TEST METHOD FOR ESTABLISHING VOLUME RESISTIVITY
COMPATIBILITY OF WATER BLOCKING COMPONENTS
WITH EXTRUDED SEMICONDUCTING SHIELD MATERIALS
PUBLICATION ICEA T-32-645-2012
October 10, 2012
© 2012 by
INSULATED CABLE ENGINEERS ASSOCIATION, Inc.
Insulated Cable Engineers Assoc., Publication No. T-32-645-Revised 2012
TEST METHOD FOR ESTABLISHING VOLUME RESISTIVITY
COMPATIBILITY OF WATER BLOCKING COMPONENTS
WITH EXTRUDED SEMICONDUCTING SHIELD MATERIALS
Published by
Insulated Cable Engineers Association
P.O. Box 1568
Carrollton, Georgia 30112
www.icea.net
© Copyright 2012 by the Insulated Cable Engineers Association. All rights including translation into other
languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection
of Literary and Artistic Works, and the International and Pan American Copyright Conventions.
NOTICE AND DISCLAIMER
The information in this publication was considered technically sound by the consensus of persons
engaged in the development and approval of the document at the time it was developed. Consensus does
not necessarily mean that there is unanimous agreement among every person participating in the
development of this document.
The Insulated Cable Engineers Association, Inc. (ICEA) standards and guideline publications, of which the
document contained herein is one, are developed through a voluntary consensus standards development
process. This process brings together persons who have an interest in the topic covered by this
publication. While ICEA administers the process and establishes rules to promote fairness in the
development of consensus, it does not independently test, evaluate, or verify the accuracy or
completeness of any information or the soundness of any judgements contained in its standards and
guideline publications.
ICEA disclaims liability for personal injury, property, or other damages of any nature whatsoever, whether
special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use
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expressed or implied, as to the accuracy or completeness of any information published herein, and
disclaims and makes no warranty that the information in this document will fulfill any of your particular
purposes or needs. ICEA does not undertake to guarantee the performance of any individual
manufacturer or seller’s products or services by virtue of this standard or guide.
In publishing and making this document available, ICEA is not undertaking to render professional or other
services for or on behalf of any person or entity, nor is ICEA undertaking to perform any duty owed by any
person or entity to someone else. Anyone using this document should rely on his or her own independent
judgement or, as appropriate, seek the advice of a competent professional in determining the exercise of
reasonable care in any given circumstances. Information and other standards on the topic covered by this
publication may be available from other sources, which the user may wish to consult for additional views
or information not covered by this publication.
ICEA has no power, nor does it undertake to police or enforce compliance with the contents of this
document. ICEA does not certify, test, or inspect products, designs, or installations for safety or health
purposes. Any certification or other statement of compliance with any health or safety-related information
in this document shall not be attributable to ICEA and is solely the responsibility of the certifier or maker of
the statement.
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page i
Contents
Page
FORWARD
.............................................................................................................................................ii
Section 1 GENERAL ..................................................................................................................................... 1
1.1 SCOPE ................................................................................................................................ 1
1.2 GENERAL INFORMATION ................................................................................................. 1
1.3 DEFINITIONS ..................................................................................................................... 1
Section 2 TEST SPECIMENS ....................................................................................................................... 2
2.1 SPECIMEN PREPARATION ............................................................................................... 2
2.2 MEASUREMENT ELECTRODES ....................................................................................... 2
Section 3 TEST EQUIPMENT ....................................................................................................................... 3
3.1 MEASURING INSTRUMENT .............................................................................................. 3
3.2 OVEN .................................................................................................................................. 3
3.3 TEMPERATURE RECORDER ........................................................................................... 3
Section 4 COMPATIBILITY EVALUATION ................................................................................................... 4
4.1 COMPATIBILITY TEST PROCEDURE............................................................................... 4
4.2 PERFORMANCE EVALUATION ........................................................................................ 4
4.2.1 Volume Resistivity.......................................................................................................... 4
4.2.2 Volume Resistivity Stability ............................................................................................ 4
Section 5 APPENDICIES .............................................................................................................................. 7
APPENDIX A SPECIMEN PREPARATION PROCEDURE FOR PUMPABLE CONDUCTOR
FILLING COMPOUNDS AND WATER SWELLABLE POWDERS ........................................... 7
APPENDIX B SPECIMEN PREPARATION PROCEDURE FOR EXTRUDABLE
CONDUCTOR FILLER COMPOUNDS, WATER SWELLABLE TAPES, OR WATER
SWELLABLE YARNS .............................................................................................................. 10
APPENDIX C VOLUME RESISTIVITY .................................................................................... 12
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page ii
Foreword
This test method for establishing volume resistivity compatibility of water blocking components with
extruded semiconducting shield materials, T-32-645, was developed by the Insulated Cable Engineers
Association, Inc (ICEA).
