What is BS EN IEC 61558‑1 - Safety requirements of transformers about?
BS EN IEC 61558‑1 is the first part of an international multi-series standard that focuses on provisions and specifications for the safety of transformers, reactors, and power supply units along with their combinations.
BS EN IEC 61558‑1 deals with safety aspects of transformers, reactors, power supply units, and combinations thereof such as electrical, thermal, and mechanical safety. It covers the independent or associated stationary or portable types of dry-type transformers, power supply units, including switch-mode power supply units, reactors, and combinations thereof in the field of safety.
The windings can be encapsulated or non-encapsulated. They are not forming a part of the distribution network.
Note 1: BS EN IEC 61558‑1 also applies to transformers, power supply units, switch mode power supply units, and reactors incorporating electronic circuits.
Note 2: BS EN IEC 61558‑1 is applicable to transformers without limitation of the rated output subject to an agreement between the purchaser and the manufacturer.
Note 3: BS EN IEC 61558‑1 does not apply to external circuits and their components intended to be connected to the input or output terminals or socket-outlets of the transformers, power supply units and switch-mode power supply units, and reactors.
Who is BS EN IEC 61558‑1 - Safety requirements of transformers for?
BS EN IEC 61558‑1 on safety requirements of transformers is useful for:
- Manufacturers and suppliers of transformers
- Dealers and distributors of transformers
- Designers of transformers
- Test/ service providers for transformers
Why should you use BS EN IEC 61558‑1 - Safety requirements of transformers?
Transformer Protection is necessary in order to detect internal faults in the transformer with a high degree of sensitivity. Simultaneously, it should be immune to faults external as well so that fault detection can be done accurately.
BS EN IEC 61558‑1 covers safety requirements for transformers. The term transformer covers transformers, reactors, and power supply units in this standard. It considers the requirements and test provisions so that a transformer can be installed in accordance with the standard wiring rules.
BS EN IEC 61558‑1 recognizes the internationally accepted levels of protection against the possible electrical, mechanical, and fire hazards caused by transformers operating under normal conditions in accordance with the manufacturer's instructions. It also covers abnormal conditions which can occur during transformer operation. Its objective is to provide users with a set of requirements and tests considered to be generally applicable to most types of transformers.
What’s changed since the last update?
BS EN IEC 61558‑1:2019 supersedes BS EN 61558‑1:2005+A1:2009, which is withdrawn.
BS EN IEC 61558‑1:2019 includes the following significant technical changes with respect to the previous edition:
- Fully insulated winding wires (FIW), new tables and aging tests for FIW constructions, overvoltage categories 1, 2, 3, and 4 for clearances and dielectric strength tests (new tables) are included, development of new symbols for the different overvoltage categories
- The symbol for maximum altitudes, if higher than 2000 m, symbol for plug-in power supply units if the pins are damaged (tumbling barrel test), the symbol for minimum temperature (even during the transportation)
- Alternative temperature measurement, simulated load, and back-to-back method according to IEC 60076-11, short circuit and overload protection, simulated load, and back-to-back method according to IEC 60076-11, adjustment of temperatures according to CENELEC Guide 29
- Establishing partial discharge test above 750 V for FIW constructions, requirements for toroidal core constructions, division for basic and for supplementary isolation, modification of protection indexes for enclosures (IP-code)
- Dimensioning of rectangular cross-section connectors for transformers, repetition test, 80 % of required dielectric strength test voltage of Table 14, vibration test for vehicles and railway applications, two Y1 Capacitors for working voltages above 250 V and not exceeding 500 V with overvoltage category 3
