This part of IEC 60664 deals with insulation coordination for equipment having a rated voltage up to AC 1 000 V or DC 1 500 V connected to low-voltage supply systems.

This document applies to frequencies up to 30 kHz.

NOTE 1 Requirements for insulation coordination for equipment within low-voltage supply systems with rated frequencies above 30 kHz are given in IEC 60664-4.

NOTE 2 Higher voltages can exist in internal circuits of the equipment.

It applies to equipment for use up to 2 000 m above sea level and provides guidance for use at higher altitudes (See 5.2.3.4).

It provides requirements for technical committees to determine clearances, creepage distances and criteria for solid insulation. It includes methods of electrical testing with respect to insulation coordination.

The minimum clearances specified in this document do not apply where ionized gases are present. Special requirements for such situations can be specified at the discretion of the relevant technical committee.

This document does not deal with distances:

through liquid insulation;
through gases other than air;
through compressed air.

This basic safety publication focusing on safety essential requirements is primarily intended for use by technical committees in the preparation of standards in accordance with the principles laid down in IEC Guide 104 and ISO/IEC Guide 51.

One of the responsibilities of a technical committee is, wherever applicable, to make use of basic safety publications in the preparation of its publications.

However, in case of missing specified values for clearances, creepage distances and requirements for solid insulation in the relevant product standards, or even missing standards, this document applies.

