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are
for
new,
single-conductor
wire
and
cable
after
being
sub:
jected
to
an
a-c
high
voltage
test
and
based
on
a
d-c
test
poten-
tial
of
500
volts
applied
for
one
minute
at
a
temperature
of
60°F.
These
standard
minimum
values
(for
single-conductor
cable)
are
based
on
the
following
formula:
RoR
los
d
where
R=megohms
per
1000
feet
of
cable
K=constant
for
insulating
material
D=outside
diameter
of
conductor
insulation
d=—diameter
of
conductor
Minimum
values
of
K
at
60°F.
Insulation
Type
Impregnated
Paper..........
T
ET
2640
Varnished
Cambric..........
ο
--ὺ-
2640
Thermoplastic—Polyethylene
.............
above
50,000
Composite
Polyethylene
ఎ.
30,000
Thermoplastic-Polyviny]
:
Polyvinyl
ΟΠ]οπάεθ050.......
'...ῳα.,.
500
-Polyvinyl
Chloride
75°C.
.
....
.
(2
aes
ΙΙ.
2,000
Grade
Natural
Rubber
Synthetic
Rubber
Gode
s
s
ee eo
oe
es
aig
ois
eas
nn
E
950
ΡοΤΙΟΤΠΠΑΠΟΟ
ον...
10,560
....
o.oo
ac
2000
Neat
[65190216
లలు.
100560...
2000
Ozone
[6516
10,000
ΡΟ.
2000
ον
μον
ο
A
4,000
D
See
pages
48
and
49
for
tables
of
logy
న్󰾭
The
insulation
resistance
of
one
conductor
of
a
multiconduc-
tor
cable
to
all
others
and
sheath
is:
RER
log
-
where
q
D=diameter
over
insulation
of
equivalent
single
conductor
cable
—d42c+2b
d=diameter
of
cond.
(for
sector
cables
d
equals
diameter
of
round
cond.
of
same
cross-section)
c=thickness
of
conductor
insulation
b=thickness
of
jacket
insulation
(all
dimensions
must
be
expressed
in
same
units)
.
[46
]