of the fan: there is no abnormal noise or stoppage. If the fan fails, it needs to be replaced immediately (high-frequency module cooling relies on the fan, overheating will trigger protection shutdown);
Disassemble the panel every quarter (power off operation) and clean the dust on the internal heat sink and filter with compressed air (dust accumulation can cause a decrease in heat dissipation efficiency of more than 30%).
Input/output circuit:
Quarterly inspection of wiring terminals: Check if the screws of the input circuit breaker and output terminal block are loose (reinforce with a wrench to avoid poor contact and heat generation);
Use an infrared thermometer to detect the temperature of key nodes (such as rectifiers and inverter output terminals). The normal temperature should be ≤ 60 ℃, and if it exceeds 70 ℃, contact problems or module failures should be investigated.
2. Performance testing (every six months/year)
Wide input range verification:
Simulate input voltage fluctuations through a voltage regulator (from the nominal lowest value to the highest value, such as 100V → 280V), observe whether the UPS output is stable (voltage and frequency have no sudden changes), and whether the switching time is ≤ 2ms (high-frequency online should be uninterrupted);
Test the sudden rise/drop of input voltage (such as 220V suddenly dropping to 120V or rising to 260V), and confirm that the UPS is not down or has no output abnormalities.
Load switching and protection testing:
Perform a "mains battery" switching test: disconnect the mains power, confirm that the UPS seamlessly switches to battery power, automatically switch back after restoring the mains power, and cut off power without load;
Overload protection test: Gradually increase the load to 120% of the rated power, verify whether the UPS issues an alarm and switches to a bypass within the set time (usually 10-60 seconds) to avoid module damage.
Bypass system inspection:
Manually switch to bypass mode, check if the bypass output voltage and frequency are normal, and confirm that the bypass is synchronized with the mains power (to avoid generating surge current during switching);
Test the "Inverter Fault → Automatic Bypass" function: Simulate an inverter fault (such as disconnecting the inverter power supply), confirm that the UPS can switch to the bypass within 5ms, and ensure that the load is not powered off.
3、 Long term life maintenance (annual/every 3 years)
1. Firmware and software updates
Regularly log in to the UPS management platform (such as SNMP cards, specialized software), check for firmware updates (the manufacturer will fix compatibility or stability issues), and follow the instructions to upgrade (backup configuration before upgrading to avoid power outages).
2. Core module detection
Please have professional engineers inspect the rectifier and inverter modules every 3 years
Measure the stability of the rectifier output DC voltage (such as 380VDC ± 5%);
Detect the waveform of the inverter (observe the output as a sine wave with a total harmonic distortion THD<3% using an oscilloscope);
Check capacitors, inductors, and other components: If there are bulges, leaks, or oxidized pins, replace them in a timely manner (high-frequency module capacitors have a lifespan of about 5-8 years and are vulnerable parts).
3. Maintain records and contingency plans
Establish a maintenance ledger to record the maintenance time and testing data (such as battery voltage, load rate, and fault conditions) for each maintenance, in order to trace the aging trend of equipment;
Develop emergency plan: clarify the load switching process in case of UPS failure (such as manual bypass and activation of backup UPS), and conduct regular drills (1-2 times a year).
