IEC TS 62257-4:2015(E) provides a method for describing the results to be achieved by the electrification system independently of the technical solutions that could be implemented. The purpose is to provide a method to assist project contractors and project developers to select and design the electrification system for isolated sites while matching the identified needs, such as those described in IEC TS 62257-2. The main technical changes with regard to the previous edition are as follows:
1.1
This Standard applies to exit signs, unit equipment, emergency luminaires, and central power systems intended for connection to circuits with nominal voltages of 600 V and less and providing illumination in the event of a failure of the normal power supply for nonhazardous locations in accordance with the Rules of the Canadian Electrical Code, Part I.
1.2
This Standard includes requirements for the construction of emergency lighting equipment to preclude fire and shock hazards and to ensure that the equipment has the minimum capability for performing its intended function.
1.3
In this Standard, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard.
Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.
Notes to tables and figures are considered part of the table or figure and may be written as requirements.
Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.
1.4
The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.
This International Standard deals with safety aspects of power transformers, power supplies, reactors and similar products such as electrical, thermal and mechanical safety.
This standard covers the following types of dry-type transformers, power supplies, including switch mode power supplies, and reactors, the windings of which may be encapsulated or non-encapsulated :
NOTE 1 The distinction between transformers, power supplies and switch mode power supplies is as follows:
Replacement:
This part 2 of IEC 61558 applies to stationary or portable, single-phase or polyphase, aircooled separating transformers, associated or not, having a rated supply voltage not exceeding 1000 V a.c., a rated frequency not exceeding 500 Hz, and a rated output not exceeding: . 1 kVA for single-phase transformers; . 5 kVA for polyphase transformers.
Replacement:
This part 2-2 of IEC 61558 applies to stationary or portable, single-phase or poly-phases, aircooled control transformers associated or otherwise having a rated supply voltage not exceeding 1 000 V a.c. or 1 415 V ripple free d.c. and rated frequency not exceeding 500 Hz and no limitation of the rated output.
This standard is applicable to transformers used between circuits where double or reinforced insulation is not required by the installation rules or by the equipment specification.
Replacement:
This part 2 of IEC 61558 applies to stationary or portable, single-phase or polyphase, air-cooled isolating transformers, associated or otherwise, having a rated supply voltage not exceeding 1000 V a.c. and rated frequency not exceeding 500 Hz, the rated output not exceeding: - 25 kVA for single-phase transformers; - 40 kVA for polyphase transformers.
