UPS power failure is the main culprit behind most UPS disasters. Although UPS power supply is easy to be damaged prematurely, users do not have to be victims. The following will introduce the five major causes of UPS premature failure, and how to prevent this failure.
When the backup UPS power supply is normally supplied by the city power supply, the city power supply directly supplies power to the load through the AC bypass channel and then through the transfer switch, and the inverter in the machine is in the stop working state. This kind of UPS is essentially equivalent to a commercial power regulator with very poor voltage stabilizing performance. In addition to the improvement of the amplitude fluctuation of the mains voltage, it has no improvement on the frequency instability, waveform distortion and interference from the grid. Only when the mains power supply is interrupted or lower than 170V, the battery can supply power to the inverter of ups and provide AC power supply with stable voltage and frequency to the load. The advantages of backup ups are high operation efficiency, low noise and relatively low price. It is mainly suitable for the occasions with little fluctuation and low demand for power supply quality. What is UPS power supply? Online UPS power supply changes AC power supply into DC power supply when the power supply is normal.
Causes of premature failure of UPS power supply and maintenance methods:
No measures can be taken to prevent the UPS power supply from reaching its service life. However, avoiding the following errors can help ensure service life.
1. Poor storage of unused UPS power supply – even if the UPS power supply is not used, its life will start to decrease. That’s because the lead-acid ups will automatically release a small amount of energy.
In order to extend the storage life of UPS power supply, it is recommended that you charge it every three to four months. If you don’t, you may see a permanent capacity loss in just six months. You can also extend the life of an unused ups by keeping it at 50 ° f (10 ° C) or lower.
2. Higher ambient temperature – the rated capacity of each UPS power supply is based on an ambient temperature of 25 ° C (77 ° f). Any change (especially the temperature rise) will affect the performance and service life. Generally, for every 15 ° F increase in the recommended ambient temperature, the life expectancy of the UPS power supply will be reduced by 50%. Routine maintenance checks can help identify hot spots and verify ventilation conditions.
Whether the input voltage frequency range is wide, whether it has super lightning protection ability, whether the anti electromagnetic interference ability has passed the certification, etc. are the functional indexes that need to be considered when selecting ups. In the case of small power capacity or local power supply, which functional indicators should be valued to select UPS? In the case of small capacity or local power supply, small capacity UPS should be selected first, and then online or backup UPS should be selected according to the requirements of power supply quality. Backup UPS has 500VA, 1000VA, online UPS has 1kVA to 10KVA for users to choose. In the case of large power capacity or centralized power supply, which functional indicators should be valued to select UPS? In case of large capacity or centralized power supply, large capacity three-phase UPS should be selected. And consider whether there are ① output short-circuit protection; ② unbalanced load can be connected; ③ isolation transformer; ④ hot backup; ⑤ multi language graphic LCD display; ⑥ remote monitoring; ⑦ super monitoring software.
3. Excessive cycle – when UPS is operated by UPS during power failure, ups will be charged for future use, which is called discharge cycle. After installing the UPS power supply, the UPS power supply will reach 100% of its rated capacity. However, each discharge and subsequent charging will slightly reduce the capacity of UPS power supply.
4. Incorrect floating voltage – each UPS manufacturer will specify the charging voltage range for its own UPS design. If the UPS power supply continues to charge beyond these parameters, serious damage may be caused. Insufficient charging or low voltage will cause sulfate crystals to form on UPS power board. Over time, these crystals will harden and reduce the available capacity of the UPS power supply. Too high floating charge voltage will lead to too much hydrogen and oxygen, and may lead to internal drying. Once accelerated, internal drying will lead to thermal runaway, leading to failure and even fire.
5. Incorrect use of UPS power supply – upsups power supply is dedicated to UPS, just like other UPS power supply is dedicated to their respective electrical appliances. UPS power supply can provide high energy consumption in a short time (usually up to 15 minutes).
In a word, the deeper you step forward now, the easier you will be in operation and maintenance in the future.
Editor in charge ajx