ISO 6722:2006

INTERNATIONAL ISO
STANDARD 6722
Second edition
2006-08-01

Road vehicles — 60 V and 600 V
single-core cables — Dimensions, test
methods and requirements
Véhicules routiers — Câbles monoconducteurs de 60 V et 600 V —
Dimensions, méthodes d'essai et exigences



Reference number
ISO 6722:2006(E)
©
ISO 2006

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ISO 6722:2006(E)
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ISO 6722:2006(E)
Contents Page
Foreword. v
1 Scope. 1
2 Normative references. 1
3 Terms and definitions. 2
4 General. 2
4.1 Caution. 2
4.2 Conductors. 2
4.3 Tests. 3
4.4 General test conditions. 3
4.5 Ovens. 3
4.6 Representative conductor sizes for testing. 3
4.7 Recommended colours . 3
5 Dimensions. 5
5.1 Outside cable diameter . 5
5.2 Insulation thickness . 5
5.3 Conductor diameter. 6
6 Electrical characteristics. 7
6.1 Conductor resistance. 7
6.2 Withstand voltage. 8
6.3 Insulation faults . 10
6.4 Insulation volume resistivity . 11
7 Mechanical characteristics. 11
7.1 Pressure test at high temperature . 11
7.2 Strip force. 13
8 Low-temperature characteristics. 14
8.1 Winding. 14
8.2 Impact. 16
9 Resistance to abrasion. 18
9.1 Usage of test . 18
9.2 Sandpaper abrasion . 18
9.3 Scrape abrasion. 20
10 Heat ageing. 22
10.1 Long-term ageing, 3 000 h . 22
10.2 Short-term ageing, 240 h. 23
10.3 Thermal overload. 23
10.4 Shrinkage by heat. 24
11 Resistance to chemicals . 25
11.1 Compliance. 25
11.2 Fluid compatibility . 25
11.3 Durability of cable marking. 27
11.4 Resistance to ozone . 27
11.5 Resistance to hot water. 28
11.6 Temperature and humidity cycling . 29
12 Resistance to flame propagation . 31
12.1 Test sample. 31
12.2 Apparatus. 31
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ISO 6722:2006(E)
12.3 Procedure. 31
12.4 Requirement. 31
Annex A (informative) Conductors . 32
Annex B (informative) Recommended colours. 33
Annex C (informative) High-volume cable constructions . 34
Annex D (informative) Sources for reference materials . 36
Bibliography . 37

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ISO 6722:2006(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 6722 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 3, Electrical
and electronic equipment.
This second edition cancels and replaces the first edition (ISO 6722:2002) which has been technically revised.

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INTERNATIONAL STANDARD ISO 6722:2006(E)

