CSA - CAN/CSA-E61558-1:12
Safety of power transformers, power supplies, reactors and similar products - Part 1: General requirements and tests
|Publication Date:||1 July 2012|
|ICS Code (Transformers. Reactors):||29.180|
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:
- for transformers, there is no change in frequency .However, transformers (e.g. constant voltage transformers) may have an internal resonance frequency not exceeding 30 kHz;
- for power supplies, the internal operational frequency and waveform are different from the supply frequency and waveform, and the internal operational frequency does not exceed 500 Hz (see definition 3.1.19);
- for switch mode power supplies, the internal operational frequency and waveform are different from the supply frequency and waveform and the internal operational frequency exceeds 500 Hz and does not exceed 100 MHz.
The relevant parts 2 may be found in the introduction of this standard.
a) Stationary or portable, single-phase or poly-phase, air-cooled (natural or forced), isolating and safety isolating transformers, independent or associated, not forming a part of distribution networks and with the following characteristics:
- rated supply voltage not exceeding 1 000 V a.c.;
- rated supply frequency not exceeding 500 Hz;
and complying with the following values, unless otherwise specified in the relevant part 2:
• for isolating transformers:
- rated output for single phase transformers, not exceeding 25 kVA, and for polyphase transformers not exceeding 40 kVA.
- no-load output voltage and the rated output voltage exceeding 50 V a.c., and not exceeding 500 V a.c, or 1 000 V a.c. to be in accordance with the National Wiring Rules or for a special application.
• for safety isolating transformers:
- rated output for single phase transformers not exceeding 10 kVA, and for polyphase transformers not exceeding 16 kVA.
- no-load output voltage and the rated output voltage not exceeding 50 V a.c. between conductors, or between any conductor and protective earth.
NOTE 1 Isolating and safety isolating transformers are used where double or reinforced insulation between circuits is required by the installation rules or by the appliance specification (for example toys, bells, portable tools, handlamps).