T A B L E – T 1
T E S T S A N D I N S P E C T I O N C A B L E P C U T A N D P C U T - A
No. Test Scale MOC Requirements Test
Method
G 20:10:001:01 Clause Ref. Other Refs Defined a. Tests On Completed Cable Lengths (Manufacturer-100 %) MOC Inspector – 10 % Of Drums Of Each Type And
Size Of Cable Selection At Random
1 Conductor Resistance at 20 °C 5 % of Pairs in each unit Conductance Ω/Km max: 0.4 150 0.5 96 0.65 57 0.9 30 IEC – 28 IEC – 344 Clause 15.2 2 Resistance Unbalanced at 20 °C 5 % of Pairs in each unit Max. 2 % of loop resistance DC Bridge IEC-708-1 Clause 24 Clause 15.3 3 Conductor Diameter 5 % of Pairs in each
unit 0.4 to 0.9 mm Direct Measurement Clause 5.2
4 Mutual
Conductance 1 pair of each unit 2 Micro MΩ/Km
MOC Requirement
1000 Hz at 20 °C Clause 15.7 5 Mutual Capacitance 10 % pairs of each
unit Max. Av. 55 nF/Km Ind. Max. 58 nF/Km IEC 189-1 Clause 5.4 Clause 15.4 6 Capacitance Unbalance 10 % pairs of each layer Per 160 m Length Mean 100 pF Max. 250 pF IEC 189-1 Clause 5.5 Clause 15.5 7 Insulation Resistance 5 % of conductance in each unit 10,000 MΩ..Km at 20 °C Minimum IEC 189-1/5.3 A to B/A to earth, B to earth with 500 VDC up to 1 min. All other conductors and sheath earthed
Clause 15.6
8 Dielectric Strength All tested drums
Between conductors 500
VAC for 3 seconds All conductors and sheath 1500 VAC for 3 seconds
IEC 189-1 Clause 5.2
Al conductor bonded together
Clause 15.8
9 Gas Pressure Test All tested drums Max. leakage 100 g/cm 2
after 12 hours
Pressurised at 4
kg/cm² Clause 11.111.2
10 Cable Over all
Diameter All tested drums See Cable Spec. Direct Measurement
Table 7 Un-armoured Table 10 for Armoured 11 Identification and Length marker on Sheath
All tested drums
Type, size, gauge at 1 meter intervals
White lettering on sheath
Appearance Check G 10:10:01 Clause 11 MOC Common Technical Requirements 12 Cable End Treatment All completed Drums
i. Valve at inner end ii. Cable banded in red at
clockwise (outer) end. Green at inner (anticlockwise) end. iii. Pulling eye Fitted at
outer end. Physical Check G 10:10:01 Clause 17.2 MOC Common Technical Requirements Clause 5.1.7 And 5.2.2
13 Cable Drum All completed Drums
1. Pressure Maintenance at 650 g/cm2.
2. Sign writing No., Pressure Measured and visual checks.
G 10:10:01 MOC Common Technical
3. Length verification from sheath marking.
b. Tests During Manufacture (Random Sampling Tests)
14 Conductor
Elongation to Break
4 tests for each type & size of cable Cond. Minimum 0.4 15 % of length 0.5 15 % of length 0.65 20 % of length 0.9 20 % of length IEC 189-1 Clause 3.3 Length of specimen-200 mm Jaw Speed ± 20 mm/min. Clause 16.1 15 Conductor Tensile Strength
4 tests for each type & size of cable
Minimum 20kg/mm² IEC 189-1
Clause 3.3 Clause 16.1
16 Jointed Conductor Sample
1) Tensile Strength Min.18 Kg/mm2 2) Elongation 90 % of un-jointed conductor 3) Resistance 105 % of un-jointed similar length conductor ISO R402 1) 250 mm Length sample 2) 250 mm Length sample 3) 150 mm Length sample G 10:10:01 Clause 6.6 17 Vacuum Indicator
Test All Lengths Partial Vacuum
Measured 12 hours after sealing of cable ends immediately after sheathing Clause 11.11.1 18 Lead Sheath All Length Sample
Seamless with no joints or cracks
Expandable by 50 %
Clause 11.1 Clause 16.13 19 Identification Tape Each type of cable
Manufacturer’s name, type, size, gage at 150 mm intervals
Physical Check Clause 10
20 PE Jacket Tensile Strength 1) Normal 2) After Aging 5 samples Dumbbell Test Pieces 1) Min. 1 Kg/mm2 2) Max. change 20 %
after heating for 48 hours at 100 °C IEC 538 Clause 3 Clause 16.4.2 G 10:10:01 Clause 10.4 21 PE Jacket Elongation 1) Normal 2) After Aging 5 samples Dumbbell Test Pieces 3) Min. 400 % 4) Max. change 25 %
after heating for 48 hours at 100 °C
IEC 538