Road vehicles — 60 V and 600 V single-core cables —
Dimensions, test methods and requirements
1 Scope
This International Standard specifies the dimensions, test methods, and requirements for single-core 60 V
cables intended for use in road vehicle applications where the nominal system voltage is u (60 V d.c. or
25 V a.c.). It also specifies additional test methods and/or requirements for 600 V cables intended for use in
road vehicle applications where the nominal system voltage is > (60 V d.c. or 25 V a.c.) to u (600 V d.c. or
600 V a.c.). It also applies to individual cores in multi-core cables.
Eight temperature classes are defined in Table 1.
Table 1 — Temperature class rating
Class Temperature
A − 40 °C to  85 °C
B – 40 °C to 100 °C
C − 40 °C to 125 °C
D − 40 °C to 150 °C
E − 40 °C to 175 °C
F − 40 °C to 200 °C
G − 40 °C to 225 °C
H − 40 °C to 250 °C
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 1817, Rubber, vulcanized — Determination of the effect of liquids
ISO 6931-1, Stainless steels for springs — Part 1: Wire
IEC 60757, Code for designation of colours
IEC 60811-2-1, Common test methods for insulating and sheathing materials of electrical and optical
cables — Part 2-1: Methods specific to elastomeric compounds — Ozone resistance, hot set and mineral oil
immersion tests
ASTM B1, Standard Specification for Hard-Drawn Copper Wire
ASTM B3, Standard Specification for Soft or Annealed Copper Wire
ASTM B33, Standard Specification for Tinned Soft or Annealed Copper Wire for Electrical Purposes
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ISO 6722:2006(E)
ASTM B298, Standard Specification for Silver-Coated Soft or Annealed Copper Wire
ASTM B355, Standard Specification for Nickel-Coated Soft or Annealed Copper Wire
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
60 Volt (V) cable
cable intended for use in road vehicle applications where the nominal system voltage is equal to or less than
60 V d.c. or 25 V a.c.
3.2
600 Volt (V) cable
cable intended for use in road vehicle applications where the nominal system voltage is greater than
(60 V d.c. or 25 V a.c.) and less than (600 V d.c. or 600 V a.c.)
NOTE a.c. tests are performed at 50 Hz or 60 Hz. Applications at higher frequencies may require additional testing.
3.3
cable family
group with multiple conductor sizes having the same conductor strand coating, insulation formulation and
wall-thickness type
3.4
nominal (value)
suitable approximate value used to designate or identify a component
4 General
4.1 Caution
Special care shall be taken with cables used with voltages above (60 V d.c. or 25 V a.c.) to protect them from
mechanical stress in order to avoid shock hazard. Regardless of wall thickness, 600 V cables shall meet the
“resistance to abrasion” requirements for thick wall cable.
4.2 Conductors
The conductors shall consist of plain or coated copper strands as shown in Table 2. Conductor sizes
2
W 0,5 mm shall consist of soft annealed copper or annealed compressed/compacted wires. Conductor sizes
2
< 0,5 mm shall consist of soft annealed copper, soft annealed compressed/compacted copper, hard
unannealed copper or a copper alloy. The specifications for the conductors shall be completed by material
specifications. Elongation requirements shall be established by agreement between customer and supplier.
The finished cable shall meet the resistance requirements of 6.1 for all conductors except alloys. When an
alloy is used, the resistance requirement shall be established by agreement between customer and supplier.
NOTE Examples of strandings are shown in Table A.1. These strandings highlight examples of conceptual
configurations and are not intended to reflect any preferred constructions. Other strandings' configurations may be used
provided they meet the requirements shown above and are agreed upon between customer and supplier.
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ISO 6722:2006(E)
Table 2 — Conductor specifications
ASTM B1 Hard-drawn copper wire
ASTM B3 Soft or annealed copper wire
ASTM B33 Tinned soft or annealed copper wire
ASTM B298 Silver-coated soft or annealed copper wire
ASTM B355 Nickel-coated soft or annealed copper wire
NOTE Silver- and nickel-coated conductors are intended for use
with high “temperature class ratings”.
4.3 Tests
The cables shall be submitted to the tests as specified in Table 3.
4.4 General test conditions
Test samples for all tests except those in Clause 5 and in 6.1 and 6.3 shall be preconditioned for at least 16 h
at a room temperature of (23 ± 5) °C. Unless otherwise specified, all tests other than “in-process” tests shall
be conducted at this same temperature. Where no tolerance is specified, all values shall be considered to be
approximate.
4.5 Ovens
Unless otherwise specified, when an oven is required, it shall be a hot air oven. The air contained in the oven
shall be completely changed at least eight (8) times but not more than twenty (20) times per hour at the
specified temperature.
4.6 Representative conductor sizes for testing
When a test is required, all combinations of conductor size, wall thickness and insulation formulation shall
meet the appropriate requirements. However, if representative conductor sizes for testing are permitted,
compliance for a cable family may be demonstrated by testing examples of large and small conductor sizes
only. Permission to show compliance for a cable family by testing “representative conductor sizes” shall be
established by agreement between customer and supplier.
4.7 Recommended colours
A list of recommended colours is shown in Table B.1
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ISO 6722:2006(E)
Table 3 — Tests

