Daily maintenance and repair methods and standards for UPS uninterruptible power supply

UPS, as an uninterruptible power supply containing energy storage devices, is mainly used to provide uninterrupted power to some equipment that requires high power stability. This article summarizes the methods and precautions for daily maintenance and repair of UPS, helping instrument personnel strengthen the management and maintenance of UPS equipment.

A、 Daily maintenance:

1. Inspect once a day.

2. Check the UPS display control panel to ensure that all display units on the LCD display panel are in normal operation, all power supply operating parameters are within the normal range, and there are no faults or alarm messages in the displayed records. Check if all signal lights are working properly.

3. Record the operation status, voltage, and current values of UPS every day, and promptly address any issues found.

4. Listen for any suspicious changes in the noise during operation. If it is a power frequency machine, pay special attention to the sound of the input and output isolation transformers of the UPS. When there is an abnormal "squeaking sound", there may be poor contact or insulation between the turns of the winding. When there is low-frequency "cymbal sound", it may be due to magnetic bias in the transformer.

5. Observe whether the filter screen of the fan is clogged.

6. Keep the exterior of the battery clean.

7. Check the operating status of the battery pack: When the operating temperature rises, the battery does not heat up during float charging. If individual batteries are found to be heating up, the cause should be immediately checked and dealt with in a timely manner. If the entire battery pack is found to be heating up, the operating status of the battery should be checked first (there is a certain temperature rise during strong charging or discharging), whether the float charging current is too high or the battery pack has external micro short circuits, etc. If problems are found, they should be dealt with in a timely manner.

8. Check the connection points of the battery pack for tightness, oxidation, and apply Vaseline oil.

9. Appearance inspection: whether there is mechanical damage and whether there are small animal carcasses inside the equipment; Is there any conductive dirt or dust inside the device; Does the accumulated dust affect heat dissipation.

10. Measure the voltage of the battery pack and individual cells once a month. The voltage of each battery should be between 13.5-14V. If the voltage of the battery is found to be low or uneven, it should be dealt with in a timely manner.

11. Simulated mains power failure test: Consciously discharge the battery to the DC bus, and immediately restore the AC power supply after normal operation. The battery should be able to automatically cut off the discharge circuit. The operation time of this test should not exceed 5 minutes, and the UPS output should be ensured to be uninterrupted. The simulated power failure test should be conducted every three months.

12. Check the capacity of the battery once a year for two purposes: to understand the actual operating capacity of the battery; Activate the battery pack once to make the battery capacity uniform.

13. Every year, the mains power supply is verified by disconnecting the main power supply and backup power supply separately from the incoming cabinet to check the integrity of the incoming switch.

14. Regular inspections are conducted on all UPS switching modules every year, using the method of disconnecting the mains and bypass power from the power supply input side. While verifying the accuracy of the switching function of the switching module, the inverter function is also checked for normal operation. (When operating, it is necessary to follow the steps. In the case where both the mains and bypass are disconnected, the output power supply should always have voltage as normal.).

15. The UPS control system should be regularly inspected for the following: check whether the display module of the control displays consistent with the operating conditions, and whether there are no black screens or garbled characters on the display. If this phenomenon occurs, replace the display module as soon as possible; Check if there are any abnormal sounds on the display control screen, and promptly handle any alarms or other abnormal phenomena; Check the operation buttons on the display control screen, confirm that each button is functioning properly, switch and check the relevant functions and parameters, and promptly report and handle any abnormalities.

16. UPS uninterruptible power supply should avoid frequent startup and shutdown, and it is best to stay in the startup state for a long time. If it is necessary to shut down, it should be turned on at least 5 seconds after shutdown.

17. Check whether the battery pack to UPS wires are aging. If they are aging, replace them with wires of the same current carrying area in a timely manner, and try to avoid increasing unnecessary wire lengths.

18. Check if the mains power supply is always in normal operation. If the mains power supply is always in normal operation, the UPS uninterruptible power supply will not have the opportunity to work, and its battery may be damaged due to long-term float charging. Therefore, the UPS uninterruptible power supply that has not been used for a long time should be manually forced to work regularly, which can activate the battery and also verify whether the UPS uninterruptible power supply is in normal condition.

19. Check if communication is normal and data is accurate, and promptly handle any abnormal situations.

20. Ensure that the load capacity connected does not exceed two-thirds of the UPS power capacity.

21. The operation of energy storage batteries is entirely in float charging state, and they should be charged and discharged regularly, with a recommended interval of about 3 months, and discharged at least once a year. Before discharging, the battery pack should be evenly charged to achieve the balance of the entire battery pack.

