The determination of UPS power supply capacity is based on the load capacity and nature. Choosing appropriate UPS can not only guarantee the quality of power supply, reduce failure rate, but also save investment and improve economic benefits. Generally speaking, the determination of UPS capacity is mainly to meet the needs of the current load, most of the UPS manufacturers in the product specifications given by the output power refers to the load power factor of 0.8.
UPS power capacity units
When we discuss the power of a UPS power supply, we will mention two parameters. For example, 3KVA / 2400W, or 10KVA900W. Both W and VA are capacity units of UPS power supply. W is effective power VA is apparent power. The nominal value of UPS power supply equipment is VA, the general technical parameters will be given the corresponding W value. W and VA have a conversion between the power factor. For example, 400W / 500VA can be calculated as a power factor of 0.8. The reason for this power factor is that in an AC system, part of the current (harmonic current) does not supply the load, resulting in apparent power VA, greater than the effective power W.
When selecting UPS power supply equipment, the calculated load power should not exceed the effective power. If more than the effective power, it will make the UPS power overload. Such a situation, UPS host will continue to alarm and bypass the power supply, so that UPS cannot play a continuous role.
At present, most of the UPS power supply systems sold in the market take VA (apparent power) as a unit, V means voltage, A means current, voltage multiplied by current means power, which is the capacity of UPS uninterruptible system. As illustrated by a 500VA uninterruptible power supply, when its output voltage is 110 V, It can supply current 4.55A, when your load demand current value more than 4.55 A, it means overload.
1. Understand the output power of UPS power supply battery inverter voltage
Here to 3K UPS as an example, this is a power 3 KVA battery inverter voltage 96V UPS power supply. These data are generally obtained from the company website or product information, different models of the battery pack voltage is not the same.
2. calculate the actual output power of UPS power supply
UPS power X0.7 = actual output power, 3KVAX0.7 equals 2.1KW (actual output), 2.1kW = 2100W.
3.Calculate the total capacity of battery pack
(Actual Output Power / Battery Voltage) X Delay Time = Total Capacity of Battery (AH) Delay time is clearly known by customers, such as 8 hours delay; (2100W / 96V) X8H = 175AH (total battery capacity)
4. Battery Selection
Here only to conventional battery reference, conventional 12V battery specifications are: 12V4AH, 12v7ah, 12V17AH, 12A24AH, 12V38AH, 12V65AH, 12V100 AH, there is a problem need to note that the capacity of the battery series after the capacity is equal to a battery, but the voltage increased. For example: 12V24AHX8 = 96V24ah (series battery pack capacity).
When buying UPS batteries, you need to know the actual capacity of the battery, which varies from brand to brand. Also need to know the real power of the actual load, thus deciding the capacity of the battery to choose large or small, to be flexible application.
Summary: The above is the UPS power capacity unit, UPS power capacity calculation method. When configuring UPS capacity in the first phase, we should give due consideration to the medium- and long-term development trends and selection of the models can be run side-by-side or multi-machine in the selection, so that when the medium- and long-term load capacity increases, through the UPS parallel expansion of its output capacity. Accordingly, when UPS input and output distribution panel is configured, several input switches and load shunt switches should be reserved for future expansion.
