SN EN 60255-27 : 2005

INTRODUCTION
1 Scope and object
2 Normative references
3 Terms and definitions
4 General safety requirements
   4.1 Earthing requirements (grounding, earthing
        and screening)
5 Protection against electric shock
   5.1 Requirements for protection against electric
       shock
   5.2 Single-fault conditions
6 Mechanical aspects
   6.1 Protection against mechanical hazards
   6.2 Mechanical requirements
   6.3 Mechanical security of terminations
7 Flammability and resistance to fire
   7.1 General
   7.2 General hazards from overheating and fire
   7.3 Minimization of fire risk
   7.4 Cabling and fusing
   7.5 Flammability of materials and components
   7.6 Fire ignition sources
   7.7 Conditions for a fire enclosure
   7.8 Requirements for primary circuits and circuits
        exceeding ELV limits
   7.9 Fire enclosures and flame barriers
   7.10 Assessment of the fire risk due to a
        single-fault condition
   7.11 Limited-energy circuit
8 General and fundamental design requirements for
   safety
   8.1 Climatic conditions for safety
   8.2 Electrical connections
   8.3 Components
   8.4 Connection to communication networks
   8.5 Connection to other equipment
   8.6 Laser sources
   8.7 Explosion
9 Marking, documentation and packaging
   9.1 Marking
   9.2 Documentation
   9.3 Packaging
10 Type tests and routine tests
   10.1 Safety type tests
   10.2 Routine testing or sample testing
   10.3 Conditions for testing
   10.4 Verification procedure
   10.5 Tests
Annex A (normative) Isolation class requirements
                       and example diagrams
Annex B (informative) Nominal voltages of supply systems
Annex C (normative) Rated impulse voltages
Annex D (normative) Guidance for the determination of
                       clearance, creepage distance and
                       withstand voltages
Annex E (informative) Measurement of creepage distances
                       and clearances
Annex F (normative) Standard test fingers
Annex G (informative) Guidance for impulse voltage test
Annex H (informative) Components
Annex I (informative) Safe maximum short-term voltage
                       duration and capacitor size
                       under a single-fault condition
Annex J (informative) External wiring terminations
Annex K (informative) Examples of battery protection
Annex L (informative) Reasons why functional safety is
                       excluded from the scope of
                       IEC 60255-27
Bibliography
Annex ZA (normative) Normative references to international
                       publications with their corresponding
                       European publications

Specifies the product safety requirements for measuring relays and protection equipment having a rated a.c. voltage up to 1000 V with a rated frequency up to 65 Hz, or a rated d.c. voltage up to 1500 V.