The document describes the quality control process for cable manufacturing. It involves three stages of testing: raw material testing, in-process testing, and final stage testing. In-process testing checks parameters at various stages of production like wire drawing, stranding, insulation application. Tests include elongation, tensile strength, thickness. Final testing includes voltage testing, partial discharge testing, and measuring conductor resistance to ensure quality before shipping. Tolerance limits for various cable components are also defined. The quality control process aims to thoroughly inspect cables from raw materials to final product.

1. 1

2. 2
Quality Control (Q.C) – Checks
In QC department there are three sections to check the products staring from
the raw material used to produce the cable and during all various process of
production till the final stage to ensure the quality of the products and they are
confirming to the required specification before it shipped to customer
In Process Test Final Stage TestRaw Material

3. 3
1st Stage – Raw Material Test
•All raw materials are brought into the stores “to be tested” area and placed into
the warehouse for QC to process and test according to materials book & work
instruction for each material. These are then reported on and either accepted or
rejected as below chart explains in detail.
2nd Stage – In Process Test
The purpose of the “In Process Checks” is to maintain production standards
and ensure the compliance of product under manufacture is falling within the
tolerances set out & manufacturing specification

4. 4
Wires Drawing Process
Here following parameters have to be checked during this process to ensure a
quality wires are produced
1. Elongation test for 10 % of the drawn wires
2. Tensile Strength. for 10 % of the drawn wires
3. Wire Diameter for 10 % of the drawn wires
4. Ovality (roundness) for 10 % of the drawn
wires

5. 5
Stranding Process
Here the tests carried out are to check both the actual cross section area of
particular size as specified by standard & customer requirements through.
1. Resistance measurement
2. Weight measuring: One meter sample of the stranded conductor
shall be taken from the end of every drum & weighing for cross
check purpose only.

6. 6
Conductor (CU – AL )
Insulation (PVC – XLPE )
Metal Sheath ( Lead Alloy)
Inner Covering (PVC – XLPE)
Armoring
Outer Sheath (PVC – PE)

7. Insulation
Here a number of tests are carried out to measure the compliance of a
conductor’s insulation,
(1) Insulation thickness
(2) Spark Test
(3) Colour of Insulation
(4) Hot Set test for XLPE insulation

8. 8
Conductor (CU – AL )
Insulation Tipple layer (XLPE )
Outer Sheath (PVC – PE)
Inner Covering (PVC – XLPE)
Copper Screen
Armouring

9. 9

10. Medium Voltage (MV) & High Voltage (HV) Insulation
(1) Insulation Thickness
(2) Hot Set test
(3) Measuring the eccentricity of the insulation
(4) Measuring the Strippability of the insulation screen (for MV cables
only)
(2.5) check the transparent of the insulation (not required by the
standard)
Here a number of tests are carried out to measure the compliance of a
conductor’s insulation,
Insulation

11. Cu Tape
Screened Cable
11
there are two types of screening
(1) Copper Tape – thickness of tape and the % overlap of the tape
after being wound onto the cable.
(2) Copper Wire – actual number of wires and the diameter of
each copper strand
Screening

12. 12
Assembling
here are again a number of tests carried out to measure the
following
1) Overall physical diameter of assembled cable
2) Assembling Lay length of the cores
3) Filler (Polypropylene) – area of the filler

13. Inner Sheath
This is to measure the physical dimensions of a cut sample taken from
a manufactured cable, prior to final acceptance.
1. The thickness of the inner sheath
Armouring
This deals with the physical (mechanical) protection of the cables, this is done
in three different methods. Here the physical properties of the armouring are
tested.
1. Steel Wire – actual number of strands of the wires armour and wires
diameter
2. Steel Tape – the physical thickness of the tape and % overlap of tape
3. Aluminium Wire – actual number of strands of the wire armour and diameter
of wire

14. Final Sheathing
Here the physical properties are measured to check compliance
1. Thickness of outer sheath
2. Cable marking (Embossing) or printing
3. Spark test (e.g. for every 1mm thickness, this relates to a 6kV
electrical charge)
4. Colour of outer sheath
5. Length marking – stamped physically onto every 1 meter of length
sequentially
*Hot Set test
This is a test comprising of the following procedure, to test the cross
linkable (or curing) properties of the XLPE insulation,
1. A sample is cut from cable under test
2. The insulation is then stripped from the cable (XLP part)
3. Shaved down into a set thickness (i.e. 0.8 – 1.7 mm thickness)

