Study of Pulling Lubricant Interaction
with LSZH Jacket Materials
(Update Oct 2006)
John M. FeeAmerican PolywaterStillwater, MN USA
Hydro Plant LSZH Jacket Failure
• Generator lead cables at a hydro plant• 2000 kcmil, 15 kV, EPR/LSZH cables (two per
phase)• Cables rise ~100 feet to cable spreading room• Supported at top by wire grip (improperly sized
and applied)• Short sections of tray before exiting to switchyard• Wood spacer blocks in tray (improperly sized)• Conduit on both sides of tray results in pulling
lubricant residue• Failure observed in tray and at grip
Hydro Plant LSZH Jacket Failure
• Cable spacer block grabs cable jacket• Tension introduced by close proximity cable hang
Hydro Plant LSZH Jacket Failure
• Jacket under stress from hanging grip• Lubricant residue from pulls into duct banks on both sides
LSZH Jacket Failure Observations• Jacket under stress where it tore• No extraordinary environmental conditions• Cable under electrical load – warm• Not contained in conduit – so cables were dry
– no lubricant “reflux”• Tension on jacket estimated at 500 to 1000
psi• IEEE 1210 testing of actual lubricant used on
failed cables showed aged tensiles of 800 to 1000 psi and low elongations of 20 to 30%
• LSZH jackets have been pulled into conduit for many years without significant problems –physical stress on jacket produced this failure
IEEE 1210 – 2004Table 1
858585
After immersion test at 50 °C ± 1 °C for 30 daysRetained tensile and elongation at rupture, %
minimum of immersed in water/air and heat-aged comparison
121168
85
75
85
121168
75
60
85
100168
75
60
85
Immerse at (°C ± 1 °C )Immerse for (hours)Retained tensile strength, % minimumof unimmersed and unaged comparison
Retained elongation at rupture, % minimumof unimmersed and unaged comparison
Retained tensile strength and elongation at rupture, % minimum of immersed in water/air and heat-aged comparison
ThermosetType 2
ThermosetType 1
ThermoplasticType 1
Low Smoke Halogen Free Properties
IEEE 1210 Tests
1. ICEA/NEMA jacket aging requirements2. Test “refluxes” jacket in lubricant3. Secondary lower-temperature, longer-aging test 4. Water vs air-aged control5. Sample pulling speed – 50 mm/min vs 500
mm/min6. 100°C vs 121°C7. Reflux test of jacket in lubricant - more severe
than conditions where actual failure occurred.8. Physical strength focus seems right based on
nature of field failure.
LSZH Jacket Study to IEEE 1210
• 27 jackets designated A to AA• 17 plaques, 7 tapes, 3 Jackets• 20 thermoplastic, 7 thermoset• Primarily inorganic hydrate loaded types• All pulled at 50 mm/min• Data presented are for a water-aged
comparison sample• Plaque sample variability based on
preparation
Tensile at Break
0
500
1000
1500
2000
2500
3000
3500
4000
N F C M E R S H D Q W B Z O I T G Y L AA X U A V P K J
Jacket Compound Designation
PS
I
Non-Aged Sample Tensiles
• Samples had non-aged tensile from 600 to 3500 psi (4 to 24 Mpa)• Sample ave tensile of 1582 psi (10.9 Mpa)
Elongation at Break
0%
100%
200%
300%
400%
500%
600%
700%
I E C M Z O R S Q X T AA P H U V A W J N L K Y B G F D
Jacket Compound Designation
Elo
ngat
ion
(%)
Non-Aged Sample Elongations
• Samples had non-aged elongations from 30% to 575%• Sample ave elongation of 155%
0
500
1000
1500
2000
2500
3000
3500
4000
N F C M E R S H D Q W B Z O I T G Y L AA X U A V P K J
Jacket Compound Designation
Tens
ile (p
si)
0
100
200
300
400
500
600
700
Elo
ngat
ion
(%)
TensileElongation
Sample Tensile / Elongation Comparison
• Elongation and tensile not correlated• Elongation property shows greater variability
0%
20%
40%
60%
80%
100%
120%
140%
S W U T J FAA A B Y R V Q I D G K Z P O L M X C E H
Jacket Compound Designation
Ten
sile
Ret
aine
d (%
)
100° C50° C
Sample Tensile Retention (vs Non-Aged)Water-Aged (7 day @ 100°C & 30 day @ 50°C)
• At 100°C - Ave tensile retention of 91% - range from 56% to 125%• At 50°C - Ave tensile retention of 98% - range from 84% to 118%• Less robust samples in 100°C water are less affected by 50°C
0%
20%
40%
60%
80%
100%
120%
140%
160%
180%
200%
H F T S U Q E Y J D O Z C V AA B A I M P G L N W X K R
Jacket Compound Designation
Elo
ngat
ion
Ret
aine
d (%
)
100° C50° C
Sample Elongation Retention (vs Non-Aged)Water-Aged (7 day @ 100°C & 30 day @ 50°C)
• At 100°C - Ave elongation retention of 71% - range from 8% to 118%• At 50°C - Ave elongation retention of 93% - range from 30% to 173%• Larger changes than tensile
Observations – Control Samples
1. There is no typical “LSZH” jacket.2. There are significant differences in base
physical properties and temperature / water resistance of these materials.
