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eLibrary > BS EN IEC 61558-1:2019 Safety of transformers, reactors, power supply units and combinations thereof - General requirements and tests >

BS EN IEC 61558-1:2019 Safety of transformers, reactors, power supply units and combinations thereof - General requirements and tests, 2026

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BS EN IEC 61558-1:2019 Safety of transformers, reactors, power supply units and combinations thereof - General requirements and tests, 2026

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Annex ZA(normative)Normative references to international publicationswith their corresponding European publications
Annex ZZ(informative)Relationship between this European standard and the safety objectives of Directive 2014/35/EU [2014 OJ L96] aimed to be covered
English [Go to Page]
CONTENTS
FOREWORD
INTRODUCTION
Figures [Go to Page]
Figure 1 – IEC 61558 principle
1 Scope
2 Normative references
3 Terms and definitions [Go to Page]
3.1 Transformers
3.2 General terms
3.3 Operations and protections
3.4 Circuits and windings
3.5 Ratings
3.6 No-load values
3.7 Insulation
3.8 Touch current and protective earthing conductor current
4 General requirements
5 General notes on tests [Go to Page]
Figure 2 – Mounting box for flush-type transformer
6 Ratings
7 Classification
8 Marking and other information
Tables [Go to Page]
Table 1 – Symbols used on equipment or in instructions
9 Protection against electric shock [Go to Page]
9.1 General
9.2 Protection against contact with hazardous-live-parts [Go to Page]
9.2.1 Determination of hazardous-live-parts
9.2.2 Accessibility to hazardous-live-parts
Figure 3 – Test pin (see IEC 61032, test probe 13)
Figure 4 – Standard test finger (see IEC 61032, test probe B) [Go to Page]
9.2.3 Accessibility to non hazardous-live-part
9.3 Protection against hazardous electrical discharge
10 Change of input voltage setting
11 Output voltage and output current under load
12 No-load output voltage
13 Short-circuit voltage
14 Heating [Go to Page]
14.1 General requirements [Go to Page]
14.1.1 Temperature-rise test
14.1.2 Alternative temperature-rise test
Figure 5 – Example of back-to-back method – Single phase
Figure 6 – Example of back-to-back method – Three phase [Go to Page]
14.1.3 Determination of steady-state conditions
Table 2 – Values of maximum temperatures in normal use
14.2 Application of 14.1 or 14.3 according to the insulation system
Table 3 – Explanation of the maximum winding temperatures required in Table 2
14.3 Accelerated ageing test for undeclared class of insulation system [Go to Page]
14.3.1 General
14.3.2 Heat run
Table 4 – Test temperature and testing time (in days) per cycle [Go to Page]
14.3.3 Vibration
14.3.4 Moisture treatment
14.3.5 Measurements
15 Short circuit and overload protection [Go to Page]
15.1 General requirements [Go to Page]
15.1.1 Short circuit and overload test method
Table 5 – Maximum values of temperatures under short-circuitor overload conditions [Go to Page]
15.1.2 Alternative short circuit and overload test method
15.2 Inherently short-circuit proof transformers
15.3 Non-inherently short-circuit proof transformers
Table 6 – Values of T and k for fuses
15.4 Non-short-circuit proof transformers
15.5 Fail-safe transformers
16 Mechanical strength [Go to Page]
16.1 General
16.2 Stationary transformers
16.3 Portable transformers (except portable transformers with integral pins for introduction in socket-outlet in the fixed wiring)
16.4 Portable transformers provided with integral pins for introduction in socket-outlets of the fixed wiring [Go to Page]
16.4.1 General requirements
16.4.2 Portable transformers provided with integral pins according to EN 50075 (IEC plug type C) for introduction in socket-outlets of the fixed wiring
Table 7 – Pull force on pins
16.5 Additional requirements for transformers to be used in vehicles and railway applications [Go to Page]
16.5.1 Transformers to be used in vehicles and railway applications
Table 8 – Conditions for vibration testing (random)
Table 9 – Amplitude spectrum density ASD values for accelerated life testing [Go to Page]
16.5.2 Test requirements for the transportation of transformers
Figure 7 – Amplitude spectrum density for random testing
Table 10 – Frequency values depending on the weight of the specimen
Table 11 – Excitation values for vibration testing
17 Protection against harmful ingress of dust, solid objects and moisture [Go to Page]
17.1 Degrees of protection provided by enclosures (IP code) [Go to Page]
17.1.1 General requirements
