IEC 60364-5-56:2018 covers general requirements for safety services, selection and erection of electrical supply systems for safety services and electrical safety sources. Standby electrical supply systems are outside the scope of this part. This part does not apply to installations in hazardous areas (BE3), for which requirements are given in IEC 60079-14. This third edition cancels and replaces the second edition published in 2009. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
1) Modifications to normative references and terms and definitions.
2) Under electrical circuits for safety services, addition of requirements concerning circuit and overcurrent protection in order to maintain reliability of safety service power supplies under fire conditions.
3) Under electrical circuits for safety services, addition of requirements stating that circuits for safety services are not to be protected by RCDs or AFDDs.
4) Under emergency lighting applications, addition of requirements to prevent emergency lighting systems being adversely affected by any control system.
5) Addition of requirements for all emergency luminaires in the area to provide full design light output in the event of any final circuit failure.
6) Addition of a new Annex D (informative): Fire switch.
7) Addition of a new Annex E (informative): Example of installation methods of safety services with cable management system.
8) Addition of a new Annex F (informative): Wiring systems.
9) Addition of a new Annex G (informative): Guidance on suitable locations for electrical sources for safety services.