Questions regarding UPS power supply specifications

This post was last edited by hanhaigang128 on 2023-7-17 at 12:44. This is a mode of UPS (it provides 220VDC output, similar to 220VAC; for reference only). No dual-power switching device is required; the main power supply and the bypass power supply (it is recommended that these two power inputs come from different sources in the electrical system to ensure reliable power supply) feed directly into the UPS, whose output is then sent to the instrument cabinets or instrument power cabinets； Of course, there are also integrated compact UPS units that take in power via a 220VAC supply line; you can also add a dual-power switching device (with an automatic switching time of just a few dozen milliseconds). This dual-power switching device is powered by two separate mains supplies, and the 220VAC output from it is fed directly into the UPS.

According to general UPS power supply specifications, if only a single UPS is used, usually only one power supply circuit is required from the electrical system. If dual UPS units are used, electrical power supply for two circuits is usually required, that is, each UPS needs its own power circuit. This is because a dual UPS configuration provides redundancy and backup functionality; when one of the UPS units fails, the other can continue to supply power. So, under normal circumstances, a dual UPS requires two power supplies from the electrical system. However, the specific requirements may vary depending on the actual circumstances, and they need to be determined based on the specific requirements of the project and equipment. .

Three paths are okay, as shown in your diagram, but STS is built into the UPS itself! Of course, two power supplies work just fine as well; it’s written here that a bypass and the direct supply from the mains can use one supply line! You still lack an isolation transformer here; it’s best to add bypass and direct mains power supply as well, so that the quality of the power supply is guaranteed and the equipment won’t get damaged: lol

This post was last edited by feng*aosa on 2023-7-22 at 16:07. The UPS function diagram provided on page 2 is very illustrative. The only difference is that this diagram shows the functions of a certain type of UPS; the actual functions of a UPS may vary, with some having only the functions indicated by the red circle. But it can be understood simply as the difference between discrete and integrated designs; the functionality of the entire system remains roughly the same. The main power supply and bypass power supply referred to in the specifications are the input and bypass shown in the diagram. For electrical systems, it usually involves installing two switch devices at one location, with wires running from each of them to you. If precision is required, it can be drawn from different phase wires (in which case phase synchronization of the UPS may be necessary, meaning that the output phase and the bypass must be synchronized). Additionally, the standard that should be referenced is HG/T 20509-2014, not 20592. .

Both use two mains power supplies; in the case of a single UPS, one mains supply enters the cabinet, while another enters the UPS before reaching the cabinet； With dual UPS, there are two power inputs to the UPS, which then feed into the cabinet. As for different busbars, as mentioned above, it’s best to segment them separately. Standardization isn’t always that absolute; experts sometimes just… consider the policies and the level of strictness in a given region. Originally, it was three-phase power that went to the UPS cabinet; APC power supplies imported from abroad. The power supply also comes from the distribution EPS, with various protections in place.