22. It should be thoroughly cleaned once every quarter. Secondly, during dust removal, check for any looseness or loose contact between the connecting and plug-in components.

23. When the UPS battery system malfunctions, identify the cause and distinguish between the load and the UPS power system; Whether it is the host or the battery pack, gradually investigate and solve it.

B、 Maintenance methods and standards:

1. Under normal use, UPS power supply requires minimal maintenance work on the host, and should generally be thoroughly cleaned once every quarter. Secondly, during dust removal, check for any looseness or loose contact between the connecting and plug-in components.

2. The energy storage battery pack adopts maintenance free batteries, but this only eliminates the previous work of measuring ratios, proportioning, and adding distilled water at regular intervals. The maintenance and repair work of other parts is still very important. The extensive maintenance and repair work of the UPS power system mainly focuses on the battery part, and the battery maintenance work mainly includes the following types:

The operation of energy storage batteries is entirely in float charging state, in which case they should be discharged at least once a year. Before discharging, the battery pack should be evenly charged to achieve the balance of the entire battery pack. Be clear about the outdated batteries that existed in the battery pack before discharge. If one reaches the discharge termination voltage during the discharge process, the discharge should be stopped and the lagging battery should be eliminated before continuing the discharge.

Verification discharge is not about first pursuing the percentage of discharge capacity, but about paying attention to discovering and handling outdated batteries, and conducting verification discharge experiments after processing them. This can prevent accidents and prevent backward batteries from deteriorating into reverse polarity batteries during discharge.

Normally, each group of batteries should have at least 8 labeled batteries as a reference for understanding the working condition of the entire battery pack. The labeled batteries should be measured regularly and recorded.

The items that need to be checked regularly in daily maintenance include: cleaning and detecting the voltage and temperature at both ends of the battery; Check for looseness and corrosion at the connection point, and assess the pressure drop of the connecting strip; Whether the appearance of the battery is intact, whether there is shell deformation and leakage; Is there any acid mist escaping around the pole and safety valve; Is the host device functioning properly.

3. When the UPS battery system malfunctions, the cause should be identified first to distinguish between the load and the UPS power system; Is it the host or the battery pack. Although the UPS host has a fault self checking function, it is located on the opposite side rather than on the same point, making it convenient to replace parts. However, to repair the fault point, a lot of analysis and testing work still needs to be done. In addition, if there is a malfunction in the self checking part, the displayed fault content may be incorrect. Please handle this situation based on the on-site fault as appropriate.

4. When batteries with voltage reversal, large voltage drop, large pressure difference, and acid mist leakage are found in the battery pack, corresponding methods should be promptly adopted for restoration and repair.

5. The appearance and wiring inspection should meet the following requirements:

The hardware configuration, labeling, and wiring of the device should comply with the requirements of the drawings.

The appearance quality and soldering quality of the components on each plugin of the device should be good, all chips should be plugged tightly, the model should be correct, and the chip placement position should be correct.

The distance between conductive parts such as electronic components, printed circuits, and solder joints and metal frames should be greater than 3mm.

The components of the device are securely fixed without any looseness, and the appearance of the device should be upright without obvious damage or deformation.

Each plug should be flexible in insertion and extraction, with good positioning between each plug and socket, and appropriate insertion depth.

The terminal block connection of the device should be reliable, and the labeling should be clear and correct.

Switches, modules, buttons, keyboards, etc. should be operated flexibly and have a good tactile feel.

All components should be clean and in good condition.

6. Battery replacement should meet the following requirements:

For the DC power supply of the dual battery, battery replacement can only be carried out after completing the DC load transfer.

The DC power supply for a single battery can only be replaced after connecting a substitute battery.

When replacing the battery, ensure that the DC power supply is turned off and the battery is disconnected.

Insulation tools should be used when working on battery systems.

Special attention should be paid to preventing short circuits when making inter electrode connections.

7. Cleaning treatment: The contamination of cabinets and plugins should be cleaned to prevent adverse phenomena such as crawling and short circuits. Please note that the back panel sockets and terminals inside the cabinet can be blown with a hair dryer and should not be touched by any object. Pay attention to blowing from the back to the front and from the top to the bottom when the plug is unplugged to prevent dust from falling into the socket and causing poor contact; The blowing of dust on other parts of the cabinet should be done first, and the blowing of dust on the chassis should be done last.