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TECHNICAL DATA
TECHNICAL DATA
BENDING RADII AND PULLING TENSIONS:
MINIMUM BENDING RADII:
Power Cables 600 Volts, without Sheath, Shielding or Armor:
The minimum bending radii for single and multi-conductor cables
rated 600 volts and less, and without sheath, shielding or armor
Thickness or
Min. Bending Radius as a Multiple
Conductor of
Cable
Diameter
Insulation in
Overall Diameter of Cable in Inches
Mils
1.000 and less
1.001 - 2.000 2.001
and over
169 and less
4
5
6
170 - 310 5
6
7
311 and over
--
7
8
Power Cables Over 600 volts, without Sheath, Shielding or
Armor:
1. The minimum bending radius for all cables is eight times the
overall cable diameter.
Shielded Cables without Armor, All Voltages:
1. The minimum bending radius for single conductor cable and
multi-conductor cable with an overall shield is twelve times the
overall cable diameter.
2. The minimum bending radius for multi-conductor or multiplexed
cables having individually shielded conductors is twelve times the
diameter of one of the individual conductors or seven times the
overall diameter, whichever is greater.
3. The minimum bending radius for lead sheathed cables is twelve
times the overall cable diameter.
Interlocked Armored Cable, All Voltages:
1. The minimum bending radius for cables with non-shielded
conductors is seven times the armor overall diameter.
2. The minimum bending radius for cables with shielded conductors
is twelve times the diameter of one phase conductor or seven times
the overall diameter, whichever is greater.
Note: The minimum bending radius applies to the inner surface of
the cable not the cable axis.
PULLING TENSIONS:
A. Maximum Pulling Tension on Cable
(1) With pulling eye attached to copper conductors, the
maximum pulling tension in pounds should not
exceed 0.008 times cir-mil area
(2) With pulling eye attached to aluminum conductors, the
maximum pulling tension in pounds should not
exceed 0.006 times cir-mil area
TM= 0.008 x n x CM where: TM = max.
tension, lb. n = number of conductors
CM = cir-mil area of each copper conductor
(3) With cable grip over lead sheath, the maximum pulling
tension in pounds should not exceed 1500 lb/sq. inch of lead sheath
cross-sectional area for commercial lead TM = 4712 t (D - t) where
t = sheath thickness, inches
D= overall diameter of cable, inches
(4) With cable grip over non-lead cable, the maximum
pulling tension should not exceed 1000 lb and may
not exceed the maximum tension based on 0.008 or 0.006
x total conductor area.
(5) When more than three conductors are pulled
together, the maximum pulling tension should be
reduced 20%
B. Maximum Permissible Pulling Length
L
M
=
Tm
fW
where
L
M
= pulling length, feet (straight section)
T
M
= maximum tension, lb.
W = weight of cable per foot, lb.
f = coefficient of friction (usually 0.5)
C. Pulling Tension Requirements in Ducts or Conduits
(1) For straight sections, the pulling tension in pounds equals the
length of duct or conduit multiplied by the weight per foot
of cable and the coefficient of friction (paragraph B)
T =
L
W
f
(2) For curved sections, the following formula applies:
Tc = T1 e
where
Tc = tension exiting curved section, lb
T1 = tension entering curved section, lb
a = angle of bend in radians (1 radian = 57.3 deg.)
f
= coefficient of friction (usually 0.5)
e
= naperian logarithm base
(3) To limit the sidewall bearing pressure on cables at bends, the
maximum pulling tension in pounds shall not exceed the
following factor times the radius of curvature of bend
expressed in feet:
Cable Type
Factor
Low Voltage 16 - 10 AWG
300
Low Voltage 8 AWG and LGR
500
5kV NonShielded
500
5kV - 35kV
500
Interlocked Armor (all voltages)
300
Little Rock
1-800-945-5542

Houston
1-888-388-6280

Baton Rouge

1-888-754-5707
http://www.
prioritywire
.com