15. 4. A “dumbbell” sample is stamped out for further testing.
5. Then a standard measured distance of 20 mm is marked off
6. When the total surface area is calculated and weight of 20N/cm2 is
selected
7. Then weighted load is attached to the sample and then placed in an
oven at 200’C for fifteen (15) minutes
8. Then the elongation (stretched) is measured and the elongation
percentage calculated a maximum of 175% is the maximum is allowed.
Note: For easy & fast procedures of performing the hot set test, loads for
all expecting thickness were calculated and prepared as weights pieces &
kept ready for using for this test as follows:
9.807Newton = 1000 g
1.000 Newton = 101.98 g
0.640 Newton = 65.26 g
CALCULATION OF LOAD FOR DUMBBELL TEST PIECES

16. Specified mechanical stress = 20 N/cm² according to
IEC 60811-2-1 clause 9 Width of the specimen = 4.0
Load
(Totally) (GR)
Actual Mechanical Stress
(Newton)
Area
(cm²)
Thickness
(mm)
Stress x 101.98 Area x 20 Thick. x Width Given
65.27 0.64 0.032 0.80
69.35 0.68 0.034 0.85
73.43 0.72 0.036 0.90
77.51 0.76 0.038 0.95
81.59 0.80 0.040 1.00
85.67 0.84 0.042 1.05
89.75 0.88 0.044 1.10
93.83 0.92 0.046 1.15
97.91 0.96 0.048 1.20
101.99 1.00 0.050 1.25
106.07 1.04 0.052 1.30
110.15 1.08 0.054 1.35
114.23 1.12 0.056 1.40
118.31 1.16 0.058 1.45
122.39 1.20 0.060 1.50
126.47 1.24 0.062 1.55
130.54 1.28 0.064 1.60
134.62 1.32 0.066 1.65

17. Size of Core
(mm²)
Outer Dia. of
Piece (mm)
(D)
Thick. of
Insulation
(mm)
Area of Cross
Section (mm²)
Area (cm²) (A) Actual Mech.
Stress (N)
Total
Load
(g)
1.5 2.96 0.70 4.97 0.0497 0.994 101.36
2.5 3.41 0.70 5.96 0.0596 1.192 121.55
4.0 3.95 0.70 7.14 0.0714 1.428 145.70
6.0 4.52 0.70 8.396 0.0840 1.68 171.30
Table # 2
CALCULATION OF LOAD FOR TUBULAR TEST PIECES

18.  
VOLTAGE TEST
PARTIAL DISCHARGE (FOR MV/HV CABLES)
CONDUCTOR RESISTANCE
TAN δ MEASUREMENT (FOR HV CABLES
MADE IN
EGYPT
18
3rd
Stage – Final test

19. 19
)A) High Voltage Test 3500Volts )3.5kV) for 5 minutes
A voltage of 3500 volts is passed between a single conductor and the
neutral (or earth), for a period of 5 minutes respectively. A voltage of 6.2kV
is also passed between the phases to test the insulation between the
different phases respectively.
Low Voltage Cables

20. 20
If this process of testing the individual core are successful passed and
there are no indication of any breakdown then the cable proceed to the
next test, which is
(B) Measuring the Conductors Resistance:
The conductor resistance of each cutting length on drum shall be
measured to verify the length of the cable as well as
1. HV test 3.5Uo voltage test is applied between the conductor & metallic
screen of each core for 5 minutes
2. Conductor resistance measurement (same as explained in LV cables)
3. Partial Discharge Test (PD test)
)B) Medium Voltage Cables

21. Partial Discharge test
The partial discharge phenomenon is known as a partial breakdown of
insulation. There are three type of PD which are:
1. Internal PD
2. Voids PD
3. Surface PD
The partial discharge is leakage charges from the conductor to the earth
through weak point in the insulation such as Voids, Contaminations in the
insulation, cavities in insulation or surface damage.
The purpose the PD test is to test if the minutist particles or voids are present
inside the XLPE insulation. This process is to measure the leakage of the
charge (Q) from the conductor to the metallic screen, through these weak
points. This test is measured in Pico-Column; the international standard is
anything ≤10 pC (10-12
Columns)

22. Conductor Insulation Insulation’s Screen
Prepared cable end length
C=
dt
dQ
Q = Charge t = time
For testing MV or HV cables electrically, cable terminals must be prepared as
shown in the above figure.

23. U is referred to any one of the following terms:
1.Line Voltage
2.Line to Line Voltage
3.Phase to Phase Voltage
U0 is referred to any one of the following terms:
1. Phase Voltage
2. Phase to neutral Voltage
3. Line to neutral Voltage
Voltage test for MV cables is 3.5 x U0, of the subject cables rated voltage
For example an 11kV cable, this means that U of this cable is 11kV,
therefore the U0
for this cable is:
3
11kV
=6.35kV
Thus the test voltage is 3.5x 6.35kV = 22kV test voltage rating to be applied for
5 minutes

