Parallel Redundant UPS

Often called N+1 Redundancy, this technology uses a series of UPS operating in parallel. Typically, there will be one more module in the configuration than is necessary to support the load, enabling a faulty module (battery or UPS) to be hot-swapped out without interrupting the supply to the load.

Originally only available on very large UPS this technique has recently become available at the lower power ratings and the price differential is now very acceptable. The individual modules are almost always of On-line design.

This approach is essential for mission-critical applications, or in demanding environments such as industrial process control where down-time for any reason is a costly and unwelcome interruption.

In an IT environment this design is complementary to the RAID array and hot-standby fileservers and like those technologies is directed to removing single point-of-failure weaknesses.