UPS power supply is an indispensable power supply protection device for data centers, and its role is becoming more and more important. But for a long time, because some users did not understand the working principle and technical characteristics of UPS, and did not pay attention to the management and maintenance of UPS, its service life was shortened, and the failure rate increased. As a result, it affected the performance of UPS and caused the UPS system. Fault. UPS power equipment failures can be divided into service failures and component failures.

     In the product failure, the selection of UPS power equipment is the first level. If this level is not well selected, the hidden danger will be buried first. The connection and use of UPS power equipment is the second level. With good equipment, if there is no good connection scheme, hidden dangers will be buried. A certain TV station was misled by the manufacturer due to the connection scheme. The power supply UPS failures of more than a dozen programs continue to occur, and most of them are unpredictable. This has been the case for several years, which has made maintenance personnel nervous and brain-wrenching. The connection plan is a systematic project, and it cannot be controlled by maintenance personnel. I had no choice but to ask factory engineers to come on duty at major events and festivals. The manufacturer's engineers can only give users psychological comfort at this point.

　　 The so-called service failure refers to the failure caused by the misoperation of the operation and maintenance personnel, the wrong judgment of the failure phenomenon, the improper measures taken and the empirical diagnosis, etc. UPS service failures can be roughly divided into knowledge failures, operational failures, delayed failures, maintenance failures, empirical failures, environmental failures, and sudden power failures.

1. Knowledge failure

(1) The basic concept is unclear and easy to be misled by manufacturers. For example, a highway bidding for UPS requires the UPS to have the ability to continue supplying power without discharging the battery after one or two phases are interrupted in the input. Because some manufacturers advertise that the battery of his UPS does not discharge after one phase of the input is interrupted, the UPS still has 50% of the power supply capacity; after the input of two phases is interrupted, the battery still does not discharge, and the UPS has 25% of the power supply capacity, which extends the battery's power. Service life. Users think that this performance is good, and careful analysis is not difficult to find its drawbacks: if you want to enjoy its advantages, you must purchase a UPS power supply that is 4 times the load capacity, otherwise the current load will not be driven after one phase is broken. Then again, what should I do if the UPS breaks the two wires behind the input switch? Repair it or not? When? Will it be repaired after the power is completely cut off? How to solve this series of problems. If the user really buys such a UPS power supply according to the actual capacity of the load, this is a huge hidden danger, which is a problem that cannot be solved by operation and maintenance.

(2) Reasons for inconvenience. For example, some users have been using a foreign brand machine since the last century. At that time, due to objective reasons, despite the low input power factor, low efficiency, large size, high power consumption and high price, it was impossible and inconvenient to solve it. Nowadays, new models that are much superior to the original models have been published. For example, the new high-frequency online UPS saves 50,000 kilowatts of electricity per 100 kilowatts per year compared with the original industrial frequency online UPS. The computer room can save millions of kilowatt-hours of electricity every year. However, for some reason, the energy-consuming machine was still included in the bid book without choosing the energy-saving equipment. I was afraid that it would not be safe to do so, and the structural characteristics of the machine were written into the bid book. This not only increases the investment and floor space of air-conditioning equipment, but also undoubtedly lays down hidden dangers for future operations. This is another problem that cannot be solved in operation and maintenance.

(3) Pursue low prices. Some users think that UPS power supplies are all the same, so they pursue low prices, which leads to failures. For example, a highway headquarters was greedy for cheap, and it installed the machine on the first day and caught fire on the second day; a life insurance company purchased a machine at a low price and burned almost all the input circuits of IT equipment in less than half a year due to a UPS failure, causing the system to be paralyzed. ; Another example is a megawatt data center with multiple UPSs connected in parallel, and within a few months of installation, one of the inverter power tubes in one of the UPSs has broken down and all UPSs have tripped...

2. Operational failure

　Because of the importance of the load carried by the UPS, in order to ensure the safe and reliable operation of the UPS, various products have their own set of safe operation procedures, which are written into the manual for users to refer to and implement. However, there are individual maintenance personnel who disagree with this, and do not follow the established procedures, but operate at will according to their own understanding. As a result, problems sometimes occur; there are also unconscious operating failures, for example, during repairs or maintenance, due to disassembly of a certain unit. One device accidentally damaged the adjacent device without finding it, and a secondary fault occurred when the power was turned on; the meter lead mistakenly short-circuited certain two points when checking the fault; when connecting the external battery, the positive and negative poles were mistakenly mistaken; there is a single Or several battery connection strips are not tightened or the battery switch is not closed, the battery cannot be discharged when the mains power fails and the UPS stops; the power supply bureau makes the original phase sequence wrong when the mains line is modified or repaired, which will also cause the UPS Unable to start or conversion failure; UPS forgets to start the inverter after power-on, which will also cause shutdown when the mains power is cut off; because the staff on duty throws food in the computer room randomly, rats are attracted, and the rats bite the cables or enter the machine. Causes short-circuit faults between cables or components; unshielded remote signal cables and AC lines are wired in parallel, causing faults due to coupling interference, etc.

3. Maintenance failure

　　 Although there are few periodic maintenance contents of UPS, these contents are very necessary, and there must be a set of strict procedures for these maintenance. Failure to maintain equipment regularly as required is an important cause of failure.

　　 For example, some UPS power supplies have not been maintained or maintained for a long time. Once the equipment is found to be unstable, it has to be repaired. After opening the case, a thick layer of dust has accumulated on the circuit board and components. As long as the dust is removed with a hair dryer and a vacuum cleaner, the equipment can be restored to normal. For another example, after a UPS is repaired, the maintenance personnel add the mains power to the input terminal and forget to start the inverter or close the battery switch. When the next mains power failure occurs, the UPS shuts down because the inverter cannot be started.

　　 Even if it is the experience gained from the experience of dealing with the fault several times, it can not be used rigidly. For example, a user who has operating experience in brand A UPS operates a newly installed brand B UPS without reading the manual, but directly starts the DC start based on experience. Because all the UPSs he is familiar with can be started by DC, this machine does not have a DC start function, and of course it can't start. So, he opened the case with a screwdriver and stabbed the relay when he saw the relay. Although the inverter started, it smoked immediately and the power tube was damaged. He didn't know that a UPS with a DC start function has a certain procedure when it starts: when the DC start switch is turned on, the control circuit works first, and then the inverter is driven, that is, it starts normally. But this UPS has no DC start function. While the control circuit is working, the inverter is also starting. The unstable state during the transition causes the two power tubes of the inverter to be turned on at the same time and burn out.

Some maintenance personnel think that they have mastered the principles of UPS during the training, and only need to learn some troubleshooting methods. However, short-term training can only learn some simple fault judgment methods, specific faults should be analyzed in detail, and experience can only be used as a reference.

It can be seen from the above points that a set of scientific and effective methods should be formulated and strictly followed for UPS maintenance, so that it is possible to avoid the above-mentioned man-made failures, so as to greatly reduce the failure rate of UPS, and truly achieve uninterrupted performance. Electrical equipment provides safe and reliable clean power.