BS EN 62040-3:2001

This standard applies to electronic indirect a.c. converter systems with electrical energy storage means in the d.c. link. The primary function of the uninterruptible power system (UPS) covered by this standard is to ensure continuity of an alternating power source. The uninterruptible power system may also serve to improve the quality of the power source by keeping it within specified characteristics. A variety of uninterruptible power systems have been developed to meet consumers\' requirements for continuity and quality of power for different types of loads over a wide range of power, from less than 100 W to several megawatts. Refer to annexes A and B for information on some of the types available. This standard applies to electronic uninterruptible power systems (UPS): delivering single- or three-phase fixed frequency a.c. output voltage; with energy storage device in the d.c. link if not otherwise specified; with rated voltage not exceeding 1 000 V a.c.; movable, stationary and/or fixed equipment. This standard also includes the method of specifying all power switches that form integral parts of a UPS and are associated with its output. Included are interrupters, bypass switches, isolating switches, load transfer switches and tie switches. These switches interact with other functional units of the UPS to maintain continuity of load power. This standard does not refer to conventional mains distribution boards, rectifier input switches or d.c. switches (for example for batteries, rectifier output or inverter input, etc.), or UPS based on rotating machines. NOTE 1 – This standard recognizes that the major market usage with the UPS ratings within its scope is in conjunction with information technology equipment. Under current technology, the majority of UPS load equipment employs power supplies which present a non-linear load to the UPS and can be tolerant of non-sinusoidal voltage waveforms for a limited time duration. UPS output ratings are specified to be compatible with non-linear loading and linear loading, subject to manufacturers\' declaration if different. References within this standard to linear loading are retained for test method reasons, or validation of manufacturers\' additional declaration. NOTE 2 – For use of UPS with a non-sinusoidal output voltage waveform, beyond the stored-energy time recommended in this standard, the agreement of the load equipment manufacturer should be sought. NOTE 3 – For UPS output frequencies other than 50 Hz or 60 Hz, performance specification is subject to agreement between manufacturer and purchaser. This standard is intended to define a complete uninterruptible power system in terms of its performance and not individual UPS functional units. The individual UPS functional units are dealt with in the IEC publications referred to in the bibliography given in annex I, which apply in so far as they are not in contradiction with this standard.