PHILIPPINE NATIONAL STANDARD
DPNS 35-2: 2005
Electric wires and cables – Thermoplastic Insulated Copper Wires and Cables Rated
600 Volts – Part 2 Non Metallic Flat Jacketed Electric Wires – Specification
1.
Scope
This standard specifies requirements for thermoplastic insulated non- metallic flat- jacketed
electric wires with 2 or 3 conductors sizes 2.0 mm² to 5.5 mm² solid or stranded rated 60 ºC,
600 V.
2.
References
The titles of the standard publications referred to in this standard are listed on the inside back
cover.
3.
Definitions
For the purpose of this standard, the following definitions shall apply:
3.1
Type NM (Non-metallic) – thermoplastic jacketed wire containing 2 or 3 PVC
insulated circuit conductors with or without grounding used in wiring system operating at a
voltage not exceeding 600 V and at a temperature not exceeding 60 ºC to be used in dry and
wet locations.
3.2
Filler –material used to fill the gaps between insulated conductors
3.3
Jacket – a protective outer covering over the insulation.
4.
General Requirements
4.1
Materials
4.1.1 Conductor - The conductor shall be annealed copper wire conforming to the
requirements of PNS 260 and PNS 1207.
4.1.2 Jacket and Insulation – The jacket and insulation shall be PVC conforming to the
requirements of PNS 661.
4.1.3 Filler – The filler shall be of non-metallic material
4.2
Insulation and Jacket Thickness
4.2.1 The average thickness of insulation shall not be less than the values indicated in Table
1 and the minimum thickness at any point shall not be less 85% of the values in this table.
DPNS 35-2: 2005
4.2.2 The average thickness of jacket shall not be less than 95% of the values indicated in
Table 1 and the minimum thickness at any point shall not be less than 80% of the values in
this table.
4.3
Minimum acceptable separation of circuit conductor
The minimum acceptable separation of circuit conductor shall conform to Table 2.
4.4
Identification of cores
The identification shall be made by the color of the insulation and shall conform to Table 3.
4.5
Performance and other requirements
4.5.1 Appearance – The finished wire shall be free from imperfections that are not
consistent with the best commercial practice.
4.5.2 Physical Properties of Insulation and Jacket – The insulation of finished wire shall
conform to table 4 when tested by the method specified in Clause 5.
5
5.1
Test Methods
Insulation Thickness
Refer to clause 5.1 of PNS 35 Part 1
5.2
Jacket Thickness
5.2.1 The jacket thickness shall be measured with pin/thickness gauge or other appropriate
measuring device. Caution shall be made so as not to exert much pressure to the sample
during measurement.
5.2.2 The average jacket thickness shall be taken by measuring the cross-section at three or
more points perpendicular to the cable axis and take the mean value. For the minimum
thickness, the thinnest portion may be selected visually or by other means, and the thickness
at this part shall be measured with a pin gauge or a profile projector.
5.3
Separation or Distance Between Circuit Conductors
For solid conductors, the distance between adjoining surfaces of metal conductors shall be
measured with an external caliper or other appropriate measuring device. For stranded
conductors, the distance between the centers of the stranded conductors shall be measured.
5.4
Dielectric withstand Voltage
5.4.1 Spark test – Each single conductor of type NM cables shall individually comply with
spark test requirements of PNS 35 Part 1, prior to assembly and jacketing.
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DPNS 35-2: 2005
Table 1 – Insulation and jacket characteristics of type NM, 60OC, 600 V
Nominal
Sectional
Area,
mm2
2.0
3.5
5.5
Conductor
Composition
Nominal Insulation Nominal
Jacket
No. of Diameter Outside Thickness,
mm
Thickness,
wires
of wires, Diameter,
mm
mm
mm
1
1.60
1.60
0.80
0.80
Approximate Overall
Dimension, mm
Major
Minor
2C
3C
Test Voltage,
kV a.c.
