Page 76 - Power Cables Catalogue.pdf
P. 76
TECHNICAL INFORMATION
MAXIMUM PULLING TENSIONS
The maximum tension must not be exceeded when pulling a cable into ducts and conduits:
a. Using a pulling eye: b. Using a cable grip:
Tm = 7.16 X n X A Tg = p x k x t x (D - t)
Tm = Maximum tension, (Kg) Tg = Maximum Tension, (Kg)
n = No of conductors t = Jacket thickness, mm
A = Area of each conductor , sq. mm D = Cable overall diameter , mm
k = 0.7 Kg/sq.mm for PVC, PE & Neoprene
The tension required to pull the cable in a straight duct can be calculated as follows:
Ts = L x w x f
Ts = Tension required to pull cable, Kg.
L = Length of cable, m
w = Weight of cable, Kg/m
f = Co-ef ficient of friction
Coefficient of friction
Duct Jacket Material
Material PE PVC Neoprene
Asbestos Cement 0.56 0.56 0.68
Rigid PVC 0.34 0.52 0.53
Metal 0.36 0.55 0.60
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