c
In-process Certification If required
Clause Test description

a b b
Initial Initial
tests Periodic Periodic
5 Dimensions
5.1 Outside cable diameter — × × — —
5.2 Insulation thickness — × × — —
5.3 Conductor diameter — — — × ×
6 Electrical characteristics
6.1 Conductor resistance — × × — —
d d
6.2 Withstand voltage — — —
d
6.3 Insulation faults — — — —
6.4 Insulation volume resistivity — — — × ×
7 Mechanical characteristics
7.1 Pressure test at high temperature — × × — —
7.2 Strip force — — — × ×
8 Low-temperature characteristics
8.1 Winding — × × — —
8.2 Impact — — — × ×
e e
9 Resistance to abrasion
— — —
9.2 Sandpaper abrasion — — — — —
9.3 Scrape abrasion — — — — —
10 Heat ageing
10.1 Long-term ageing, 3 000 h — × — — —
10.2 Short-term ageing, 240 h — × × — —
10.3 Thermal overload — — — × ×
10.4 Shrinkage by heat — — —
× ×
11 Resistance to chemicals
f, g f, g
11.2 Fluid compatibility — — —
g g
11.3 Durability of cable marking — — —
g
11.4 Resistance to ozone — — — —
g
11.5 Resistance to hot water — — — —
g
11.6 Temperature and humidity cycling — — — —
12 Resistance to flame propagation — × × — —
"X" To be applied.
"—" Not applicable.
a
A test made on all cables during or after manufacture.
b
The frequency of periodic testing shall be established by agreement between customer and supplier.
c
The usage of "if required” tests shall be established by agreement between customer and supplier.
d
Some cables are rated at 60 V and others at 600 V. See 6.2 and 6.3 for details.
e
See Clause 9.
f
Some fluids are for “certification” and others are “if required”. See 11.2 for details.
g
Compliance for a cable family may be demonstrated by testing examples of large and small conductor sizes only. See 4.6 for
details.

