BS EN 50091-1-2:1999

Foreword
1 General
    1.1 Scope
    1.2 Normative references
    1.3 Definitions
    1.4 General requirements
    1.5 General conditions for tests
    1.6 Components
    1.7 Power interfaces
    1.8 Marking and instructions
2 Fundamental design requirements
    2.1 Protection against electric shock and energy hazards
    2.2 Insulation
    2.3 Safety Extra-Low Voltage (SELV) Circuits
    2.4 Limited current circuits
    2.5 Provisions for protective earthing
    2.6 A.C. and d.c. power isolation
    2.7 Overcurrent and earth fault protection
    2.8 Protection of service personnel
    2.9 Clearances, creepage distances and distances through
          insulation
    2.10 External signalling circuits
    2.11 Limited power source
    2.12 Protection of the applied load
    2.13 Connection to other equipment
3 Wiring, connections and supply
    3.1 General
    3.2 Connection to power sources
    3.3 Wiring terminals for external power conductors
4 Physical requirements
    4.1 Stability and mechanical hazards
    4.2 Mechanical strength and stress relief
    4.3 Construction details
    4.4 Resistance to fire
    4.5 Battery location
5 Thermal and electrical requirements
    5.1 Heating
    5.2 Earth leakage current
    5.3 Electric strength
    5.4 Abnormal operating and fault conditions
Annexes
A (normative) Test for resistance to heat and fire
B (normative) Motor test under abnormal conditions
C (normative) Transformers
D (normative) Measuring instruments for earth
    leakage current test
E (normative) Temperature rise of a winding
F (normative) Measurements of creepage
G (normative) Earth leakage current for UPS intended
    to be connected directly to IT power systems
H (informative) Guidance on protection against ingress
    of water and foreign objects
J (informative) Tables of electrochemical potentials
K (normative) Thermal controls
L (normative) Backfeed protection test
M (normative) Reference load conditions
N (normative) Ventilation of battery compartments
P (normative) Minimum and maximum cross-sections
Q (informative) A-Deviations
R (normative) Special national conditions

Applicable to electronic indirect a.c. convertor systems with an electrical energy storage device in the d.c. link. Main function of the UPS covered is to ensure continuity of an alternative power source. Uninterruptible power system may also serve to improve the quality of the power source by keeping it within specified characteristics. Applies to UPS for use on distribution systems up to 1 000 V a.c. which are movable, stationary, fixed and for building in; intended to be installed in restricted access locations and details requirements for safety of service personnel. To ensure the safety of installed UPS both as a single UPS unit or as a system of interconnected UPS units, subject to installing, operating and maintaining the UPS in the manner prescribed by the manufacturer.