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PDF Pages	PDF Title
2	undefined
5	Annex ZA(normative)Normative references to international publicationswith their corresponding European publications
8	English CONTENTS
12	FOREWORD
14	1 Scope 2 Normative references
15	3 Terms, definitions and abbreviated terms 3.1 Terms and definitions
21	3.2 Abbreviated terms 4 Basic technical characteristics for insulation coordination 4.1 General
22	4.2 Voltages 4.2.1 General aspects
23	4.2.2 Transient overvoltages
24	4.2.3 Temporary overvoltages 4.2.4 Recurring peak voltage
25	4.2.5 Steady-state working voltage 4.2.6 Steady-state peak voltage 4.3 Overvoltage categories 4.3.1 General 4.3.2 Equipment energized directly from the mains supply Figures Figure 1 – Recurring peak voltage
26	4.3.3 Systems and equipment not energized directly from the mains supply 4.4 Frequency 4.4.1 General 4.4.2 Solid insulation 4.5 Pollution 4.5.1 General
27	4.5.2 Degrees of pollution in the micro-environment 4.5.3 Conditions of conductive pollution 4.6 Insulating material 4.6.1 Solid insulation
28	4.6.2 Stresses
29	4.6.3 Comparative tracking index (CTI)
30	4.7 Environmental aspects 4.7.1 General 4.7.2 Altitude 4.7.3 Temperature 4.7.4 Vibrations 4.7.5 Humidity 4.8 Duration of voltage stress
31	4.9 Electrical field distribution 5 Design for insulation coordination 5.1 General 5.1.1 Means of insulation coordination 5.1.2 Frequency above 30 kHz 5.1.3 Reduced distances due to coating or potting 5.1.4 Equipment which are not connected to public low-voltage systems. 5.2 Dimensioning of clearances 5.2.1 General
32	5.2.2 Dimensioning criteria for clearances 5.2.3 Other factors involving clearances
33	5.2.4 Dimensioning of clearances of functional insulation 5.2.5 Dimensioning of clearances of basic insulation, supplementary insulation and reinforced insulation
34	5.3 Dimensioning of creepage distances 5.3.1 General
35	5.3.2 Dimensioning criteria of creepage distances
36	5.3.3 Other factors involving creepage distances
37	5.3.4 Dimensioning of creepage distances of functional insulation 5.3.5 Dimensioning of creepage distances of basic insulation, supplementary insulation and reinforced insulation Figure 2 – Determination of the width (W) and height (H) of a rib
38	5.4 Requirements for design of solid insulation 5.4.1 General 5.4.2 Voltage stress 5.4.3 Withstand of voltage stresses
40	5.4.4 Withstand on environmental stresses 6 Tests and measurements 6.1 General
41	6.2 Verification of clearances 6.2.1 General 6.2.2 Test voltages
43	6.3 Verification of creepage distances 6.4 Verification of solid insulation 6.4.1 General
44	6.4.2 Selection of tests
45	6.4.3 Conditioning 6.4.4 Impulse voltage test
46	6.4.5 AC power frequency voltage test 6.4.6 Partial discharge test
48	6.4.7 DC voltage test Figure 3 – Test voltages
49	6.4.8 High-frequency voltage test 6.5 Performing dielectric tests on complete equipment 6.5.1 General 6.5.2 Parts to be tested
50	6.5.3 Preparation of equipment circuits 6.5.4 Test voltage values 6.5.5 Test criteria 6.6 Other tests 6.6.1 Test for purposes other than insulation coordination 6.6.2 Sampling and routine tests 6.6.3 Measurement accuracy of test parameters
51	6.7 Measurement of the attenuation of the transient overvoltages 6.8 Measurement of clearances and creepage distances
52	Figure 4 – Across the groove Tables Table 1 – Dimensioning of grooves
53	Figure 5 – Contour of the groove Figure 6 – Contour of the groove with angle Figure 7 – Contour of rib
54	Figure 8 – Uncemented joint with grooves less than X Figure 9 – Uncemented joint with grooves equal to or more than X
55	Figure 10 – Uncemented joint with a groove on one side less than X Figure 11 – Creepage distance and clearance through an uncemented joint Figure 12 – Creepage distance and clearance to a head of screw more than X
56	Figure 13 – Creepage distance and clearance to a head of screw less than X Figure 14 – Creepage distance and clearance with conductive floating part
57	Annexes Annex A (informative) Basic data on withstand characteristics of clearances Table A.1 – Withstand voltages for an altitude of 2 000 m above sea level (1 of 2)
58	Table A.2 – Altitude correction factors for clearance correction
59	Figure A.1 – Withstand voltage at 2 000 m above sea level
60	Figure A.2 – Experimental data measured at approximately sea level and their low limits for inhomogeneous field
61	Figure A.3 – Experimental data measured at approximately sea level and their low limits for homogeneous field
62	Annex B (informative) Nominal voltages of mains supply for different modes of overvoltage control Table B.1 – Inherent control or equivalent protective control
63	Table B.2 – Cases where protective control is necessary and control is provided by surge protective device having a ratio of voltage protection level to rated voltagenot smaller than that specified in IEC 61643 (all parts)
64	Annex C (normative) Partial discharge test methods C.1 Test circuits C.1.1 General C.1.2 Test circuit for earthed test specimen (Figure C.1) Figure C.1 – Earthed test specimen
65	C.1.3 Test circuit for unearthed test specimen (Figure C.2) C.1.4 Selection criteria C.1.5 Measuring impedance C.1.6 Coupling capacitor Ck C.1.7 Filter C.2 Test parameters C.2.1 General Figure C.2 – Unearthed test specimen
66	C.2.2 Requirements for the test voltage C.2.3 Climatic conditions C.3 Requirements for measuring instruments C.3.1 General C.3.2 Classification of PD meters
67	C.3.3 Bandwidth of the test circuit C.4 Calibration C.4.1 Calibration of discharge magnitude before the noise level measurement
68	C.4.2 Verification of the noise level Figure C.3 – Calibration for earthed test specimen Figure C.4 – Calibration for unearthed test specimen
69	C.4.3 Calibration for the PD test C.4.4 Calibration pulse generator
70	Annex D (informative) Additional information on partial discharge test methods D.1 Measurement of partial discharge (PD), PD inception and extinction voltage D.2 Description of PD test circuits (Figure D.1) Figure D.1 – Partial discharge test circuits
71	D.3 Precautions for reduction of noise D.3.1 General D.3.2 Sources in the non-energized test circuit D.3.3 Sources in the energized test circuit D.3.4 Measures for reduction of noise D.4 Application of multiplying factors for test voltages D.4.1 General
72	D.4.2 Example 1 (circuit connected to mains supply) D.4.3 Example 2 (internal circuit with maximum recurring peak voltage Urp)
73	Annex E (informative) Comparison of creepage distances specified in Table F.5 and clearances in Table A.1 Figure E.1 – Comparison between creepage distances specifiedin Table F.5 and clearances in Table A.1
74	Annex F (normative) Tables Table F.1 – Rated impulse withstand voltage for equipment energized directly from the mains supply
75	Table F.2 – Clearances to withstand transient overvoltages
76	Table F.3 – Single-phase three-wire or two-wire AC or DC systems
77	Table F.4 – Three-phase four-wire or three-wire AC systems
78	Table F.5 – Creepage distances to avoid failure due to tracking (1 of 2)
80	Table F.6 – Test voltages for verifying clearances only at different altitudes Table F.7 – Severities for conditioning of solid insulation
81	Table F.8 – Dimensioning of clearances to withstand steady-state peak voltages, temporary overvoltages or recurring peak voltages b Table F.9 – Additional information concerning the dimensioning of clearances to avoid partial discharge
82	Table F.10 – Altitude correction factors for clearance correction
83	Annex G (informative) Determination of clearance distances according to 5.2 Figure G.1 – Determination of clearance distances according to 5.2 (1 of 2)
85	Annex H (informative) Determination of creepage distances according to 5.3 Figure H.1 – Determination of creepage distances according to 5.3 (1 of 2)
87	Bibliography

Published By	Publication Date	Number of Pages
BSI	2020	88


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Status	Revision Underway
Title	Insulation coordination for equipment within low-voltage supply systems – Principles, requirements and tests
Corrects	BS EN IEC 60664-1:2020
Replaces	BS EN 60664-1:2007
Publisher	BSI
Committee	GEL/109
Pages	88
Publication Date	2020-12-16
ISBN	978 0 539 15877 9
Standard Number	BS EN IEC 60664-1:2020
Identical National Standard Of	IEC 60664-1:2020/COR1:2020, EN IEC 60664-1:2020/AC:2020-12, IEC 60664-1:2020/COR1:2020
Descriptors	Low-voltage equipment, Electrical insulating materials, Clearances, Rated voltage, Dimensions, Electrical equipment, Electrical testing, Leakage paths, Electrical insulation, Overvoltage, Withstand voltage, Coordination, Impulse voltages, Electrical installations, Clearance distances, Solid electrical insulating materials
ICS Codes	29.080.30 - Insulation systems

BS EN IEC 60664-1:2020

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