Clause 3 and ASTM D-412 Speed of Jaw separation 350 –500 mm/min Clause 16.4.2 G 10:10:01 Clause 10.4 22 Thickness of
Insulating Paper Sample 0.04 mm Minimum Direct Measurement Clause 6.3 23 Tensile Strength of
Insulating Paper Sample
Min. 1.8 Kg i.e. 0.07 Kg/µm thickness of paper 25 mm wide 0.25 mm thick test piece Clause 16.2 24 Lead Sheath
Thickness Each Cable Type See Specification Direct Measurement
Table 7 Un-armoured Table 8 & 9 Armoured
25 PE Jacket Thickness Sample of each
cable type See Specification Direct Measurement
Table 7 Un-armoured Table 10 Armoured 26 Diameter of Finished Cable Core Sample of each
cable type See Specification Direct Measurement
Table 7 Un-armoured Table 10 Armoured 27 Twinning and lay:
27.1 Lay of Conductor Each Length Different for adjacent
pairs. Max. 200 mm Measured Clause 7
27.2
Colour marking &
28 Stranding: 28.1 Formation of Unit 28.1. 1 Rayon or Cotton Whipping of Layers in Unit
Each Length Minimum 3 Strands Visual Clause 8.1.2
28.1. 2
No. of Pairs in each
layer of Units Each Length See Specification Visual Clause 8.1.1
28.1. 3
Helical Paper tape
Lapping of Units Each Length See Specification Visual Clause 8.1.3
28.1. 4
Number of Units on
Lapping Tape Each Length
At intervals of Max. 50 mm Visual Clause 8.1.3 28.1. 5 Rayon or Cotton Whipping of Complete Units
Each Length See Specification Visual Clause 8.1.3
28.1. 6
Stranding of Layer in
Units Each Length
Same Direction for All
Layers Visual Clause 8.1.6
28.2 Formation Of Cable: 28.2.
1
Whipping of Units in
Layers Each Length See Specification Visual Clause 8.1.8
28.2. 2
Number of Units in
Layers Each Length See Specification Visual Clause 8.1.6
28.2.
3 Core Wrapping Each Length
2 Paper Wrappings 0.12
mm thickness 30 % overlap Visual Clause 9.1
28.2. 4
Colour of Core
Wrapping Each Length
Lead Alloy-E Green
Lead Alloy-B Red Visual Clause 9.1
29 Armoured Cables Only:
29.1 Diameter of Steel
armouring Wire Each Length
See Spec
Range: 3 – 6 mm Measured Table-8
29.2 Lay of Steel
Armouring Wire Each Length
15 – 20 times
θ Bedding Measured Clause 12.2.2
29.3
Thickness of Steel Armouring Tape (If Applicable)
Each Length 0.5 – 1.0 mm
See Spec. Measured Table – 10
29.4
Overlap of Steel Armouring tapes (If Applicable)
Each Length 33 % Measured Clause 12.4.4
29.5
Galvanised Coating on Steel Armouring Wire
Each Length Min.: 200 g/m2 ISO - 1460 G 10:10:01
Table-5 29.6 Thickness of
Bedding Each Length See Spec. Measured Tables – 8&10
29.7 Thickness of Serving
Outer Each Length See Spec. Measured Tables – 8&10
30 Resistivity of Copper Sample 0.017241 Ω at 20 °C IEC-28 G 10:10:01
Clause 6.3 31 Lead Sheath
Composition Each Cable Type Alloy E or B Chemical Analysis
G 10:10:01 Clause 9.3 32 PE Compound Sp. Gravity Sample Medium Density Max. 0.926 – 0.940 IEC-538 Clause 5.1 G 10:10:01 Clause 10.2 33 PE Carbon Content Sample 2.5 ± 0.5
(By Weight)
IEC-538
Clause 5 Clause 13.5
34 PE Melt Flow Index Sample Max. 0.5
IEC-538 Appendix (B) Method-C
G 10:10:01 Clause 10.4
35 Brittle Temperature Failure
5 Specimens at –
60 °C Nil Failure ASTM D-746
G 10:10:01 Clause 10.4 36 Environmental Stress Crack Resistance 10 Specimens after 48 hours conditioning
Nil Failure at conditioning temperature of 50 °C Reagent Igepal CO-630 in 105 Aqueous solution ASTM D1693 See Note-1 on Preparation of Test specimens G 10:10:01 Clause 10.4 Note 1
E X P L A N A T O R Y N O T E 1. NOTE 1: ENVIRONMENTAL STRESS CRACK RESISTANCE TEST
1.1. The test detailed in IEC Publication 538-A Procedure B shall be substituted for that detailed in ASTM D-1693 when the moulded sheet notch dimensions for medium density polyethylene are determined (See Note in IEC 538- A Sub-Clause 2.6.2)
1.2. The following procedures for the preparation of the moulded sheet for environmental crack resistance tests on PE Sheets are detailed as an aid and clarification to the procedures detailed in ASTM-D-1693.
