Electrical accessories - Circuit-breakers for overcurrent protection for household and similar installations - Part 3: Circuit-breakers for DC operation

IEC 60898-3:2019(E) applies to DC circuit-breakers, having a rated DC voltage not exceeding 440 V, a rated current not exceeding 125 A and a rated short-circuit capacity not exceeding 10 000 A.
These circuit-breakers are intended for the protection against overcurrents of wiring installations of buildings and similar applications; they are designed for use by uninstructed people and for not being maintained.

General Information

Status
Published
Publication Date
04-Apr-2019
Current Stage
PPUB - Publication issued
Completion Date
05-Apr-2019
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IEC 60898-3:2019 - Electrical accessories - Circuit-breakers for overcurrent protection for household and similar installations - Part 3: Circuit-breakers for DC operation
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IEC 60898-3
Edition 1.0 2019-04
INTERNATIONAL
STANDARD
Electrical accessories – Circuit-breakers for overcurrent protection for
household and similar installations –
Part 3: Circuit-breakers for DC operation
IEC 60898-3:2019-04(en)
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 60898-3
Edition 1.0 2019-04
INTERNATIONAL
STANDARD
Electrical accessories – Circuit-breakers for overcurrent protection for
household and similar installations –
Part 3: Circuit-breakers for DC operation
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.50 ISBN 978-2-8322-6676-2

Warning! Make sure that you obtained this publication from an authorized distributor.

® Registered trademark of the International Electrotechnical Commission
---------------------- Page: 3 ----------------------
– 2 – IEC 60898-3:2019 © IEC 2019
CONTENTS

FOREWORD ........................................................................................................................... 9

1 Scope ............................................................................................................................ 11

2 Normative references .................................................................................................... 12

3 Terms and definitions .................................................................................................... 12

3.1 Devices ................................................................................................................. 13

3.2 General terms ....................................................................................................... 13

3.3 Constructional elements ........................................................................................ 15

3.4 Conditions of operation ......................................................................................... 18

3.5 Characteristic quantities ....................................................................................... 19

3.6 Definitions related to insulation co-ordination ........................................................ 23

4 Classification ................................................................................................................. 25

4.1 General ................................................................................................................. 25

4.2 According to the number of poles .......................................................................... 25

4.3 According to the current direction through the poles.............................................. 25

4.4 According to the protection against external influences ......................................... 26

4.5 According to the method of mounting .................................................................... 26

4.6 According to the methods of connection ................................................................ 26

4.6.1 According to the fixation system .................................................................... 26

4.6.2 According to the type of terminals .................................................................. 26

4.7 According to the instantaneous tripping current (see 3.5.18) ................................. 26

5 Characteristics of circuit-breakers.................................................................................. 26

5.1 List of characteristics ............................................................................................ 26

5.2 Rated quantities .................................................................................................... 27

5.2.1 Rated voltages .............................................................................................. 27

5.2.2 Rated direct current (I ) ................................................................................ 27

5.2.3 Rated short-circuit capacity (I ) ................................................................... 27

5.2.4 Rated making and breaking capacity of an individual pole (I ) ................... 27

cn1

5.3 Standard and preferred values .............................................................................. 28

5.3.1 Preferred values of rated voltage ................................................................... 28

5.3.2 Preferred values of rated current ................................................................... 28

5.3.3 Values of rated short-circuit capacity ............................................................. 28

5.3.4 Standard ranges of instantaneous tripping ..................................................... 28

5.3.5 Standard value of rated impulse withstand voltage (U ) ............................. 28

imp

6 Marking and other product information ........................................................................... 29

7 Standard conditions for operation in service .................................................................. 30

7.1 General ................................................................................................................. 30

7.2 Ambient air temperature range .............................................................................. 30

7.3 Altitude ................................................................................................................. 31

7.4 Atmospheric conditions ......................................................................................... 31

7.5 Conditions of installation ....................................................................................... 31