ICEA publications are adopted in the public interest and are designed to eliminate misunderstanding
between the manufacturer and the user and to assist the user in selecting and obtaining proper product
for his particular need. Existence of an ICEA publication does not in any respect preclude the
manufacture or use of products not conforming to the publication. The user of this publication is
cautioned to observe any health or safety regulations and rules relative to the manufacture and use of
cable made in conformity with this publication.
Requests for interpretation of this publication must be submitted in writing to the Insulated Cable
Engineers Association, Inc. P.O. Box 1568, Carrollton, Georgia 30112. An official written interpretation will
be provided. Suggestions for improvements gained in the use of this publication will be welcomed by the
Association.
The members of the ICEA working group contributing to the revision of this publication consisted of the
following:
P.M. Leblanc – Chairman
F. Clark
H. Soleski
C. Lindler
R. Szilagyi
R. Williamson
C. Spradlin
E. Bartolucci
J. Cancelosi
F. Kuchta
R. Thrash
W. Temple
K. Nuckles
R. Bristol
R. Fleming
D. Farrick
E. Walcott
B. Crawford
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 1
Section 1
GENERAL
1.1
SCOPE
This test method provides procedures for establishing volume resistivity compatibility of water blocking
components with extruded semiconducting shields utilized in MV, HV or EHV power cables. The
compatibility test is designed to verify that the electrical properties of a semiconducting material used as a
conductor or insulation shield are not adversely affected when exposed to a water blocking component.
These water blocking components can be incorporated in a conductor, over a conductor, over an
insulation shield, or around a metallic shield or concentric neutral. It describes a test method of
demonstrating that the volume resistivity and volume resistivity stability remain within their specified limits
when a semiconducting material is exposed to a water blocking component at the emergency operating
temperature of the cable.
1.2
GENERAL INFORMATION
Units in this Standard are expressed in the English system.
approximate metric equivalents are included.
1.3
For information purposes only, their
DEFINITIONS
Water Blocking Component: A non-metallic material incorporated in a cable construction intended as an
impediment to water penetration. A water blocking component can be a pumpable or extrudable
conductor filler compound, a water swellable tape, yarn, or powder, or a combination thereof.
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 2
Section 2
TEST SPECIMENS
2.1
SPECIMEN PREPARATION
The combination of water blocking component and semiconducting shield material are to be prepared as
per the appropriate Specimen Preparation Procedure provided in Appendices A and B.
Appendix A:
 pumpable conductor filler compounds with conductor shield materials;
 water swellable powders with conductor and insulation shield materials;
Appendix B:
 extrudable conductor filler compounds with conductor shield materials;
 water swellable tapes with conductor and insulation shield materials; and
 water swellable yarns with conductor and insulation shield materials.
Alternate methods of specimen preparation may be permitted provided the final test specimens fully
comply with paragraph 2.2 and that Appendices A and B, as applicable, would serve as a referee method.
2.2
MEASUREMENT ELECTRODES
Two silver-painted electrodes shall be applied to each side of the semiconducting shield material
specimen. The two potential electrodes (inner) shall be at least 2 inches (50.8 mm) apart and shall be
0.125 inch (3.18 mm) minimum width. A current electrode shall be placed at least 1 inch (25.4 mm)
beyond each potential electrode. When a high degree of accuracy is not required, this test may be made
with only two electrodes spaced at least 2 inches (50.8 mm) apart.
After the paint has been allowed to dry for at least one hour at room temperature, copper wires are applied
around each silver paint band and twisted to form a tail. Silver paint may be applied to the copper wire to
help ensure intimate contact with the electrodes. These copper wires shall be extended to allow resistance
measurements of the specimens while at the emergency operating test temperature in an oven.
The final test specimens shall be as shown in Figures 1 or 2 based upon the number of electrodes used.
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 3
Section 3
TEST EQUIPMENT
3.1
MEASURING INSTRUMENT
A suitable instrument (e.g., Wheatstone Kelvin Bridge or Ohmmeter) or instruments (e.g., voltmeter and
ammeter) shall be utilized for determining resistance and provide a source of 60 Hz ac or dc voltage. The
energy released in the conducting component shall not exceed 100 milliwatts.
3.2
OVEN
A convection type, forced draft, circulating air oven, shall be utilized capable of maintaining any constant
(± 3°C) temperature up to 140°C, e.g., Hot Pack Model 1204—14, Blue M Model OV-490, Precision Type
A.
