Selecting a UPS.

Classifications help in UPS selection

When choosing UPS equipment how can you ensure that it will perform as expected and the information provided by different vendors is comparable? 

The classification categorises the different UPS topologies:

1.      Stand-by

Stand-by UPS supplies power to the load directly from utility until a utility power failure occurs. The UPS then turns on the inverter and supplies load from the battery. These UPSs are also called Off-line.

2.      Line-Interactive

Line interactive UPS compensates for deficiencies in utility voltage by running the UPS inverter parallel to utility voltage when needed. The UPS output is therefore partly dependent of the quality of the utility power. Several marketing names are used for these UPSs, Single Conversion, Parallel On-line and Delta Conversion to name a few.

3.      Double Conversion

Double conversion UPS regenerates the electricity constantly. The output power is completely independent of the input power.  These units are most often called On-Line UPS’s. These UPS’s are able to correct all 9-power problems (Power failure, Sag, Surge, Under voltage, Line noise, Over voltage, Frequency variation, Switching transient and Harmonic distortion). These UPS’s are used with all mission critical electrical equipment, which cannot afford to go down (servers, communication equipment etc.). Critical equipment both inside and outside the office environment should always be protected by Series-9 UPS. These UPS’s also feature possibility for extending the battery back up time up to several hours.