C&I Cables Tests

© LANCO Group, All Rights Reserved© LANCO Group, All Rights Reserved
POWEREPC INFRASTRUCTURESOLAR RESOURCES
Lanco Babandh Power Ltd
(C&I Cables Testing Methods)
PRATYUSHA KHANDELWAL
Source : Thermo Cables Limited, Hyderabad: 19.Nov.2012-23.Nov.2012

© LANCO Group, All Rights Reserved
Types of Cables:
• Power Cables/Control Cables
• Instrument/TC/Signal Cables
Note: Only Instrument cables have drain wires

Material used in Cables:
• TYPE: Y13 = Conductor Insulation(VDE 0207PT4)
• TYPE: A = Conductor Insulation
• XLPE = Conductor Insulation
• TYPE: YM1 = Inner Sheath (VDE 0207PT5)
• ST1 = Outer Sheath
• ST2 = Outer Sheath
*Note: Credentials validity must be up to 5 yrs approved by CPRI/NABL/NTH etc

Nomenclature:
Ex: 3C/P/T/Q 16 SQ MM 1100V FRLS TCL 2012 315M
Job ID: XXXXXX
Customer No. DVWS
Job No./ASC: 303468
Size: 8P x 0.5 sq.mm
DRM No. 1004883
QTY: 465 M
*ASC= Armoured Screen Cable

Tests for Cables:
Type/Routine Tests: (100% of the given lot)
1) HV Test/High Pot. Test
2) Conductor Resistance Test
3) Drain Wire Resistance Test
4) Insulation Resistance Test

Tests for Cables:
Acceptance Tests: (10% of offered lot of each cable size as applicable)
1) Construction detail verification(Conductor/Insulation system/ Pairing/
Laying/Pair/Overall Shielding/Inner sheathing /Armoring/Outer sheathing)
2) Conductor Resistance Test
3) Capacitance, Inductance & L/R Ratio Test
4) Tensile strength and elongation at break for insulation and sheath before and
after ageing
5) Thermal Stability Test
6) Cross Talk/Attenuation Test
7) Insulation Resistance measurement
8) Insulation thickness measurement
9) Color identification of cores
10) Annealing Test
11) Volume Resistivity Test
12) Hot Deformation Test

Acceptance Tests:
FRLS & ART:
1) Oxygen Index Test.
2) Temperature Index Test.
3) Smoke Density Test.
4) Flammability.
5) Swedish chimney/Flame Retardant Test.
6) Acid gas generation test.
7) Anti rodent test.

HV Test:
IS : 10810 Part 45
• HV Tester
• ForControlCables: 3kV ACrms for 5 minutes(C-C)
3kV ACrms for 5 minutes(C-Armour)
• ForTC/InstrumentCables: 1kV ACrms for 1 minutes(C-C)
1kV ACrms for 1 minutes(C-Screen)
*Note: Drain wires are only present in Instrument cables

Conductor Resistance & Drain Wire Resistance Test:
• BS: 5308 Part-2
• IS: 10810 Part-5
• Digital Ohm Meter
• Probe Calibration Test- 0.0 at NTP
• At 20°C, R= [Rx.k.1000/L]; Ω/km [max. 36.6]
where, k= 250/(230+T)
*Drain wire: 30 Ω,max /Conductor Wire: 36.6 Ω,max

Insulation Resistance Test:
• IS: 10810 Part-43
• Insulation Tester
• IRconstant = LxR/[1000Log10(D/d)]; MΩ-km
• Min. 100MΩ/km
• C-C
• C-Shield
• Insulation
• L/R

Capacitance, Inductance & L/R Ratio Test:
• BS: 5308 – I & II
• Digital LCR Q Meter
• Frequency is set at 1kHz
• OC & SC test is done
• Capacitance b/w cores= Cc x 1000/L in nf/km [max. 250]
• Capacitance b/w core to shield + armor = Cs x 1000/L in nf/km
[max. 400]
• Inductance = L x 1000 x 1000/L in mH/km [max. 1]
• L/R = obs. Inductance/loop resistance; µH/Ω [max. 25]

continued…
PARAMETER PVC INSULATION XLPE/LDPE INSULATION
Capacitance b/w cores Max. 250 nf/km Max. 100 nf/km
Capacitance b/w core-shield Max. 400 nf/km Max. 400 nf/km
Inductance for signal cables Max.1mH/km Max.1mH/km
Inductance for TC cables Max. 4mH/km Max. 4mH/km
L/R ratio up to 1 mm² Max. 25µH/Ω Max. 25µH/Ω
L/R ratio 1- 1.5 mm² Max. 40µH/Ω Max. 40µH/Ω
L/R ratio 2.5 mm² Max. 50µH/Ω Max. 50µH/Ω