3.3
TEMPERATURE RECORDER
A suitable recorder shall be utilized for measuring oven temperature continuously.
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 4
Section 4
COMPATIBILITY EVALUATION
4.1
COMPATIBILITY TEST PROCEDURE
Five specimens shall be subjected to the stability of volume resistivity test per ICEA Publication T-25-425,
“Guide for Establishing Stability of Volume Resistivity for Conducting Polymeric Components of Power
Cables.”
When testing water blocking components prepared in accordance with Appendix B (extrudable strand
filling compounds, water swellable tapes, or water swellable yarns), in order to maintain good contact with
the semiconducting shield material during oven aging, a nominal 1400 gram metal plate may be placed on
top of each set of five specimens. Polyester sheets shall be used to isolate the specimens electrically from
the plate and facilitate resistance measurements.
At the conclusion of the stability test, all five specimens are removed from the oven and allowed to cool at
room temperature. An attempt to remove as much as possible of the water blocking component shall be
made without any damage to the semiconducting shield material specimens.
For the four-electrode method, connect the two outer electrodes (current) in series with the current source
and an ammeter, or the current leads of a bridge. Connect the two inner electrodes (potential) to
potentiometer leads of a bridge, or to a voltmeter. A dc or 60 Hz ac source can be used. For the twoelectrode method, connect the electrodes to an ohmmeter.
The resistance of the conducting component between the electrodes shall be measured and the volume
resistivity is computed as defined in Appendix C, and recorded.
4.2
PERFORMANCE EVALUATION
The combination of the water blocking component and the semiconducting shield material is found
compatible upon satisfying the requirements of 4.2.1 and 4.2.2.
4.2.1
Volume Resistivity
The volume resistivity of each specimen shall not exceed the maximum value allowed by the applicable
ICEA Standard for the conductor shield or insulation shield material.
4.2.2
Volume Resistivity Stability
Stability of volume resistivity of each specimen shall be demonstrated as defined and computed per ICEA
Publication T-25-425.
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 5
FIGURE 1
TYPICAL TEST SPECIMEN PREPARATION
TWO ELECTRODE METHOD
0.25"
WATER BLOCKING
COMPONENT
1.5”
2"
5"
T1
T3
ELECTRODES
TWISTED WIRE LEADS
T2
SEMICONDUCTING
SHIELD MATERIAL
Where:
T1 = Water Blocking Component to be minimum 0.010" thick
or single layer, as applicable
T2 = Semiconducting shield material to be 0.050" thick
T3 = Band of Silver Conductive Paint to be 0.125" wide
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 6
FIGURE 2
TYPICAL TEST SPECIMEN PREPARATION
FOUR ELECTRODE METHOD (OPTIONAL)
0.25"
WATER BLOCKING
COMPONENT
1.5"
2"
5"
T1
T3
ELECTRODES
TWISTED WIRE LEADS
1"
T2
SEMICONDUCTING
SHIELD MATERIAL
Where:
T1 = Water Blocking Component to be minimum 0.010" thick
or single layer, as applicable
T2 = Semiconducting shield material to be 0.050" thick
T3 = Band of Silver Conductive Paint to be 0.125" wide
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 7
Section 5
APPENDICIES
APPENDIX A
SPECIMEN PREPARATION PROCEDURE FOR PUMPABLE CONDUCTOR FILLING
COMPOUNDS AND WATER SWELLABLE POWDERS (NORMATIVE)
1. Mold a 4-inch (10.16 cm) by 5-inch (12.70 cm) nominal 50-mil (1.27 mm) thick slab from the
semiconducting shield material. Thickness tolerance ± 5 mils (±0.13 mm).
2. Prepare a template to the same external dimensions of the molded plaque and with a thickness of
minimum 10-mils (0.25 mm). A window shall be cut out from the center of the template with internal
dimensions of 2.5-inches (6.35 cm) wide by 1.5-inches (3.81 cm) long.
3. The template is to be placed centered over the molded plaque as shown in Figure A-1 and tightly
secured.
4. Obtain a sufficient quantity of conductor filling compound or water swellable powder and place it into the
window on the template as shown in Figure A-2. The quantity must be sufficient to completely fill the
window after pressing as shown in Figure A-3. Water swellable powder may be wetted to assist in
adhesion to the plaque of semiconducting shield material.
5. Position a sheet of 5-mil (0.13 mm) thick polyester film 4-inch (10.16 cm) by 6-inch (15.24 cm) over the
template.