Figure 8 – Normalised spectrum of shock [Go to Page]
17.1.2 Tests on transformers with enclosure
Table 12 – Solid-object-proof transformer test
17.2 Humidity treatment
18 Insulation resistance, dielectric strength and leakage current [Go to Page]
18.1 General
18.2 Insulation resistance
18.3 Dielectric strength test
Table 13 – Values of insulation resistance
Table 14 – Table of dielectric strength test voltages
18.4 Insulation between and within windings
18.5 Touch current and protective earthing conductor current [Go to Page]
18.5.1 General
Figure 9 – Test voltage sequence [Go to Page]
18.5.2 Touch current
18.5.3 Protective earthing conductor current
Figure 10 – Test configuration: single-phase equipment on star TN or TT system
Table 15 – Limits for currents
19 Construction [Go to Page]
19.1 General construction [Go to Page]
19.1.1 General
19.1.2 Auto-transformers
19.1.3 Separating transformers
19.1.4 Isolating transformers and safety isolating transformers
19.2 Flammability of materials
19.4 Class II transformer contact prevention of accessible conductive parts
19.5 Class II transformer insulation reassembling after service
19.6 Loosening of wires, screws or similar parts
19.7 Resistor or capacitor connection with accessible conductive parts
19.8 Bridging of separated conductive parts by resistors or capacitors
19.9 Insulating material separating input and output windings
19.10 Accidental contact protection against hazardous-live-parts provided by isolating coating
19.11 Insulating material of handles, operating levers, knobs and similar parts
19.12 Winding construction
Figure 11 – Abrasion resistance test for insulating coated layers
Blank Page [Go to Page]
[Go to Page]
19.13 Fixing of handles, operating levers and similar parts
19.14 Fixing of covers providing protection against electric shock
19.15 Strain on fixed socket-outlets caused by pin-transformers connection
19.16 Portable transformers for use in irregular or harsh conditions
19.17 Drain hole of transformers protected against ingress of water
19.18 Plug connected transformers protected against ingress of water
19.19 Flexible cable or flexible cord connection for class I portable transformers
19.20 SELV- and PELV-circuit separation of live parts
19.21 Protection against contact for FELV-circuit
19.22 Protective earthing regarding class II transformers
19.23 Protective earthing regarding class III transformers
20 Components
21 Internal wiring
22 Supply connection and other external flexible cables or cords [Go to Page]
Table 16 – Nominal cross-sectional areas of external flexible cables or cords
Figure 12 – Flexing test apparatus
Table 17 – Pull and torque to be applied to external flexible cables or cords fixed to stationary and portable transformers
23 Terminals for external conductors
24 Provisions for protective earthing
25 Screws and connections [Go to Page]
Table 18 – Torque to be applied to screws and connections
26 Creepage distances, clearances and distances through insulation [Go to Page]
26.1 General
Table 19 – Torque test on glands
26.2 Creepage distances and clearances [Go to Page]
26.2.1 General
26.2.2 Windings covered with adhesive tape
26.2.3 Uncemented insulationing parts
26.2.4 Cemented insulating parts
26.2.5 Enclosed parts (e.g. by impregnation or potting)
26.3 Distance through insulation
Figure 13 – Test arrangement for checking mechanical withstanding of insulating materials in thin sheet layers
Table 20 – Clearances in mm
Table 21 – Creepage distances in mm
Table 22 – Distance through insulation in mm
Table 23 – Creepage distances and clearance between terminals for external connection
Table 24 – Values of FIW wires with minimum overall diameter and minimum test voltages according to the total enamel increase
27 Resistance to heat, fire and tracking [Go to Page]
27.1 General
27.2 Resistance to heat [Go to Page]
27.2.1 General
27.2.2 External accessible parts
Figure 14 – Ball-pressure apparatus [Go to Page]
27.2.3 Internal parts
27.3 Resistance to abnormal heat under fault conditions
27.4 Resistance to fire [Go to Page]
27.4.1 General
27.4.2 External accessible parts
27.4.3 Internal parts
27.5 Resistance to tracking
28 Resistance to rusting
Annexes [Go to Page]
Annex A (normative) Measurement of creepage distances and clearances
Figure A.1 – Example 1
Table A.1 – Width of groove values depending on the pollution degree
Figure A.2 – Example 2
Figure A.3 – Example 3
Figure A.4 – Example 4
Figure A.5 – Example 5
Figure A.6 – Example 6
Figure A.7 – Example 7
Figure A.8 – Example 8
Annex B (normative) Testing a series of transformers [Go to Page]