9.58
14.36
4.80
5
Minimum
Insulation
Resistance,
M-km
20OC
50
7
0.60
1.80
0.80
0.80
9.98
14.96
5.00
5
50
1
2.00
2.00
0.80
0.80
10.38
15.56
5.20
5
50
7
0.80
2.40
0.80
0.80
11.18
16.76
5.60
5
50
1
2.60
2.60
0.8
0.80
11.58
17.36
5.80
5
50
7
1.00
3.00
0.8
0.80
12.38
18.56
6.20
5
50
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DPNS 35-2: 2005
Table 2 – Minimum Acceptable Separation of Circuit Conductors In
Flat Multiple Conductor Wire
Sizes of Wire, mm²
Measured between adjoining
surfaces of solid conductors,
mm²
3.18
3.18
3.18
2.0
3.5
5.5
Measured between centers of
stranded conductors, mm²
4.98
5.58
6.18
Table 3- Color Coding of Insulation
Number of Cores
2
3
Color
Black & white
Black, White & Red or
Black, White & Green
Table 4 – Physical Properties of type NM Wire
Test Items
Conductor Resistance
Requirements
Shall comply to the requirements of PNS 260 and
PNS 1207
To withstand the test voltage specified in Table 1
Dielectric Withstand Voltage
Conductor Continuity Test
Insulation
At Room
Resistance
Temperature (20OC)
u
n
a
g
e
d
Tensile Strength
Not less than 10.3 MPa (1.05 kgf/mm²)
Insulation
Elongation
Tensile Strength
Not less than 100 percent
Not less than 10.3 MPa (1.05) kgf/mm²)
Jacket
Elongation
Tensile Strength
a
g
e
d
Shall be continuous on its entire length
Not less than the value specified in Table 1
Insulation
Elongation
Jacket
Tensile Strength
Elongation
Flame Retardant Test
Heat Shock
Heat Deformation
Not less than 100 percent
Not less than 65 percent of the value of
unaged specimen
Die cut specimen – not less than 45 percent of
the value of unaged specimen
Tubular specimen – not less than 65 percent of
the value of unaged specimen
Not less than 70 percent of the value of
unaged specimen
Die cut specimen – not less than 45 percent of
the value of unaged specimen
Flame to extinguish naturally within 60 seconds
No cracks and flaws to develop on the surface or
internally
Thickness reduction shall not exceed 50 percent
of the original thickness
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DPNS 35-2: 2005
5.4.2 After immersion in water at room temperature for 24 h and while still immersed,
specimens of finished cable wound around mandrel shall withstand for 60 s a 48-62 Hz
essentially sinusoidal potential of 5000V. The potential shall be applied from each conductor
separately, to the other conductor or conductors, any grounding conductor, and to the earthgrounded water and mandrel.
5.4.2.1 The apparatus is to consist of an immersion tank; a set of metal mandrels, each a
right-circular cylinder having a diameter equal to seven times the diameter or length of minor
axis of the cable with which it is used; and a testing transformer, circuit breaker, and
voltmeter.
5.4.2.2 The test potential is to be supplied by a 48 – 62 Hz isolation transformer whose rms
output potential is continuously variable from near zero to at least 5000 V at a rate that is not
greater than 500 V/s. With a specimen in the circuit, the output potential is to have a crest
factor (peak voltage divided by rms voltage) equal to 95 – 105 percent of the crest factor of a
pure sine wave over the upper half of the output range. The output voltage is to be monitored
continuously by a voltmeter that (1), if of the analog rather than digital type, shall have a
response time that does not introduce a lagging error greater than 1 percent of full scale at the
specified rate of increase in voltage, and that (2) has an over all accuracy that does not
introduce an error exceeding 5 percent. The maximum current output of which the supply is
capable is to enable routine testing of full reels of the cable without tripping of the output
circuit breaker by charging current.
5.4.2.3 A specimen of finished cable of a length for making seven or more turns around the
applicable diameter of mandrel plus 28 in or 711 mm is to be opened at each end so that the
insulated circuit conductors extend 4 in or 102 mm from the rest of the cable. The insulation
is nor to be damaged. At one end of the specimen, each of the circuit conductors and any
grounding conductor are to be bared for 1 in or 25 mm to facilitate connection to the testing
circuit. The specimen of cable is then to be wound onto the mandrel starting at the center of
the specimen and winding simultaneously toward each end. The ends are then to be secured
so that no less than a 10 in or 254 mm length of cable extends away from the mandrel at each
end of the coil. The specimen and the mandrel on which it is wound are then to be immersed
in tap water at a room temperature for 24 h. During the immersion, the ends of the coil are to
extend at least 8 in or 200 mm above the surface of the water, and the ends are not to become
wet. After the coil has been immersed for 24 h, and while it is still immersed, the potential is
to be increased from near zero at an essentially uniform rate in the range of 10 – 60 V/s. The
increase is to continue in this manner until the voltage is 5000. If the 5000 V level is reached
without breakdown, the voltage is to be held constant at that level for 60 seconds and is then
to be reduced to near zero at an essentially uniform rate in the range of 10 – 60 V/s. The cable
is not acceptable if, during any application of voltage, breakdown occurs in less than 60 s at
5000 V or while the voltage is being increased or decreased.
5.4.3 Each circuit conductor and any grounding conductor shall be continuous throughout the
entire length of finished cable. Finished cable shall be tested for continuity for all sizes
conductor by the cable manufacturer at the cable factory.
