NEN EN 50091-1 : 1994

Cooperating organizations
National foreword
Foreword
1 General
1.1 Scope
1.2 Definitions
1.3 General requirements
1.4 General conditions for tests
1.5 Components
1.6 Power interface
1.7 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)
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 personnel - safety interlocks
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
3 Wiring, connections and supply
3.1 General
3.2 Connection to power
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 currents
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 distances and
      clearances
G (normative) Earth leakage current for equipment
      intended to be connected directly to IT power
      systems
H (informative) Guidance on protection against
      ingress of water and foreign objects
J (informative) Table of electrochemical potentials
K (normative) Thermal controls
L (normative) Backfeed protection test
M (normative) Examples of normal load conditions
N (normative) Ventilation of battery compartments
P (normative) Normative references to International
      Publications
Q (informative) A-Deviations
National annex NA (informative) Committees responsible
National annex NB (informative) Cross-references

Applies to uninterruptable power system (UPS) meant to be installed in any operator accessible area. Specifies requirements to ensure safety for the operator and layman who may come into contact with the equipment and, where specifically stated, for service personnel. Applies to movable, stationary, fixed and built in UPS for distribution systems up to 1000 V a.c. Does not cover: UPS meant to be installed in separated electrical installations; d.c. supplied electronic ballasts; UPS based on rotating machines. Includes the following sections; fundamental design requirements; physical requirements; thermal and electrical requirements. Also gives detailed definitions and annexes.