LOAD BANK TESTING
Load bank testing places a resistive load onto the output of the UPS whose technical performance can then be tested and verified. Mains failures can be simulated and the UPS put into standby, on-line and Eco mode and the maintenance bypasses switched (both internal and external).
Load bank testing can also be used to verify the battery runtime capacity and recharge times. Batteries are connected into battery strings, which may be paralleled together to give a UPS system its overall battery capacity. Using a load bank to test the battery provides several benefits. Firstly the critical connected loads do not have to be used to test the battery, where a sudden failure could lead to a load crash. Secondly, the battery test on a load bank can be run for far longer and long enough to identify any failure in battery capacity. If any of the battery strings has a failing or weak battery it can take some time on discharge before the overall DC battery voltage across the strings starts to collapse. The only other way to test the battery is to inspect and test each battery block using a hand-held battery tester and then to analyse the recorded results.