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The exposed cable insulation on the lug

side of assembled stress cone kits, which

will be operated either outdoors or in areas

subjected to contamination or moisture,

shall be overwrapped with at least one layer

70 HDT.

All splices on spacer cable operating at 5

kV and above shall be overwrapped with

Scotch 70 HDT Tape.

All splices on silicone rubber cables or

other cables which can operate at room

temperatures in excess of 30˚C/266˚F,

but not exceeding 80˚C/66˚F, shall

use Scotch 70 HDT Tape as the primary

insulating material.

5.0 Characteristics and Test Data

TypicalElectricalandPhysicalProperties

PhysicalProperties

Color

Munsell 5BG7.0/0.4 Sky Blue Gray

Thickness - Peak

ASTM-D-2148

.020 in.

Thickness - Edge

ASTM-D-2148

.008 in.

Tensile Strength

ASTM-D-412

1000 psi

Elongation at Break

ASTM-D-412

300%

ElectricalProperties

Dielectrical Strength

ASTM-D-2148

600 V/mil

Arc Resistance

ASTM-D-495

1 min. (minimum)

Fusion (Self Adhesion)

ASTM-D-2148

0.125 in.

Volume Resistivity

ASTM-D-1458

DissipationFactor

Table  shows the dissipation factor versus

temperature of 70 HDT Tape. This test was run

according to ASTM-D-50 at a stress of 50 V/mil

and a frequency of 60 cycles per second.

Dissipation Factor vs. Temperature

Scotch 70 Tape

Temperature

(˚C/˚F)

Dissipation

Factor

23/73

90/194

130/266

150/302

1.3%

1.1%

0.5%

0.7%

Table 1

DielectricConstant

Table 2 shows the dielectric constant versus

temperature of 70 HDT Tape. This test was

run according to ASTM-D-50-8 at a stress

of 50 V/mil and a frequency of 60 cycles

per second.

Dielectric Constant vs. Temperature

Scotch 70 HDT Tape

Temperature

(˚C/˚F)

Dielectric

Constant

23/73

90/194

130/266

150/302

3.0

2.9

2.6

2.5

Table 2

6.0 Performance Tests

TerminationTrackingTest

Reduced-dimension terminations are

prepared according to 3M print 2047-B-6

(Se Figure ). Each specimen consists of 8

feet of 5 kV cable and two terminations.

The contaminant employed in this test is the

formula called out in ASTM Dust and Fog

Test D-232, as shown below:

Flint (SiO

85 parts

Clay 325 mesh

9 parts

Salt (Na Cl) technical grade

3 parts

Paper, filter pulp

3 parts

all by weight

This mixture is then ball milled using 3/4

inch diameter ceramic cylinder. The milled

dust is then mixed with equal parts by

weight of water to make a slurry of paint

consistency.

Next, each termination is carefully coated in

such a manner as to deposit a uniform and

reproducible amount of contamination. The

following procedure is used:

. Mix the slurry thoroughly.

2. Submerge the inverted termination into

the slurry.

3. Withdraw the termination from the

slurry, taking care not to throw off

too much excess slurry in rotating the

termination from the inverted to an

upright position. The majority of the

excess slurry should drain off when the

termination is upright.