Ageing Test:
• IS: 10810 Part-11
• Tensile strength and elongation at break for insulation and sheath before and after ageing is done.
• 7 Days test at specific temp. of 80°C, 100°C etc
• Sheath-dumb-bell shape & Insulation-tubular shape; each sample of ≥ 100mm is taken.
• 20 mm marking is done on each test sample and tested at 50kg wt. tensile & elongation tester.
• Tubular Cross sectional Area, A = ∏/4[ D² – d²]; mm²
• Dumb-bell Cross sectional Area, A = width x thickness; mm²
• T.S. = BL x 9.8/ A; N/mm²
• % Elongation = [L-L0]/L0 x 100 in %
• Variation in T.S. = [TS0 – TSx]/TS0 x 100 in %
• Variation in Elongation = [EL0- ELx]/EL0 x 100 in %
Note: BL at fractured point shall not be greater than 250 mm/min.
Material T.S. % Elongation
PVC 12.5 N/mm² min. Min. 150 %
LDPE 10 N/mm² min. Min. 300%
XLPE 12.5N/mm² min. Min. 200%

Ageing Test: continued…
Material Variation in T.S. Variation In Elongation
TYPE A Max. ± 20% Max. ± 20%
TYPE C Max. ± 25% Max. ± 35%
TYPE ST1 Max. ± 20% Max. ± 20%
TYPE ST2 Max. ± 25% Max. ± 25%
TYPE ST2 with FR/FRLS Max. ± 25% Max. ± 25%
XLPE Max. ± 25% Max. ± 25%
Material Set Temperature Duration of Test
TYPE A 80±2 °C 7 Days
TYPE C 135±2 °C 7 Days
TYPE ST1 80±2 °C 7 Days
TYPE ST2 100±2 °C 7 Days
TYPE ST2 with FR/FRLS 100±2 °C 7 Days
XLPE 135±2 °C 7 Days

Thermal Stability Test:
• IS : 5831-1984
• Digital Temperature Controller
• Temp.: 200°C
• Time: 40 Minutes
• PH paper color changes
Type of Material Test Duration
TYPE A, FRLS, PVC 80 minutes( min.)
TYPE C 100 minutes( min.)
TYPE ST1, FRLS 40 minutes( min.)
TYPE ST2, FRLS 80 minutes( min.)

Cross Talk/Attenuation Test:
• LF Source & Selective Level Meter
• Frequency is set at 800Hz, Voltage = 10mV
• Attenuation = 20 log10[Vmax/Vmin]; dB
• It should be ≤ 1.2 dB(max.)
• Cross Talk ≥ 60 dB(min.)

Annealing Test:
• Test Sample: L1 = 250 mm marked
• %age = [(L2 – L1)/ L1] x 100
• Annealing Test for conductor must be min. 18%
• Ex: L1 : 250, L2 : 310
24%

Volume Resistivity Test/Water Immersion Test:
• IS: 10810 Part-45
• VR is tested at ambient temp. and at rated temp. of 70°C
• Voltage = 500V
• Test Sample, L = 3.5 mtrs
• VR = [observed resistivity x 2∏ x L x e⁸]/ log(core dia./conductor dia.); MΩ-cm
Material At ambient temp.(27°C) At rated temp.(70°C)
PVC Type A Min. 1 x 10^13 Ω-cm Min. 1 x 10^10 Ω-cm at 70°C
PVC Type A, FRLS Min. 1 x 10^13 Ω-cm Min. 1 x 10^10 Ω-cm at 70°C
PVC Type C Min. 1 x 10^13 Ω-cm Min. 1 x 10^10 Ω-cm at 85°C
XLPE Min. 1 x 10^14 Ω-cm Min. 1 x 10^12 Ω-cm at 90°C
LDPE Min. 1 x 10^15 Ω-cm Min. 1 x 10^12 Ω-cm at 70°C

