Whenever a power outage happens, an uninterruptible power supply (UPS) can be quite handy. They allow businesses to shut down their main computer servers during a power outage to save any important information. Since there may be instances when the UPS may not function properly, a backup system or an N+1 configuration is normally used to deal with these situations. The parallel redundant configuration is one of these N+1 configurations that these businesses may use.
The parallel redundant configuration is made up of at least two UPS devices connected to the equipment. Power goes through the UPS devices before it reaches the equipment. Power going into the equipment goes through at least two different UPS devices. When the main power source goes out, the battery on the UPS provides power to the equipment.
If one of the UPS devices does not work properly, the backup UPS will provide the necessary power to the equipment. The backup UPS in this configuration is always ready in providing power to important equipment since its battery is always charged. This setup can be expanded easily as the power needs of the equipment increases. Setting up the system is also easy and cost-effective.
While this setup has a number of advantages over an isolated redundant configuration, it also has some disadvantages. One of these disadvantages is the need to use the same model and brand of UPS. The UPS devices are also connected at a single point to the power source and equipment. In this situation, if this single point fails, the whole system will fail.
It is important to select the most suitable redundant UPS configuration to ensure all important equipment are protected at all times in case of power outages.
References:
http://www.apc.com/salestools/SADE-5TPL8X/SADE-5TPL8X_R3_EN.pdf
http://www.schneider-bgclub.com/catalog/1_Aparatura_NN/4.UPS/Katalozi/Design%20guide%20UPS.pdf