7.6 Pollution degree .................................................................................................... 31

8 Requirements for construction and operation ................................................................. 31

8.1 Mechanical design ................................................................................................ 31

8.1.1 General ......................................................................................................... 31

8.1.2 Mechanism .................................................................................................... 31

8.1.3 Clearances and creepage distances (see Annex A) ....................................... 33

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IEC 60898-3:2019 © IEC 2019 – 3 –

8.1.4 Screws, current-carrying parts and connections ............................................. 35

8.1.5 Terminals for external conductors .................................................................. 36

8.1.6 Non-interchangeability ................................................................................... 38

8.1.7 Mechanical mounting of plug-in type circuit-breakers ..................................... 39

8.2 Protection against electric shock ........................................................................... 39

8.3 Dielectric properties and isolating capability .......................................................... 39

8.3.1 General ......................................................................................................... 39

8.3.2 Dielectric properties ....................................................................................... 40

8.3.3 Isolating capability ......................................................................................... 40

8.3.4 Dielectric strength at rated impulse withstand voltage (U ) ........................ 40

imp

8.4 Temperature rise .................................................................................................. 40

8.4.1 Temperature rise limits .................................................................................. 40

8.4.2 Ambient air temperature ................................................................................ 40

8.5 Uninterrupted duty ................................................................................................ 41

8.6 Automatic operation .............................................................................................. 41

8.6.1 Standard time-current zone ........................................................................... 41

8.6.2 Conventional quantities ................................................................................. 42

8.6.3 Tripping characteristic ................................................................................... 42

8.7 Mechanical and electrical endurance .................................................................... 42

8.8 Performance at short-circuit currents and at small DC currents ............................. 43

8.9 Resistance to mechanical shock and impact ......................................................... 43

8.10 Resistance to heat ................................................................................................ 43

8.11 Resistance to abnormal heat and to fire ................................................................ 43

8.12 Resistance to rusting ............................................................................................ 43

8.13 Behaviour in case of making inrush current ........................................................... 43

8.14 Power loss ............................................................................................................ 43

8.15 Requirement of small DC currents......................................................................... 44

9 Tests ............................................................................................................................. 44

9.1 Type tests and test sequences .............................................................................. 44

9.2 Test conditions ..................................................................................................... 45

9.3 Test of indelibility of marking ................................................................................ 46

9.4 Test of reliability of screws, current-carrying parts and connections ...................... 46

9.5 Tests of reliability of screw-type terminals for external copper conductors............. 47

9.6 Test of protection against electric shock ............................................................... 49

9.7 Test of dielectric properties ................................................................................... 49

9.7.1 Resistance to humidity ................................................................................... 49

9.7.2 Insulation resistance of the main circuit ......................................................... 50

9.7.3 Dielectric strength of the main circuit ............................................................. 51

9.7.4 Insulation resistance and dielectric strength of auxiliary circuits..................... 51

9.7.5 Verification of impulse withstand voltages (across clearances and

across solid insulation) and of leakage current across open contacts ............. 52

9.8 Test of temperature rise and measurement of power loss ..................................... 55

9.8.1 Ambient air temperature ................................................................................ 55

9.8.2 Test procedure .............................................................................................. 55

9.8.3 Measurement of the temperature of parts ...................................................... 55

9.8.4 Temperature rise of a part ............................................................................. 55

9.8.5 Measurement of power loss ........................................................................... 55

9.9 28-day test ............................................................................................................ 56

9.10 Test of tripping characteristic ................................................................................ 56

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– 4 – IEC 60898-3:2019 © IEC 2019

9.10.1 General ......................................................................................................... 56

9.10.2 Test of time-current characteristic .................................................................. 56

9.10.3 Test of instantaneous tripping, of correct opening of the contacts and of

the trip-free function ...................................................................................... 56

9.10.4 Test of effect of single-pole loading on the tripping characteristic of

multipole circuit-breakers ............................................................................... 57