5.5
Insulation Resistance
Refer to clause 5.3 of PNS 35- Part 1
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DPNS 35-2: 2005
5.6
Accelerated Aging Test
Refer to clause 5.4 of PNS 35- Part 1
5.7
Tensile strength and elongation of insulation and jacket
5.7.1 Preparation of test specimen – a minimum of three samples approximately 100 mm
long that have been removed from the conductors shall be used. Samples that cannot be
obtained from the finished product, or if the samples obtained is inappropriate, they shall be
obtained from a sheet rolled out from a compound of the same lot, 1 to 3 mm thick, and left
exposed at a temperature of 23ºC ± 2ºC for more than five hours. The specimen shall be
tubular or dumbbell shape whose measurements shall be as close as possible to that shown in
Figure 1 and shall have marks places upon it 20 mm apart. Dumbbell specimen shall be
buffed, laid flat and cut with an acceptable die and be free of surface incisions and
imperfections.
5.7.2
Calculation of the cross-sectional area
5.7.2.1 For tubular specimen – the outer diameter of the insulation is measured at 3 or more
points, and the sectional are calculated from the following formula using the average
measured value.
A=  / 4 (D² - d²)
Where: A= is the cross-sectional area in mm²
D= is the outside diameter of the insulation in mm
d= is the outside diameter of the conductor in mm
5.7.2.2 For dumbbell specimen
A = WT
Where:
A= is the cross-sectional are in mm²
W= is the width in mm
T= is the thickness in mm
100
100
15
25
20
R25
21
40
5
19
20
25
R11
40
5
10
RAC
Unit: mm
Figure 1 - Die-cut specimen
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DPNS 35-2: 2005
5.7.3 Test Procedure – a sample shall be arranged properly to ensure absence of deflection
during the test, and stretch at a speed approximately 500 mm/min. The load and the distance
between the marks corresponding to the cutting points shall be measured. If the sample
breaks outside the marked points, the sample shall be repeated on another sample.
5.7.4 Method of calculating tensile strength and elongation – The tensile strength and
elongation shall be calculated using the formulas below. The values shall be represented by
an average of the obtained from the three specimens.
a.) Tensile strength = Measured load at rupture, Newton
Cross –sectional area of sample,mm²
b.) Elongation
5.8
= final distance – initial distance x 100%
initial distance
Flame Retardant Test
Refer to clause 5.7 of PNS 35 Part 1.
5.9
Heat Shock
Refer to clause 5.7 of PNS 35 Part 1.
5.10
Heat Deformation
Refer to clause 5.8 of PNS 35 Part 1.
6
Sampling
Samples shall be obtained at random from packaged lots and shall have a minimum length of
75m per size.
7
Marking
7.1
A non–metallic sheathed wire shall have a permanent distinctive marking throughout
its entire length. The marking shall be by printing which is to be repeated with an interval of
500 mm or shorter. The marking on the surface shall indicate plainly the following:
7.1.1 The type NM wire
7.1.2 The diameter of wire in mm for solid or the cross sectional area in mm² for stranded.
7.1.3 The number of conductors
7.1.4 The rated voltage and temperature of wire.
7.1.5 The manufacturer’s trade name or brand name
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DPNS 35-2: 2005
7.2
Tag, Reel or Carton Markings – Every shipping length of finished wire shall be
provided with a tag. It may be tied to a coil or glued to the carton ,or the tag may be
eliminated if information is printed in the carton or in the packaging reel . The following
information shall be indicated plainly:
7.2.1
The type NM wire
7.2.2
The diameter of wire in mm for the cross- sectional area in mm² for stranded.
7.2.3
The number of conductors
7.2.4
The rated voltage and temperature of wire
7.2.5
The manufacturer‘s trade name or brand name
7.2.6
The date of manufacture by month and year
7.2.7
The length in meter
7.2.8
The country of origin
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References
The following standards contain provisions that through reference in this text from part of
this national standard. At the time of publication of this PNS, the editions indicated were
valid:
PNS 35-1:2004 Electric wires and cables - Thermoplastic insulated copper wires and cables
rated 600 volts – Part 1: General specification
PNS 260:1990 Annealed Copper Wires - Specifications
PNS 1207: 1997 Soft drawn (annealed) copper stranded conductors for electrical purposes Specifications
UL 719 (July 31,1998) Underwriters Laboratories Inc. Standard for Safety Nonmetallic –
Sheathed Cables
PNS 661:1992 Plasticized polyvinyl chloride compounds for electrical insulation Specification
8