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ISO 6722:2006(E)
5 Dimensions
5.1 Outside cable diameter
5.1.1 Test Sample
Prepare a test sample 3 m in length.
5.1.2 Apparatus
Use a measuring device with an accuracy of ± 0,01 mm. The device shall not cause deformation.
5.1.3 Procedure
Take three sets of measurements at positions separated by 1 m and record the highest and lowest outside
cable diameter at each position.
5.1.4 Requirement
All measurements shall be within the limits of the appropriate maximum and minimum “outside cable
diameter” specified in Table 4 and Table C.1. The values in Table 4 are normative. Since the values in
Table C.1 are informative, they are not required; however, they may be applied by agreement between
customer and supplier.
5.2 Insulation thickness
5.2.1 Test samples
Prepare three test samples from a cable sample 3 m in length. Take the test samples at 1 m intervals. Strip
the insulation from the cable. A test sample consists of a thin cross section of insulation. Take care not to
deform the test sample during the preparation process. If cable marking causes indentation of the insulation,
take the first test sample through this indentation.
5.2.2 Apparatus
Use a measuring device with an accuracy of ± 0,01 mm. The device shall not cause deformation.
5.2.3 Procedure
Place the test sample under the measuring equipment with the plane of the cut perpendicular to the optical
axis. Determine the minimum “insulation thickness”.
5.2.4 Requirement
No single value shall be less than the appropriate minimum insulation thickness specified in Table 4.
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ISO 6722:2006(E)
Table 4 — Dimensions
ISO conductor Thick wall Thin wall Ultra-thin wall
Outside Outside Outside
Insulation Insulation Insulation
Size Diameter cable cable cable
thickness thickness thickness
diameter diameter diameter
2
mm mm mm mm mm mm mm mm
max. nominal min. max. nominal min. max. nominal min. max.
0,13 0,55 — — — 0,25 0,20 1,05 0,20 0,16 0,95
0,22 0,70 — — — 0,25 0,20 1,20 0,20 0,16 1,05
a
0,35 0,90 — — — 0,25 0,20 0,20 0,16 1,20
1,40
0,50 1,10 0,60 0,48 2,30 0,28 0,22 1,60 0,20 0,16 1,40
0,75 1,30 0,60 0,48 2,50 0,30 0,24 1,90 0,20 0,16 1,60
1 1,50 0,60 0,48 2,70 0,30 0,24 2,10 0,20 0,16 1,75
1,5 1,80 0,60 0,48 3,00 0,30 0,24 2,40 0,20 0,16 2,10
2 2,00 0,60 0,48 3,30 0,35 0,28 2,80 0,25 0,20 2,40
2,5 2,20 0,70 0,56 3,60 0,35 0,28 3,00 0,25 0,20 2,70
3 2,40 0,70 0,56 4,10 0,40 0,32 3,40 — — —
4 2,80 0,80 0,64 4,40 0,40 0,32 3,70 — — —
5 3,10 0,80 0,64 4,90 0,40 0,32 4,20 — — —
6 3,40 0,80 0,64 5,00 0,40 0,32 4,30 — — —
10 4,50 1,00 0,80 6,50 0,60 0,48 6,00 — — —
16 6,30 1,00 0,80 8,30 0,65 0,52 7,90 — — —
25 7,80 1,30 1,04 10,40 0,65 0,52 9,40 — — —
35 9,00 1,30 1,04 11,60 — — — — — —
50 10,50 1,50 1,20 13,50 — — — — — —
70 12,50 1,50 1,20 15,50 — — — — — —
95 14,80 1,60 1,28 18,00 — — — — — —
120 16,50 1,60 1,28 19,70 — — — — — —
NOTE Outside cable diameter minimum values for high-volume cable constructions are shown in Table C.1. Since the values in
Table C.1 are informative, they are not required; however, they may be applied by agreement between customer and supplier.
a 2
The outside cable diameter for conductor size 0,35 mm with 7 strands shall be a maximum of 1,30 mm.
5.3 Conductor diameter
5.3.1 Test samples
The usage of this test shall be established by agreement between customer and supplier. In case of disputed
results, a refereeing method is provided.
Referee test samples: in case of a dispute, prepare three test samples from a cable sample 3 m in length.
Take the test samples at 1 m intervals. A test sample consists of a 20 mm length of cable. Take care not to
deform the test sample. Immerse the test samples in a casting resin. After hardening, take a section
perpendicular to the axis of the test sample.
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ISO 6722:2006(E)
5.3.2 Apparatus
Carry out this test on the same apparatus used for the measurement of the insulation thickness (see 5.2).
Referee apparatus: in case of a dispute, the measuring device shall be capable of at least 10 × linear
magnification.
5.3.3 Procedure
Check the conductor diameter by measuring the inside diameter of the samples used in 5.2 and recording the
maximum inside diameter for each test sample.
Referee procedure: in case of a dispute, measure the conductor diameter using the “referee test samples”
and the “referee apparatus”. Record the maximum conductor diameter for each test sample.
5.3.4 Requirement
The measured value shall not exceed the maximum value, specified in Table 4. This measured value is also
required in 6.4.
6 Electrical characteristics
6.1 Conductor resistance
6.1.1 Test samples
Prepare a test sample 1 m in length plus the length necessary for connections. Other lengths may be used
providing that the resistance reading is adjusted using the method shown in 6.1.3. The ends of the test sample
may be soldered.
6.1.2 Apparatus
Use a resistance-measuring device with an accuracy of ± 0,5 % of the measured value and a thermometer
with an accuracy of ± 0,5 °C.
6.1.3 Procedure
Measure the temperature of the test sample and the unsoldered length. Take care to ensure that connections
are secure. Measure the resistance of the test sample. Correct the measured value using the following
equation:
R
t
R =
20
⎡⎤
Lt1+−0,003 93 20
()
⎣⎦
where
R is the corrected conductor resistance at the reference temperature of 20 °C, expressed in milliohms
20
per metre;
R is the conductor resistance measured at the conductor temperature, expressed in milliohms;
t
L is the unsoldered conductor length, expressed in metres;
t is the conductor temperature at the time of measuring, expressed in degrees centigrade.
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ISO 6722:2006(E)
NOTE The value of 0,003 93 is the temperature coefficient for copper with 100 % conductivity at a temperature of
20 °C. For coated wires or alloys, the correction factor shall be established by agreement between customer and supplier.
6.1.4 Requirement
The corrected value shall not exceed the appropriate maximum resistance specified in Table 5.
Conductors produced from silver-coated strands shall not exceed the maximum conductor resistance per
length for plain copper.
6.2 Withstand voltage
6.2.1 Test sample
Prepare a test sample of a minimum length of 350 mm, strip 25 mm of insulation from each end and twist the
ends together to form a loop.
6.2.2 Apparatus
Partially fill an electrically non-conductive vessel with salt water (aqueous solution of 3 % by mass of NaCl)
with the ends of the test sample emerging above the bath as shown in Figure 1. Use a 50 Hz or 60 Hz a.c.
voltage source.
6.2.3 Procedure
6.2.3.1 60 V cable
Immerse the test sample in the bath, as shown in Figure 1, for 4 h and then apply a test voltage of 1 kV
(r.m.s.) for 30 min between the conductor and the bath. Then increase the voltage at a rate of 500 V/s until the
following value is reached:
2
⎯ 3 kV (r.m.s.) for cables < 0,5 mm ;
2
⎯ 5 kV (r.m.s.) for cables W 0,5 mm .
6.2.3.2 600 V cable
After completing the procedure for a 60 V cable, hold the 3 kV or 5 kV for a further 5 min.
6.2.4 Requirement
Breakdown shall not occur.
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ISO 6722:2006(E)
Table 5 — Conductor resistance
Maximum conductor resistance per length
ISO conductor
mΩ/m at 20 °C
Size Plain copper Sn-plated copper Ni-plated copper
2
mm
0,13 136 140 142
0,22 84,8 86,5 87,9
0,35 54,4 55,5 56,8
0,50 37,1 38,2 38,6
0,75 24,7 25,4 25,7
1 18,5 19,1 19,3
1,5 12,7 13,0 13,2
2 9,42 9,69 9,82
2,5 7,60 7,82 7,92
3 6,15 6,36 6,41
4 4,71 4,85 4,91
5 3,94 4,02 4,11
6 3,14 3,23 3,27
10 1,82 1,85 1,90
16 1,16 1,18 1,21
25 0,743 0,757 0,774
35 0,527 0,538 0,549
50 0,368 0,375 0,383
70 0,259 0,264 0,270
95 0,196 0,200 0,204
120 0,153 0,156 0,159
NOTE Conductor resistance, minimum values for high-volume cable constructions are shown in Table C.2.
Since the values in Table C.2 are informative, they are not required; however, they may be applied by agreement
between customer and supplier.
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ISO 6722:2006(E)