B.1 General
B.2 Requirements
B.3 Constructional inspection
Annex C (void)
Annex D (void)
Annex E (normative) Glow-wire test [Go to Page]
E.1 General
E.2 Severity
E.3 Conditioning
E.4 Test procedure
Annex F (normative) Requirements for manually operated switches which are parts of transformers assembly [Go to Page]
F.1 General
F.2 Switches tested as a separate component
F.3 Switches tested as part of the transformer
Table F.1 – Peak surge current of additional loads
Annex G (normative) Tracking test [Go to Page]
G.1 General
G.2 Test specimen
G.3 Test apparatus
G.4 Procedure
Annex H (normative) Electronic circuits [Go to Page]
H.1 General
H.2 General notes on tests (addition to Clause 5)
H.3 Short circuit and overload protection (addition to Clause 15)
H.4 Creepage distances, clearances and distances through insulation (addition to Clause 26)
Figure H.1 – Example of an electronic circuit with low-power points
Annex I (informative) Dimensions for rectangular cross-section connectors of transformers, basic dimensions and coordination
Table I.1 – Dimensions of rectangular copper connectors
Annex J (normative) Measuring network for touch-currents
Figure J.1 – Measuring network for touch-current
Annex K (normative) Insulated winding wires [Go to Page]
K.1 General
K.2 Type tests [Go to Page]
K.2.1 General
K.2.2 Dielectric strength test
K.2.3 Flexibility and adherence
K.2.4 Heat shock
K.2.5 Retention of dielectric strength after bending
Table K.1 – Mandrel diameter
Table K.2 – Oven temperature [Go to Page]
K.3 Testing during manufacturing [Go to Page]
K.3.1 General
K.3.2 Routine test
K.3.3 Sampling test
Annex L (normative) Routine tests (production tests) [Go to Page]
L.1 General
L.2 Protective earthing continuity test
L.3 Checking of no-load output voltage
L.4 Dielectric strength test
L.5 Checking of protective devices mounting
L.6 Visual inspection
L.7 Repetition test after routine dielectric strength test
Annex M (informative) Examples to be used as a guide for 19.1 [Go to Page]
M.1 General
M.2 Coil-former [Go to Page]
M.2.1 Concentric type
Figure M.1 – Examples for concentric type constructions [Go to Page]
[Go to Page]
M.2.2 Side-by-side type
M.3 Windings [Go to Page]
M.3.1 Without screen
Figure M.2 – Examples for side-by-side type constructions
Figure M.3 – Examples for winding constructions without screen [Go to Page]
[Go to Page]
M.3.2 With screen
Figure M.4 – Examples for wrapped winding constructions
Figure M.5 – Examples for winding constructions with screen
Annex N (informative) Examples for checking points of dielectric strength test voltages
Figure N.2 – Transformer of class II construction with metal enclosure
Figure N.3 – Transformer of class II construction with enclosure of insulating material
Annex O (void)
Annex P (informative) Examples for measurement points of creepage distances and clearances
Figure P.1 – Transformer of class I construction
Figure P.2 – Transformer of class I construction with earthed metal screen
Figure P.3 – Transformer of class II construction with metal enclosure
Figure P.4 – Transformer of class II construction with enclosure of insulating material
Annex Q (informative) Explanation of IP numbers for degrees of protection [Go to Page]
Q.1 General
Q.2 Degrees of protection against access to hazardous parts and against solid foreign objects
Table Q.1 – Degrees of protection against access to hazardous parts indicated by the first characteristic numeral
Table Q.2 – Degrees of protection against solid foreign objects indicated by the first characteristic numeral [Go to Page]
Q.3 Degrees of protection against ingress of water
Table Q.3 – Degrees of protection indicated by the second characteristic numeral
Annex R (normative) Explanations of the application of 6.1.2.2.1 of IEC 60664-1:2007 [Go to Page]
R.1 Impulse dielectric test
R.2 Example
Table R.1 – Impulse test voltage according to 6.1.2.2.1 of IEC 60664-1:2007
Annex S (void)
Annex T (void)
Annex U (void)
Annex V (informative) Symbols to be used for thermal cut-outs [Go to Page]
V.1 General
V.2 Non-self-resetting thermal cut-out (see 3.3.4)
V.3 Self-resetting thermal cut-out (see 3.3.3)
Figure V.1 – Restored by manual operation
Figure V.2 – Restored by disconnection of the supply
Figure V.3 – Thermal link (see 3.3.5)
Figure V.4 – Self-resetting thermal cut-out
Annex W (normative) Coated printed circuit boards [Go to Page]
W.1 Preamble
W.2 General
W.3 Cold
W.4 Rapid change of temperature
W.5 Additional tests
Bibliography
Index of defined terms [Go to Page]

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