AS/NZS 61558.2.8:2001

1 - AS/NZS 61558.2.8:2001 SAFETY OF POWER TRANSFORMERS, POWER SUPPLY UNITS AND SIMILAR - PARTICULAR REQUIREMENTS FOR BELL AND ...
4 - CONTENTS
5 - PREFACE
7 - 1 Scope
7 - 2 Normative references
8 - 3 Definitions
8 - 4 General requirements
8 - 5 General notes on tests
8 - 6 Ratings
9 - 7 Classification
9 - 8 Marking and other information
10 - 9 Protection against accessibility to hazardous live parts
10 - 10 Change of input voltage setting
10 - 11 Output voltage and output current under load
11 - 12 No-load output voltage
11 - 13 Short-circuit voltage
11 - 14 Heating
12 - 15 Short-circuit and overload protection
12 - 16 Mechanical strength
12 - 17 Protection against harmful ingress of dust, solid objects and moisture
12 - 18 Insulation resistance and dielectric strength
12 - 19 Construction
14 - 20 Components
14 - 21 Internal wiring
14 - 22 Supply connections and other external flexible cords
14 - 23 Terminals for external conductors
15 - 24 Provision for protective earthing
15 - 25 Screws and connections
15 - 26 Creepage distances, clearances and distances through insulation
15 - 27 Resistance to heat, abnormal heat, fire and tracking
15 - 28 Resistance to rusting
16 - Annexes
16 - Annex C - Material group II
16 - Annex D - Material group I

Specifies general safety requirements for approval and test purposes for bell and chime transformers. This Standard is an adotpion with national modifications and contains the full text of IEC 61558-2-8:1998.

Replacement:This international standard deals with all aspects of safety such as electrical, thermal and mechanical.This part 2-8 of IEC 61558 AS/NZS 61558 applies to fixed, single-phase, air-cooled (natural or forced), independent or associated safety isolating transformers for bell and chimes, having a rated supply voltage not exceeding 250 V a.c., a rated frequency not exceeding 500 Hz, a rated output not exceeding 100 VA.The no-load output voltage shall not exceed 33 V a.c. or 46 V ripple free d.c. and the rated output voltage shall not exceed 24 V a.c. or 33 V ripple free d.c.Bell and chime transformers are generally intended to supply domestic sound signalling equipment and other similar devices where the load is applied for short periods of time.NOTE 1 A partial load may be applied for illumination purposes.This standard applies to special safety isolating transformers (transformer for bell and chime) which are used where double or reinforced insulation between circuits is required by the installation rules or by the appliance specification.This standard is applicable to dry-type transformers. The windings may be encapsulated or non-encapsulated.NOTE 2 Attention is drawn to the fact that for transformers intended to be used in tropical countries special requirements may be necessary.NOTE 2. for the purposes of this standard, Australia and New Zealand are not considered to be tropical;This standard also applies to transformers incorporating electronic circuits. This standard does not apply to external circuits and their components intended to be connected to the input and output terminals or socket-outlets of the transformer.

AS 3108 first published in Australia in part as AS C126-1939.
Second edition 1958.
AS C167 first published 1962.
Revised and redesignated AS 3167-1981 (withdrawn 1987).
AS C126-1958 revised and redesignated AS 3126-1981 (withdrawn 1989).
AS 3126-1981 and AS 3167-1981 were revised and redesignated AS 3108.1-1984, AS 3108.2-1984 and AS 3108.3-1984.
Revised, amalgamated and redesignated AS 3108-1990.
First published in New Zealand as NZS/AS 3108:1990.
Jointly revised and designated Joint Standard AS/NZS 3108:1994.
Jointly revised and redesignated in part as AS/NZS 61558.2.8:2001.