3. Some samples notably more robust in 100°Cwater-aging. Differences not as great at 50°C.
Some lubricants severely affected jackets materials. Continued testing was only done on lubricants that
maintained enough jacket integrity to support testing
0%
20%
40%
60%
80%
100%
120%
140%
S U T AA L W X V A Q F D Z I M O P G B R Y E N C H
Jacket Compound Designation
Tens
ile R
etai
ned
(%)
Tensile Retention ComparisonLubricant A (7 day @ 100°C) vs Non-Aged
• Lubricant A (100°C) – 8 out of 25 specimens met 75% retention• Lubricant A (100°C) - Ave tensile retention of 69% - range 25% to 116%
75%
0%
100%
200%
300%
400%
500%
600%
F S H C U Q AA I T D B E G Z P Y L A V R X W N M O
Jacket Compound Designation
Tens
ile R
etai
ned
(%)
Elongation Retention ComparisonLubricant A (7 day @ 100°C) to Non-Aged
• Lubricant A (100°C) - 17 out of 25 specimens met 60% retention• Lubricant A (100°C) - Ave elongation retention of 128% - range 20% to 478%
60%
0%
20%
40%
60%
80%
100%
120%
U T S L X AA V M D Q O Z P A I W G E F N R B C H Y
Jacket Compound Designation
Tens
ile R
etai
ned
(%)
Tensile Retention ComparisonLubricant A (7 day @ 100°C) to Water-Aged (7 day @ 100°C)
85%
• Lubricant A (100°C) – 5 out of 25 specimens met 85% retention• Lubricant A (100°C) - Ave tensile retention of 75% - range 38% to 104%
0%
100%
200%
300%
400%
500%
600%
700%
800%
C S I AA Q G U B P D F L Z R E A X T W V Y N H M O
Jacket Compound Designation
Tens
ile R
etai
ned
(%)
Elongation Retention ComparisonLubricant A (7 day @ 100°C) to Water-Aged (7 day @ 100°C)
85%
• Lubricant A (100°C) - 21 out of 25 specimens met 85% retention• Lubricant A (100°C) - Ave elongation retention of 182% - range 43% to 726%
0%
20%
40%
60%
80%
100%
120%
140%
T M V X U N S I L O Q W E Z A G D C F H B Y P
Jacket Compound Designation
Tens
ile R
etai
ned
(%)
Tensile Retention ComparisonLubricant A (30 day @ 50°C) to Water-Aged (30 day @ 50°C)
85%
• Lubricant A (50°C) – 18 out of 23 specimens met 85% retention• Lubricant A (50°C) - Ave tensile retention of 93% - range 38% to 104%
0%
100%
200%
300%
400%
500%
600%
T I Q Z C E L H G D F A B O Y U V W S M N X P
Jacket Compound Designation
Tens
ile R
etai
ned
(%)
Elongation Retention ComparisonLubricant A (30 day @ 50°C) to Water-Aged (30 day @ 50°C)
85%
• Lubricant A (50°C) - 18 out of 23 specimens met 85% retention• Lubricant A (50°C) - Ave elongation retention of 150% - range 45% to 545%
0%
20%
40%
60%
80%
100%
120%
140%
S T W J U AA Y F A G V B K M D Q R O X I L P N Z C E H
Jacket Compound Designation
Tens
ile R
etai
ned
(%)
Tensile Retention ComparisonLubricant B (7 day @ 100°C) to Non-Aged
75%
• Lubricant B (100°C) – 24 out of 27 specimens met 75% retention• Lubricant B (100°C) - Ave tensile retention of 87% - range 51% to 119%
0%
20%
40%
60%
80%
100%
120%
140%
H F S T O C Q E U Z J Y AA X B G D V P I A N W L K M R
Jacket Compound Designation
Tens
ile R
etai
ned
(%)