1.3. Preparation Of Moulded Sheet For Crack Resistance Test (Preparation Of The Mould)
1.3.1. Using a solvent such as trichlaro-ethylene, throughly clean a piece of smooth aluminium foil 230 mm × 200 mm. Place this parting sheet on a backing plate of smooth hard aluminium 230 mm × 200 mm × 6
mm or more thick, having a thermometer well sunk into one edge extending to the centre of the plate.
On this is placed a spacing frame consisting of a 230 mm × 200 m × 3.30 mm thick plate of stainless steel or other suitable material having a rectangular hole 180 m × 150 mm with its internal corners rounded to a radius of 3 mm.
Place a calculated quantity of polyethylene compound in the opening of the spacing frame in such a way that the material will flow from the centre towards the sides of the frame and avoid leaving bubbles in the moulded sheet. (The approximate quantity of polyethylene required in grams is equal to 27 × density × thickness (in m) + 2. Cover the charge with a second backing plate also fitted with a thermometer. 1.3.2. Moulding
Preheat the press to 170 °C. Insert the mould unit, prepared as above and close the press using light pressure only. Hold until the thermometers indicate that the material has reached a temperature of 165 – 170 °C (Approximately five minutes) and then increase the pressure to a force of 16,000 Kg and maintain it thus for two minutes. Allow the temperature to drop to 340 °C in approximately five minutes before releasing the pressure.
Remove the backing plates without disturbing the aluminium parting sheets of the frame. This constitutes the annealing unit.
1.3.3. Annealing Apparatus
A circulating-air oven, capable of maintaining a temperature of 145 ± 20 °C fitted with a device for lowering the temperature at a constant rate of 5 ± 0.5 °C per hour down to at least 400 °C.
1.3.4. Separator plates
Smooth aluminium plates 230 mm × 200 × 1.5 mm hick. 1.3.5. Follow-Up Plates
Smooth aluminium plates 145 mm × 170 m × 1.6 mm thick. 1.3.6. COVER PLATES
A smooth brass plate 230 mm × 230 mm × 10 mm thick with a thermometer well drilled into one edge and extending to the centre of the plate.
Annealing
Stack the annealing units horizontally on a shelf or suitable support so as to permit free circulation of air on all sides of the stack as follows:
Place a separator plate at the bottom. Centre a follow-up plate plus a separator plate on each unit. Place the cover plate on top of the stack. The follow-up plates are extended to fit in the depression of the annealing unit to maintain good contact between the parting sheets and the polyethylene during the expansion on melting and contraction on cooling.
After assembling the stack of annealing units in the oven, heat the oven until the thermocouple inserted in the brass cover plates records 145 °C.
Maintain the oven at 145 ± 2 °C/hour, then begin cooling at 5.0 ± 0.50 °C/hour by means of a mechanical device. The actual cooling rate should be recorded by a graphical recorder.
Remove the annealing units when they have reached 40 °C or less, and remove the parting sheets and moulding frames. A properly prepared sheet should contain no bubbles or sink marks except possibly near the edge. Sheets containing such blemishes may be reprocessed at once.
1.3.7. Determination Of Residual Strain
Preheat the petri dish containing 3 - 6 mm of talc to 140 ± 2 °C in an air oven. Cut two specimens 13
mm by 38 m from different parts of the test sheet with their long axes perpendicular to each other. Place
these specimens on the preheated talc, and maintain at 140 ± 20 °C for 30 minutes, then remove the dish with the specimens and allow to cool to room temperature. A specimen that exhibits less than 10 percent shrinkage as measured by a scale readable to 0.1 mm and whose surface remains smooth and regular
indicates a satisfactory test sheet. The outside 6 mm of such sheets should be trimmed and discarded before the sheet is used.