Smoke Density Test:
• ASTM D 2843
• Smoke Density test apparatus
• Pressure gauge pointer
• Gas flow at 40 psi or 2.8 kg/cm²
• % of light absorbed at 15 sec interval for 4 minutes ie 16 values.
• Rating = [ (Sum of 1 to 15 values) x 2 + 16th value] / 32 in %
• 60% for FRLS PVC (max.)
• 20% for ZHFR (max.)
• Vdc = 5.8V
• Ex: For a sample, the absorption % is as follows:
1 min : 14%
2 min : 28%
3 min : 31%
4 min : 29%

Swedish chimney/Flame Retardant Test:
• IS: 10810 Part-61 & SS 424-1475 F3
• Specimen Length: 850 mm and ext. dia. should not exceed 35
mm
• Stop watch
• Unaffected portion from top shall be min. 300mm
• Ex: Test Sample Dia, D =20 mm
Ethanol Qty(ml) = Time(min) x 20 = [1+D/5] x 20
= 100 ml
Total Length = 850 mm; Undamaged sample after test= 610 mm

Oxygen Index Test/ Temperature Index Test:
• ASTM D 2863
• Oxygen is 100% and N2 is 0%
• Flame is inserted
• OI = 29%(min.) and Temp. : 30°C;
• At 32, 32.5, +0.5°C likewise increases it.
• TI, at 50°C, 80°C
• TI = 250°C(min.)

Flammability:
• IEC: 332 Part-3
• Ladder length : 4 meters
• Cable length : 2.5 meters
• Time : 20 minutes
• LPG flow: 0.25 kg/cm²
• Air flow: 2.4 kg/cm²
• Sample Result: 1.35 mtrs burned

Acid gas generation test:
• IEC: 60754-Part I
• Test Sample: 1 gms
• Electronic Balance
• Digital Temp. Controller
• Pressure air flow meter
Procedure:
• 4 gm NaOH+ 1 ltrs distill water is made
• 440ml soln of NaOH is made.
• 200ml soln is taken out seperately.(Original Sample)
• One sample is put at 800°C for 40 minutes (Test Sample)

Acid gas generation test: continued
Titration:
• 200ml soln. of each is taken out from 440ml NaOH+ 1000ml distill water
• 4ml Nitric Acid is added in both samples
• 3ml Nitro Benzene(C6H5NO2) is added in both samples
• 20ml AgNO3 is added in both samples
• 1ml (40% ferric ammonium) is added in both samples
• 0.1 M Ammonium Tryo Cyanate, NH4CNS (50ml) filled in burate
• Now, original sample is stirred, and burate valve is opened.
• Original Soln. color changes at X ml and Test soln. color changes at X+Y ml
• % of HCL can be max. 20 in mg/g

Acid gas generation test: continued
• Ex: Cable: 3C x 16 sq.mm
• Test Sample: 1.0071 gms
• Original Soln.: 23ml & Test Soln.: 37ml
• HCL % = 3.65 x 0.1 x (B-T) x (1000/200)/Weight of test sample
= 3.65 x 0.1 x (23-14) x (1000/200)/ 1.0071
= 16.30 %

ART: Anti rodent & termite repulsion test:
• IS : 5831-1984
• Ash of cable is taken.
• Sodium Sulphide flakes(fused), Na2S.xH2O are mixed with distill water in
other bowl.
• Ammonium Acetate soln. + Distill water + Ash all the three are put in oven
for 10 minutes at 80 °C
• After 10 minutes, sample is filtered and mixed with H2SO4.
• We get brown spots, it means Lead is present in the given sample.

Important Cable Testing Standards:
• IS 5831: PVC Compound
• BS 7655: ZHFR
• IS 8784, IEC 60584-1&3, ANSI MC 96.1: TC Cables
• IS 10810: Methods of tests for cables
• BS 5308-I&II : L/R Ratio
• BS 5308P2, IS 10810P5: Drain wire test
• IS 5831, IS 10810P60: Thermal Stability
• ASTM D 2863: Oxygen Index & Temp. Index Test
• ASTM D 2843: Smoke Density Test
• IEC-60754P1: HCL gas test
• IS 10810P62, IEC 332P3: Flame Retardance Test for bunch of cables
• IS 10810P61 & SS 424-1475: Swedish Chimney Test
• IEC 332P1: Flammability Test
• IEC 60331: Fire Survival Test
• IS 10810P12: Shrinkage Test
• IS 10810P10: Loss of mass
• IS 10810P14: Hot shock Test
Data Sheets
Test Certificates

PK
p.khandelwal@lancogroup.com
9/14/2015 12:12 AM

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