ISO 10924-4:2025
(Main)Road vehicles — Circuit breakers — Part 4: Medium circuit breakers with tabs (Blade type), Form CB15
Road vehicles — Circuit breakers — Part 4: Medium circuit breakers with tabs (Blade type), Form CB15
This document specifies medium circuit breakers with tabs (blade type), Form CB15, for use in road vehicles. It establishes, for this circuit breaker form, the rated current, test procedures, performance requirements and dimensions. This document is intended to be used in conjunction with ISO 10924-1 and ISO 10924-2. The numbering of its clauses corresponds to that of ISO 10924-1, whose requirements are applicable, except where modified by requirements particular to this document. This document is applicable to circuit breakers with a rated voltage of 14 V (DC) or 28 V (DC) or 58 V (DC), a current rating of no greater than 40 A and a breaking capacity of 2 000 A, intended for use in road vehicles with a nominal voltage of 12 V (DC) or 24 V (DC) or 48 V (DC). The circuit breakers are different in dimensions and functions, such as electric reset, automatic reset, manual reset and switchable. NOTE This type of circuit breaker is intended to be used in applications such as medium fuse-links in accordance with ISO 8820-3. While the tab dimensions and current ratings can be the same, there can be differences in performance which the user of these products is advised to consider.
Véhicules routiers — Coupe-circuits — Partie 4: Coupe-circuits moyens à languettes (de type lame), forme CB15
General Information
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Standards Content (Sample)
International
Standard
ISO 10924-4
Third edition
Road vehicles — Circuit breakers —
2025-03
Part 4:
Medium circuit breakers with tabs
(Blade type), Form CB15
Véhicules routiers — Coupe-circuits —
Partie 4: Coupe-circuits moyens à languettes (de type lame),
forme CB15
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Marking, labelling and colour coding . 2
5 Tests and requirements . 2
5.1 General .2
5.1.1 General test conditions .2
5.1.2 -Test sequence plan .3
5.1.3 Test cable sizes .3
5.2 Voltage drop .4
5.2.1 Purpose .4
5.2.2 Tests .4
5.2.3 Requirements .4
5.3 Maximum housing temperature .4
5.4 Environmental conditions .5
5.5 Operating time-rating .5
5.5.1 Purpose .5
5.5.2 Tests .5
5.5.3 Requirements .5
5.6 Current steps .5
5.7 No current trip and reset temperature .5
5.8 Absolute breaking capacity .5
5.8.1 Purpose .5
5.8.2 Tests .6
5.8.3 Requirements .6
5.9 Breaking capacity .6
5.9.1 Purpose .6
5.9.2 Tests .6
5.9.3 Requirements .6
5.10 Strength of terminals.6
5.11 Endurance .6
5.11.1 Purpose .6
5.11.2 Tests .6
5.11.3 Requirements .7
5.12 Dielectric strength .7
5.12.1 Purpose .7
5.12.2 Tests .7
5.12.3 Requirement .7
6 Dimensions and designation example . 8
6.1 Dimensions .8
6.1.1 Category A .8
6.1.2 Category B .9
6.1.3 Category C .9
6.1.4 Category D .10
6.1.5 Category E .10
6.1.6 Categories F and G .11
6.1.7 Category H .11
6.1.8 Category J . 12
6.1.9 Category K . 12
6.2 Designation example . 13
iii
Foreword
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with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
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in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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rights in respect thereof. As of the date of publication of this document, ISO [had/had not] received notice of
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this may not represent the latest information, which may be obtained from the patent database available at
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This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 32,
Electrical and electronic components and general system aspects.
This third edition cancels and replaces the second edition (ISO 10924-4:2015), which has been technically
revised.
The main changes are as follows:
— in Table 2 the test sequence plans were modified for tests No 1, 7, 14, 15 and 19;
— the voltage test at 5.2.2 has been split into fast and standard versions of the circuit breaker;
— the tests for dielectric strength in 5.12.1 and the requirements in 5.12.2 have been clarified.
A list of all parts in the ISO 10924 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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