An uninterruptible power supply (UPS) is mainly used to ensure computers continue to function when the main source of power goes out. A UPS allows users to shut down computer properly to ensure critical information is protected. These devices are also essential for computer servers, especially those used for businesses.
But, there may be instances when the UPS may fail due to a number of reasons, including the battery exceeding its shelf life or the need to update the firmware. In these instances, it is advisable to have an N+1 UPS configuration or a parallel redundancy configuration. In this configuration, there is always another UPS module used as a backup in case the main UPS module fails to function. The N stands for a UPS module while +1 stands for an additional or spare UPS module. Due to this, an N+1 UPS configuration has at least two UPS modules connected to a device. For computer servers requiring six UPS modules, an N+1 UPS configuration means the system will have a total of seven UPS devices for use. The UPS devices are integrated into a single UPS system.
The load is shared equally by all UPS modules connected to the computer server during normal operations. When one of the modules fails after the main source of power goes out, the remaining modules can provide suitable power to the system. This configuration also ensures the protection of computer servers while one of the UPS devices is under maintenance.
While an N+1 UPS configuration may increase equipment costs due to the additional UPS module used, it also enhances reliability and avoids unnecessary downtime for computer servers.