9.10.5 Test of effect of ambient temperature on the tripping characteristic ............... 58

9.11 Verification of mechanical and electrical endurance .............................................. 58

9.11.1 General test conditions .................................................................................. 58

9.11.2 Test procedure .............................................................................................. 58

9.11.3 Condition of the circuit-breaker after test ....................................................... 59

9.12 Short-circuit tests .................................................................................................. 59

9.12.1 General ......................................................................................................... 59

9.12.2 Values of test quantities ................................................................................ 60

9.12.3 Tolerances on test quantities ......................................................................... 60

9.12.4 Test circuit for short-circuit performance ........................................................ 60

9.12.5 Time constant of the test circuits ................................................................... 61

9.12.6 Measurement and verification of I t and of the peak current (I ) .................... 62

9.12.7 Calibration of the test circuit .......................................................................... 62

9.12.8 Interpretation of records ................................................................................ 62

9.12.9 Condition of the circuit-breaker for test .......................................................... 62

9.12.10 Behaviour of the circuit-breaker during short-circuit tests ............................... 64

9.12.11 Test procedure .............................................................................................. 64

9.12.12 Verification of the circuit breaker after short circuit tests ................................ 67

9.13 Mechanical stresses ............................................................................................. 68

9.13.1 Mechanical shock .......................................................................................... 68

9.13.2 Resistance to mechanical stresses and impact .............................................. 68

9.14 Test of resistance to heat ...................................................................................... 71

9.15 Resistance to abnormal heat and to fire ................................................................ 72

9.16 Test of resistance to rusting .................................................................................. 73

9.17 Verification of the behaviour in case of making inrush current ............................... 73

9.17.1 General ......................................................................................................... 73

9.17.2 Values of the test quantities........................................................................... 73

9.17.3 Limit deviations of the test quantities ............................................................. 74

9.17.4 Test circuit for the determination of the withstand capacity against

making currents ............................................................................................. 74

9.17.5 Testing for determination of the withstand capacity against making

currents ......................................................................................................... 75

Annex A (normative) Determination of clearances and creepage distances .......................... 87

A.1 General ................................................................................................................. 87

A.2 Orientation and location of a creepage distance .................................................... 87

A.3 Creepage distances where more than one material is used ................................... 87

A.4 Creepage distances split by floating conductive part ............................................. 87

A.5 Measurement of creepage distances and clearances ............................................ 87

Annex B (normative) Test sequences and number of samples necessary to prove

compliance with this document ............................................................................................. 92

B.1 Test sequences .................................................................................................... 92

B.2 Number of samples to be submitted for full test procedure and acceptance

criteria .................................................................................................................. 93

B.3 Number of samples to be submitted for simplified test procedure .......................... 94

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IEC 60898-3:2019 © IEC 2019 – 5 –

Annex C (informative) Co-ordination under short-circuit conditions between a circuit-

breaker and another short-circuit protective device (SCPD) associated in the same

circuit .................................................................................................................................... 97

C.1 General ................................................................................................................. 97

C.2 Purpose ................................................................................................................ 97

C.3 General requirements for the co-ordination of a circuit-breaker with another

SCPD ................................................................................................................... 98

C.3.1 General consideration .................................................................................... 98

C.3.2 Take-over current .......................................................................................... 98

C.3.3 Behaviour of C in association with another SCPD ........................................ 98

C.4 Type and characteristics of the associated SCPD ................................................. 98

C.5 Verification of selectivity ....................................................................................... 99

C.6 Verification of back-up protection .......................................................................... 99

C.6.1 Determination of the take-over current ........................................................... 99

C.6.2 Verification of back-up protection ................................................................... 99

C.6.3 Tests for verification of back-up protection .................................................. 100

C.6.4 Results to be obtained ................................................................................. 101

Annex D (informative) Examples of terminals ..................................................................... 105

Annex E (informative) Correspondence between IEC and AWG copper conductors ............ 108

