IEC 61950:2019

IEC 61950 ®
Edition 3.0 2019-09
INTERNATIONAL
STANDARD
Cable management systems –
Specifications for extra-heavy-duty electrical steel conduit fittings and
accessories
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IEC 61950 ®
Edition 3.0 2019-09
INTERNATIONAL
STANDARD
Cable management systems –
Specifications for extra-heavy-duty electrical steel conduit fittings and

accessories
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.10 ISBN 978-2-8322-7373-9

– 2 – IEC 61950:2019 © IEC 2019
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 General requirements . 12
4.1 Tests . 12
4.2 Metallic materials . 12
4.2.1 General . 12
4.2.2 Corrosion protection . 12
4.3 Non-metallic materials . 13
4.3.1 Flammability . 13
4.3.2 Materials for bushings and insulating liners . 13
4.3.3 Elastomeric materials . 14
4.3.4 Gasket materials. 14
4.4 Construction . 15
4.4.1 Threads for fittings and conduit bodies . 15
4.4.2 Offset and angle fittings . 15
4.5 Screws . 16
4.6 Locknuts . 16
4.6.1 Construction . 16
4.6.2 Functional requirements for fitting locknuts . 17
4.7 Classifications . 17
4.7.1 Concrete-tight type . 17
4.7.2 Wet-location type . 19
4.7.3 Expansion, expansion-deflection, deflection fitting . 20
5 Fittings for EHDERS systems . 20
5.1 Types. 20
5.2 Fittings for threaded EHDERS conduit . 20
5.2.1 End stop . 20
5.2.2 Torque test . 20
5.2.3 Earth fault . 21
5.2.4 Threaded reducers . 22
5.3 Fittings for unthreaded EHDERS conduit . 22
5.3.1 Electrical continuity and mechanical strength . 22
5.3.2 Earth fault . 23
5.3.3 Construction . 23
5.4 Bushings . 24
5.4.1 General . 24
5.4.2 Thermoplastic or thermosetting materials . 24
5.5 Service-entrance heads . 24
5.5.1 End stops for service-entrance heads . 24
5.5.2 Assembly . 24
5.5.3 Openings . 24
5.5.4 Continuity test . 25
5.5.5 Wet-location test . 25
5.6 Nipples . 25
6 Cast metal conduit bodies and covers. 25

6.1 General . 25
6.1.1 Applicability . 25
6.1.2 Openings . 25
6.2 Materials . 25
6.2.1 Wall thickness . 25
6.2.2 Coatings on metallic surfaces . 25
6.3 Integral bushings . 25
6.4 Threads . 26
6.5 Threadless connections . 26
6.6 External thread construction . 26
6.7 Wet-location type . 26
7 Conduit bodies and covers . 30
7.1 Cross-sectional area . 30
7.2 Connection to conduit . 30
7.3 Straight conduit bodies . 32
7.4 Angle conduit bodies . 32
7.5 Short conduit bodies . 33
8 Marking . 35
8.1 All fittings . 35
8.1.1 Permanence and legibility . 35
8.1.2 Manufacturer identification . 35
8.1.3 Location of marking . 35
8.1.4 Specific conditions of installation . 35
8.1.5 Specific instructions . 35
8.2 Insulating bushings or parts . 36
8.2.1 Colour coding . 36
8.2.2 Temperature rating . 36
8.2.3 Unthreaded bushings . 36
8.3 Conduit bodies . 36
8.3.1 Manufacturer identification . 36
8.3.2 Specific conditions of installation . 37
8.3.3 Short conduit bodies . 37
8.3.4 Angle conduit bodies . 37
8.3.5 Conduit bodies requiring pulling compound . 37
8.4 Fittings for threaded hubs . 37
8.5 Expansion, expansion-deflection and deflection fittings . 37
9 Type tests . 38
9.1 General . 38
9.1.1 Samples under test . 38
9.1.2 Mechanical connection . 38
9.1.3 Number of samples . 38
9.1.4 Locknuts . 38
9.1.5 Temperature . 38
9.1.6 Assembly . 38
9.2 Concrete-tightness test . 38
9.3 Wet locations test . 39
9.4 Flammability test . 42
9.5 Electrical continuity test .
...