Key
1 test voltage (terminals)
2 non-conductive vessel
3 electrode
4 test sample
5 salt-water bath
Figure 1 — Apparatus for withstand voltage test
6.3 Insulation faults
6.3.1 Test sample
All cable-produced.
6.3.2 Apparatus
Use a sinusoidal voltage source set at the value shown in Table 6. The test electrode may consist of metal
ball chains, metal brushes or any other type of suitable electrodes. Choose the electrode length and frequency
considering the speed of the cable running through the field of the electrode so that each point of the cable is
loaded by at least nine voltage cycles.
Table 6 — Insulation faults
Voltage rating
ISO
conductor size
kV (r.m.s.)
2
60 V cables 600 V cables
mm
3 6
< 0,5
W 0,5 5 8
6.3.3 Procedure
This test shall be carried out under production conditions. Subject all cables to this test. Other methods of test
may be used provided that insulation faults are detected with the same certainty.
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ISO 6722:2006(E)
6.3.4 Requirement
No breakdown shall occur when the earthed cable is drawn through the test electrode.
6.4 Insulation volume resistivity
6.4.1 Usage of test
The usage of this test shall be agreed between customer and supplier.
6.4.2 Test sample
Prepare a test sample of 5 m length and remove 25 mm of insulation from each end.
6.4.3 Apparatus
Partially fill an electrically non-
...