Annex F (normative) Arrangement for short-circuit test ...................................................... 109

Annex G (normative) Routine tests .................................................................................... 112

G.1 General ............................................................................................................... 112

G.2 Tripping tests ...................................................................................................... 112

G.3 Verification of clearances between open contacts ............................................... 112

Annex H (normative) Particular requirements for circuit-breakers with screwless type

terminals for external copper conductors............................................................................. 113

H.1 Scope ................................................................................................................. 113

H.2 Normative references .......................................................................................... 113

H.3 Terms and definitions .......................................................................................... 113

H.4 Classification ...................................................................................................... 114

H.5 Characteristics of circuit-breakers ....................................................................... 114

H.6 Marking and other product information ................................................................ 114

H.7 Standard conditions for operation in service ........................................................ 114

H.8 Requirements for construction and operation ...................................................... 115

H.8.1 Connection or disconnection of conductors .................................................. 115

H.8.2 Dimensions of connectable conductors ........................................................ 115

H.8.3 Connectable cross-sectional areas .............................................................. 116

H.8.4 Insertion and disconnection of conductors ................................................... 116

H.8.5 Design and construction of terminals ........................................................... 116

H.8.6 Resistance to ageing ................................................................................... 116

H.9 Tests .................................................................................................................. 116

H.9.1 Test of reliability of screwless terminals ....................................................... 116

H.9.2 Tests of reliability of terminals for external conductors: mechanical

strength ....................................................................................................... 117

H.9.3 Cycling test.................................................................................................. 118

H.10 Reference documents ......................................................................................... 120

Annex I (normative) Particular requirements for circuit-breakers with flat quick-

connect terminations ........................................................................................................... 121

I.1 Scope ................................................................................................................. 121

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– 6 – IEC 60898-3:2019 © IEC 2019

I.2 Normative references .......................................................................................... 121

I.3 Terms and definitions .......................................................................................... 121

I.4 Classification ...................................................................................................... 122

I.5 Characteristics of circuit-breakers ....................................................................... 122

I.6 Marking and other product information ................................................................ 122

I.7 Standard conditions for operation in service ........................................................ 122

I.8 Requirements for construction and operation ...................................................... 122

I.8.1 Clearances and creepage distances (see Annex A) ..................................... 122

I.8.2 Terminals for external conductors ................................................................ 123

I.9 Tests .................................................................................................................. 123

I.9.1 Mechanical overload-force ........................................................................... 123

Annex J (normative) Specific requirements for circuit-breakers with screw-type

terminals for external untreated aluminium conductors and with aluminium screw-type

terminals for use with copper or with aluminium conductors ................................................ 128

J.1 Scope ................................................................................................................. 128

J.2 Normative references .......................................................................................... 128

J.3 Terms and definitions .......................................................................................... 128

J.4 Classification ...................................................................................................... 129

J.5 Characteristics of circuit-breakers ....................................................................... 129

J.6 Marking and other product information ................................................................ 129

J.7 Standard conditions for operation in service ........................................................ 129

J.8 Constructional requirements ............................................................................... 130

J.9 Tests .................................................................................................................. 130

J.9.1 Test conditions ............................................................................................ 132

J.9.2 Current cycling test ...................................................................................... 132

J.10 Reference documents ......................................................................................... 137

Bibliography ........................................................................................................................ 138

Figure 1 – Thread forming tapping screw .............................................................................. 75

Figure 2 – Thread cutting tapping screw ............................................................................... 75

Figure 3 – Single-pole circuit-breaker or pole of multiple circuit breaker ................................ 75

Figure 4 – Two-pole circuit-breaker with two protected poles ................................................ 76

Figure 5 – Three-pole circuit-breaker with two protected poles and non-polarized

protected M pole ................................................................................................................... 76

Figure 6 – Calibration of the test circuit in case of direct currents ......................................... 77

Figure 7 –Mechanical shock test apparatus (see 9.13.1) .....................
...

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