24. S U M M A R Y
QUALITY CONTROL CHECKQUALITY CONTROL CHECK
PointPoint

25. IN-PROCESS PRODUCTIN-PROCESS PRODUCTIN-PROCESS PRODUCTIN-PROCESS PRODUCT
COPPER & ALUMINIUM WIRE DRAWINGCOPPER & ALUMINIUM WIRE DRAWING
 CONDUCTOR STRANDINGCONDUCTOR STRANDING
 INSULATION PROCESSINSULATION PROCESS
ELECTRICAL SCREENELECTRICAL SCREEN
 LAYING UP (ASSEMBLING)LAYING UP (ASSEMBLING)
FILLINGFILLING
ARMOURINGARMOURING
 OUTER SHEATHOUTER SHEATH
IN-PROCESS PRODUCT TESTIN-PROCESS PRODUCT TESTIN-PROCESS PRODUCT TESTIN-PROCESS PRODUCT TEST
SURFACE ( VISUAL )SURFACE ( VISUAL )
 DIMENSIONDIMENSION
 TENSILE STRENGTHTENSILE STRENGTH
 ELONGATIONELONGATION
 SPARK TEST ON INSULATION LINESPARK TEST ON INSULATION LINE
 HOT SET FOR XLPE INSULATIONHOT SET FOR XLPE INSULATION
 CABLE MARKINGCABLE MARKING
 PARTIAL DISCHARGEPARTIAL DISCHARGE
))For screened Cores of MV / HV CableFor screened Cores of MV / HV Cable

26. Function/Function/
DeptDept..
ProcessProcess ProcedureProcedure
Tech. Dept./ Prod.
Planning Dept.
According to spec. identified through
sales (contract review).
QC Engineer
Issue plan to QC supervisor/ Inspector.
QC Supervisor
For each manufacturing stage (as per
inspection & test plan).
Production
Supervisor
QC Inspector Attach tag to indicate status.
QC supervisor/
Inspector
- Sample frequency as specified in
In-Process Inspection.
- Continuous feedback about the trend
of the result to the operator.
QC Supervisor/
Inspector
- Identify rejected products as per
nonconformity procedure.
- Identify the accepted product.
QC Engineer
Quality Trends to be reviewed and
published in MRM and action plan to
be established to reduce
nonconformities.
IN-PROCESS INSPECTION & TESTINGIN-PROCESS INSPECTION & TESTING

27. CABLE FINAL TESTINGCABLE FINAL TESTING
11..ROUTINE TESTROUTINE TEST
Tests made on every finished length of cable or during
manufacture to ensure compliance with construction requirements
and demonstrate the integrity of the cable.
• Sampling criteria : 100 % of finished product
Tests made on samples of cable to represent production batches
and provide a periodic check on manufacturing consistency.
• Sampling criteria: 10% of total quantity order as per IEC 60502.
22..SAMPLE TESTSAMPLE TEST

28. 33..TYPE TESTTYPE TEST
Tests made during the development of a new grade of cable design to
establish performance characteristics.
• Sampling criteria: 1 sample of new design product.
FINISHED PRODUCT ROUTNEFINISHED PRODUCT ROUTNE
TEST (100% TESTTEST (100% TEST((
FINISHED PRODUCT ROUTNEFINISHED PRODUCT ROUTNE
TEST (100% TESTTEST (100% TEST((
VISUAL INSPECTION OF CABLES DRUMSVISUAL INSPECTION OF CABLES DRUMS
CONDUCTOR RESISTANCECONDUCTOR RESISTANCE
 VOLTAGE TESTVOLTAGE TEST
 PARTIAL DISCHARGE FOR MV & HVPARTIAL DISCHARGE FOR MV & HV
CABLESCABLES
INSULATION RESISTANCE (IF REQUIRED)INSULATION RESISTANCE (IF REQUIRED)
TAN δ FOR HV CABLES (10 % OF CUTTINGTAN δ FOR HV CABLES (10 % OF CUTTING
LENGTH)LENGTH)

29. Function/Function/
Dept.Dept.
ProcessProcess ProcedureProcedure
QC Inspector
From production Department
Check cable marking/
embossing
According to applicable Test
instructions
According to work order no.
QC Lab Non- electrical tests.
QC Engineer Stamp
"Passed QC"
QC Manager
To be reviewed and published
in MRM
FINAL INSPECTION & TESTINGFINAL INSPECTION & TESTING

30. QUALITY CONTROL DEPARTMENT
QUALITY OBJECTIVEES (1)
Date of setting: 01-03-2006
Date of implementation: 9/03/2006
1)CONDUCTOR RESISTANCE:
A. COPPER CONDUCTORS:
•From 1.5 mm² to 6 mm² -1.5 % + 0.0% from the maximum
specified value
•From 10 mm² to 35 mm² -1.0 % + 0.0% from the maximum
specified value
•From 50 mm² to 630 mm² -0.8 % + 0.0% from the maximum
specified value

