UPS Back Up Time Collocation Skill
When mains fault, The UPS offers power to load depend on battery. A standard type UPS with battery(ies) inside. When mains fault, the UPS can continuous offer uninterruptible power for about several minutes or even several ten minutes. But the long backup type UPS collocates battery(ies) bank outside, is able to offer power for a long time, meet the user demand. Commonly, a long backup type UPS, with full load, can offer several hours.
And the battery is affected by the load, battery capacity, ambient temperature, battery discharge cut-off voltage, and so on. Commonly, after calculated the UPS backup time, you can calculate out the discharge current, and then understand the discharge time according to the battery discharge curve. What’s more, you can calculate the discharge power current by the following formula:
Discharge Current=UPS Capacity(VA)*Power Factor/UPS DC Voltage(VA)*Efficiency
This discharge current can be regard as this UPS, with full load, needed battery capacity for back up time is one hour.
For example, a UPS: power factor is 0.75, efficiency is 0.8, built in DC Current is 48V, so this UPS discharge one hour will need about: 48V-58.59Ah battery capacity, and if require back up for 2 hours, that is 59.59*2, can choice one bank batterie 48V100Ah or two banks 48V65Ah.
New：2013-03-13 Click：4071 <<< Return