Uninterruptible power supply installation implementation standards

Uninterruptible power supplies or UPSs are battery chargers consisting of a combination of convertors, switches and energy storage devices (such as batteries), constituting a power system for maintaining continuity of load power in case of input power failure. 10 CFR 430 Appendix Y 2.27.

An UPS can be considered a source of standby power or emergency power depending on the nature of the critical loads. The amount of power that the UPS must supply also depends on these specific needs. These needs can include: a combination of the preceding needs.

An UPS system is an alternate or backup source of power with the electric utility company being the primary source. The UPS provides protection of load against line frequency variations, elimination of power line noise and voltage transients, voltage regulation, and uninterruptible power for critical loads during failures of normal utility source.

The UPS is also required to comply with the EN50171 standard in the specific case of protecting safety equipment, in addition to complying with the 62040 series standards. This standard specifies the general requirements for independent centralized power supply systems for safety equipment.

It is therefore sufficient to keep the UPS connected to the power supply, even if not in use, so that the batteries remain alive and active . The UPS must always be connected to the batteries and report any disconnections or malfunctions promptly so that it is able to function correctly .

• VI (Voltage Independent): this is the UPS in which the variations in the power supply voltage are stabilised by electronic/passive regulation devices within the limits of routine operation .