31. B. ALUMINUM CONDUCTORS:
•From 10 mm² to 35.0 mm² -1.50% + 0.0% from the
maximum specified value
•From 50 mm² to 630 mm² -1.00% + 0.0% from the
maximum specified value
2(INSULATION:
A( XLPE Insulation:
•From 0.0 mm to 1.0 mm, maximum allowed +8.0% from the
average required
•From 1.1 mm to 1.5 mm, maximum allowed +6.0% from the
average required
•From 1.6 mm to 2.5 mm, maximum allowed +5.0% from the
average required
•More than 2.50 mm, maximum allowed +4.0% from the
average required

32. B( NYA & Flex Insulation:
• From 1.5 to 16 MM² conductor sizes, maximum insulation thickness allowed
is +6% from the average required
• From 25 to 70 MM² conductor sizes, maximum insulation thickness allowed is
+5% from the average required
3(INNER SHEATH
Only the minimum value has to be achieved & the maximum value shall be
95% of the nominal value.
Unless otherwise for some special specification or agreement between the El
Sewedy & customer to achieve both value (average & minimum), so in this
case the maximum allowed value should be +6 % from the average required
4(OUTER SHEATH
A( Sheath over Armouring or Direct sheath:

33. Only the minimum value is required to be achieved & the maximum value
shall be 95% of the nominal one.
B. Sheath over smooth surface or sheath for flex cables:
The maximum allowed value should be +8.0 % from the average required
5(CCV LINE (MV & HV Cables(
Conductor screen: The maximum thickness allowed +10 % from the
average required
Insulation screen: The maximum thickness allowed +3 % from the
average required
Insulation: The maximum thickness allowed +4 % from the average
required

34. InsulationInsulationInsulationInsulation AssemblyAssemblyAssemblyAssembly Inner sheathingInner sheathingInner sheathingInner sheathing
StrandingStrandingStrandingStranding
DrawingDrawingDrawingDrawing
Lead SheathingLead SheathingLead SheathingLead Sheathing ArmouringArmouringArmouringArmouring
Outer SheathingOuter SheathingOuter SheathingOuter Sheathing
34

35. - CABLE COST
90 % MATERIAL COST
10% PRODUCTION COST
- MATERIAL COST
MATERIAL PRICE
MATERIAL CONSUMPTION
- MATERIAL PRICE
REDUCE
CABLE COST
REDUCE
CABLE COST
How you can reduce the Material Price?
Look always for additional supplier.
Replace the actual material with a cheaper solution
MATERIAL CONSUMPTION
IN PRODUCTION
IN DESIGN DEPARTMENT

36. IN PRODUCTION:
MATERIAL OVERUSAGE
* Look for the tolerance –range for each production step, also for different
machine. (Quality Department). If the tolerance-range is too high, look for
the reason (bad material, old machine, bad measurement-equipment…
and
“make it better”
* Reduce set-up-length
* It will be helpful, that all necessary process data are written down for the
personal at the machine.
* Reduce scrap.

37. IN DESIGN DEPARTMENT:
* Design department is one of the important departments to influence the
cable cost.
*The design engineer must create cheapest cable design solution in
accordance with the customer specification.
* Look for “gaps” in the specification, it means, what is not required in the
specification.
During our 2 weeks discussion with many colleagues from
Production, quality, technical, planning and financial,
We found many points you can change it.
80% of your orders are with 8 Types:
The last 2 days we have made a cable re-design with the designer colleagues in
accordance the new points, Also 2 offers for 220 kV-cables.

38. 1) Reduce nominal thickness for inner and outer semiconductor layer.
2) Change the copper tape screening from 1 tape to 2 tapes.
3)Reduce the filler material in 3-core-cable with round conductor.
4)Fix the assembled cores with a tape as open helix.
5)In many specifications there is no average thickness required for bedding,
separation sheath. Therefore reduce the thickness.
6) Indicate in design sheet the different value: Nominal, Minimum, Average &
Practical Value.
7) Copper wire screen in mostly cheaper than copper tape screen.
8) Produce conductor for XLPE cable =10 kV only with dies.
9) Remove all fillers in 1 kV sector conductor – cables.
10) Reduce master batch colour in 1 kV cable with skin insulation
11)Manufacturing insulation for 1kV cable only in tube extrusion.
12) Try to use for 1kV cable as bedding a tape (instead extruded bedding).
13) Flat wire armouring is less in cost than round wire armouring. Check to
improve your armouring machine for flat wire.
14) Check your PVC- compound to increase the filler

39. It is really a great pleasure for me to work together with the very
friendly and well experience people in EL SEWEDY CABLES
THANKS
Eng’r. Mohsen Al Tandi
Quality Control Manager
Arab Cables Company