6. Position the slab between 5-mil (0.13 mm) thick polyester film separator sheets, approximately 8-inch
(20.32 cm) by 8-inch (20.32 cm). These sheets will prevent excess water blocking component from
contaminating the press platens.
7. Place two steel shims of suitable thickness on the lower plate as shown in Figure A-3 so that the final
thickness of the water blocking component, measured after the specimen is removed from the press and
cooled to room temperature, is a minimum 10-mils. The press is slowly closed and held for approximately
30 seconds before unloading. For pumpable conductor filling compound, the plates may be heated as
necessary to facilitate spreading of the filler during compression.
8. Remove the two 8-inch (20.32 cm) by 8-inch (20.32 cm) polyester film separator sheets applied in Step
6.
9. The polyester film applied over the template in Step 5 will remain in contact with the water blocking
component throughout the test. However, the excess polyester is to be trimmed prior to cutting the test
specimens from the plaque to facilitate further preparation of each test specimen.
10. Die cut the plaque to obtain 5 test specimens 0.250-inches (6.35 mm) wide by 5-inches (12.70 cm)
long with each specimen containing a minimum 10-mils thick water blocking component centered 1.5inches (3.81 cm) long on the test specimen as shown in Figure A-4. As an alternate the plaques may be
cut with a razor knife and in both cases the plaques may be cooled to a minimum of 0°C for 15 minutes to
facilitate cutting.
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 8
4”
WINDOW
1
1/2”
5”
2 1/2”
FIGURE A-1
5 MIL
POLYESTER
TAPE
4”
6”
FIGURE A-2
WATER BLOCKING
COMPONENT
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 9
WATER BLOCKING
COMPONENT
4” X 6”
POLYESTER
UPPER PLATEN
SHIM
MOLDED PLAQUE
TEMPLATE
LOWER PLATEN
SHIM
8” X 8” POLYESTER
FILM SHEETS
FIGURE A-3
1 1/2”
0.010” MINIMUM
0.050”
0.25”
5”
TEST SPECIMEN
FIGURE A-4
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 10
APPENDIX B
SPECIMEN PREPARATION PROCEDURE FOR
EXTRUDABLE CONDUCTOR FILLER COMPOUNDS,
WATER SWELLABLE TAPES, OR WATER SWELLABLE YARNS (NORMATIVE)
1. Mold a 2.5-inch (6.35 cm) by 5-inch (12.70 cm) nominal 50-mil (1.27 mm) thick slab from the
semiconducting shield material. Thickness tolerance ± 5 mils (±0.13 mm).
2. For conductor filling compounds, mold a 2.5-inch (6.35 cm) by 1.5-inch (3.81 cm) minimum 10-mil (0.25
mm) thick slab with a thickness tolerance ± 2 mils (±0.05 mm)..
3. For water swellable tapes, obtain a 2.5-inch (6.35 cm) by 1.5-inch (3.81 cm) section.
4. For water swellable yarns, obtain enough yarn to completely cover the 2.5-inch (6.35 cm) by 1.5-inch
(3.81 cm) section.
5. Position the plaque of conductor filling compound, water swellable tape, or water swellable yarns
centered over the molded plaque of semiconducting shield material as shown in Figure B-1. Water
swellable tapes or yarns may be wetted to assist in adhesion to the plaque of semiconducting shield
material.
6. Die cut the plaque to obtain 5 test specimens 0.250-inches (6.35 mm) wide by 5-inches (12.70 cm) long
with each specimen containing the water blocking component centered 1.5-inches (3.81 cm) long on the
test specimen as shown in Figure B-2. As an alternate the plaques may be cut with a razor knife.
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 11
WATER
BLOCKING
COMPONENT
SEMICONDUCTING
SHIELD MATERIAL
1
1/2”
5”
2 1/2”
FIGURE B-1
1 1/2”
0.010” MINIMUM OR SINGLE
THICKNESS OF WATER
SWELLABLE YARN OR TAPE
0.050”
0.25”
5”
TEST SPECIMEN
FIGURE B-2
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.
ICEA T-32-645-2012
Page 12
APPENDIX C
VOLUME RESISTIVITY (NORMATIVE)
The Volume resistivity is calculated as follows:
P = R * (t * w)
K*L
Where:
P = volume resistivity in ohm-meters;
R = measured resistance in ohms;
t = average thickness;
w = average width;
L = distance between electrodes;
K = a constant dependent on the dimensions used;
K = 39.37 for thickness, width and distance all in inches; or
K = 1000 for thickness, width and distance all in millimeters.
© Copyright 2012 by the Insulated Cable Engineers Association, Incorporated.