IEC 60950-22:2016 pdf download.Information technology equipment- Safety
4.2.2 Mains transient voltage on AC mains supply
Equipment that is part of the building installation, or that may be subject to transient overvoltages exceeding those for overvoltage category II, shall be designed for overvoltage category II or IV, unless additional protection is to be provided internally or externally to the equipment. In this case, the installation instructions shall state the need for such additional protection. Clearances in equipment designed for overvoltage category III or IV shall comply with Annex G of IEC 60950-1:2005. The insulation system used in such equipment shall be capable of withstanding the test voltage given in Table 5C of IEC 60950-1:2005/AMD2:2013.
4.2.3 Mains transient voltage on DC mains supply
The transient on a D.C. MAINS SUPPLY depends on the source and the installation of the D.C. MAINS SUPPLY. When determining the D.C. MAINS TRANSIENT VOLTAGE，the installation and the source of the D.C. MAINS shall be taken into account. If these are not known, the MAINS TRANSIENT VOLTAGE on the D.C. MAINS SUPPLY shall be assumed to be 1,5 kV. The manufacturer shall declare the MAINS TRANSIENT VOLTAGE on the D.C. MAINS SUPPLY in the installation instructions.
4.3 Rise of earth potential
Attention is drawn to the fact that during fault clearing conditions, HAZARDOUS VOLTAGES may exist and be accessible for longer periods than for indoor equipment and special earthing conditions may be necessary. These are typically specified in local installation codes.
NOTE In the USA, these requirements are contained in the National Electrical Code. In Canada, they are contained in the Canadian Electrical Code.
Compliance is checked by evaluation of the installation instructions.
5 Marking and instructions
The installation instructions for OUTDOOR EQUIPMENT shall include details of any special features needed for protection from conditions in the OUTDOOR LOCATION (see 1.7.2 of IEC 60950-1:2005).
If a manufacturer of an OUTDOOR ENCLOSURE classifies a product in accordance with IEC 60529, the IP code shall be declared, however it is not required to mark the IP code on the OUTDOOR ENCLOSURE. It is not required to make such a declaration for OUTDOOR EQUIPMENT.
Compliance is checked by inspection.
8.1 General
Protection against corrosion shall be provided by the use of suitable materials or by the application of a protective coating applied to the exposed surface, taking into account the intended conditions of use.
Parts, such as dials or connectors, that serve as a functional part of an OUTDOOR ENCLOSURE shall comply with the same environmental protection requirements as for the OUTDOOR ENCLOSURE.
NOTE 1 Aspects affecting safety which require the integrity of the OUTDOOR ENCLOSURE through the life of the product include:
- continued protection against access to hazardous parts, including after mechanical strength tests;
- continued protection against ingress of dust and water;
- continued provision of earth continuity.
An OUTDOOR ENCLOSURE shall not be used to carry current during normal operation if this could cause corrosion that would impair safety. This does not preclude connection of a conductive part of an OUTDOOR ENCLOSURE to protective earth for the purpose of carrying fault
currents.IEC 60950-22 pdf download.