Elongation Retention ComparisonLubricant B (7 day @ 100°C) to Non-Aged
60%
• Lubricant B (100°C) - 19 out of 27 specimens met 60% retention• Lubricant B (100°C) - Ave elongation retention of 78% - range 17% to 127%
0%
20%
40%
60%
80%
100%
120%
N M T X S G O L Y P K D E AA C V W F J Q R H I Z A U B
Jacket Compound Designation
Tens
ile R
etai
ned
(%)
Tensile Retention ComparisonLubricant B (7 day @ 100°C) to Water-Aged (7 day @ 100°C)
85%
• Lubricant B (100°C) – 26 out of 27 specimens met 85% retention• Lubricant B (100°C) - Ave tensile retention of 96% - range 76% to 108%
0%
50%
100%
150%
200%
250%
O C X S G Q E K Z T W R P N B AA L I J A F M Y V D U H
Jacket Compound Designation
Tens
ile R
etai
ned
(%)
Elongation Retention ComparisonLubricant B (7 day @ 100°C) to Water-Aged (7 day @ 100°C)
85%
• Lubricant B (100°C) - 24 out of 27 specimens met 85% retention• Lubricant B (100°C) - Ave elongation retention of 114% - range 52% to 200%
75%
80%
85%
90%
95%
100%
105%
T N X U V C Q D Y B M E S H L O P Z I F G W A
Jacket Compound Designation
Ten
sile
Ret
aine
d (%
)
Tensile Retention ComparisonLubricant B (30 day @ 50°C) to Water-Aged (30 day @ 50°C)
85%
• Lubricant B (50°C) – 23 out of 23 specimens met 85% retention• Lubricant A (50°C) - Ave tensile retention of 97% - range 86% to 103%
0%
50%
100%
150%
200%
250%
300%
H T C Q I E F L D B Y G U Z X P V W A N S M O
Jacket Compound Designation
Ten
sile
Ret
aine
d (%
)
Elongation Retention ComparisonLubricant B (30 day @ 50°C) to Water-Aged (30 day @ 50°C)
85%
• Lubricant B (50°C) - 19 out of 23 specimens met 85% retention• Lubricant A (50°C) - Ave elongation retention of 115% - range 74% to 256%
Observations – Lubricant Aging Tests
1. Water-based pulling lubricants can affect the physical properties of the hydrate loaded jackets.
2. Not all lubricants are the same, with some lubricant formulations apparently more suitable than others.
3. Lubricant B had less effect on these jackets than lubricant A. But lubricant B did not test compatible on the jackets most affected by water.
4. When a jacket is significantly affected by heat and/or water, water-based lubricants will not test well on it, especially at the at 100°C aging tests.
5. 50°C aging, even at the longer exposure, affects physical properties less than the 100°C aging.
6. Elongation aging changes were, on the average, greater than tensile changes.
Summary
1. Today’s LSZH jackets can be affected by commercially available pulling lubricants.
2. The only known field jacket failure was associated with significant physical stress on the jacket.
3. Universal lubricant compatibility with all tested LSZH jackets has not been shown, although compatibility has been shown with the more robust jackets.
4. Specific testing (jacket and lubricant) should be done to insure compatibility.
5. Studies are continuing to define the lubricant ingredients most suitable for use on LSZH materials.