12 - 1 Scope
14 - 2 Normative references
16 - 3 Terms and definitions
17 - 3.1 Transformers
20 - 3.2 General terms
21 - 3.3 Operations and protections
23 - 3.4 Circuits and windings
23 - 3.5 Ratings
25 - 3.6 No-load values
25 - 3.7 Insulation
28 - 3.8 Touch current and protective earth conductor current
28 - 4 General requirements
29 - 5 General notes on tests
29 - 5.1 Tests according to this standard are:
31 - 6 Ratings
31 - 7 Classification
31 - 7.1 Transformers are classified:
31 - According to their protection against electric shock:
32 - 8 Marking and other information
32 - 8.1 Transformers shall be marked with the:
37 - 9 Protection against electric shock
37 - 9.1 Protection against contact with hazardous live parts
37 - 9.1.1 Determination of hazardous live parts
38 - 9.1.2 Accessibility to hazardous live parts
39 - 9.1.3 Accessibility to non hazardous live parts
39 - 9.2 Protection against hazardous electrical discharge
40 - 10 Change of input voltage setting
40 - 11 Output voltage and output current under load
41 - 12 No-load output voltage
41 - 13 Short-circuit voltage
41 - 14 Heating
41 - 14.1 General requirements
45 - 14.2 Application of 14.1 or 14.3 according to the insulation system
45 - 14.3 Accelerated ageing test for undeclared class of insulation system
47 - 15 Short circuit and overload protection
47 - 15.1 General
49 - 15.2 Inherently short-circuit proof transformers
49 - 15.3 Non-inherently short-circuit proof transformers
51 - 16 Mechanical strength
51 - 16.1 General
51 - 16.2 Stationary transformers
52 - 16.3 Portable transformers (except portable transformers with integral pins for introduction in socket-outlet in the fixed wiring)
52 - 16.4 Portable transformers provided with integral pins for introduction in socket-outlets of the fixed wiring
53 - 17 Protection against harmful ingress of dust, solid objects and moisture
53 - 17.1 Degrees of protection provided by enclosures (IP code)
56 - 17.2 Humidity treatment
57 - 18 Insulation resistance, dielectric strength and leakage current
57 - 18.1 General
57 - 18.2 Insulation resistance
57 - 18.3 Dielectric strength test
59 - 18.4 Insulation between and within windings
59 - 18.5 Touch current and protective earth conductor current
59 - 18.5.1 Touch current
60 - 18.5.2 Protective earth conductor current
60 - 19 Construction
67 - 20 Components
72 - 21 Internal wiring
73 - 22 Supply connection and other external flexible cables or cords
79 - 23 Terminals for external conductors
81 - 24 Provisions for protective earthing
82 - 25 Screws and connections
85 - 26 Creepage distances, clearances and distances through insulation
93 - Resistance to heat, fire and tracking
93 - 27.1 Resistance to heat
93 - 27.1.1 External accessible parts
93 - 27.1.2 Internal parts
94 - 27.2 Resistance to abnormal heat under fault conditions
95 - 27.3 Resistance to fire
95 - 27.3.1 External accessible parts
96 - 27.3.2 Internal parts
96 - 27.4 Resistance to tracking
96 - 28 Resistance to rusting