Torin BIG RED T32052 Manual Del Propietário página 8

CABLE PULLING PRINCIPLES
At the Connectors
The connectors will be subjected to the cable puller's maximum pulling force.
Several types of rope connectors—clevises, swivels, and rope-to-swivel connectors—are available. Follow the
instructions provided with each to provide a good connection.
Two types of wire connectors—wire grips and pulling grips—are available. The wire grip uses a set screw to
clamp onto the conductors of the cable. The pulling grip consists of a wire mesh basket that slides over the
cable and grips the insulation.
When selecting a pulling grip, it is extremely important to select a grip of the correct (1) type, (2) size, and (3)
maximum rated capacity.
At the Sheaves
Sheaves are used to change the direction of the pull. A change in direction creates a new resultant force that
may be greater than the cable puller's maximum pulling force. This new resultant force exerts itself on the
sheaves, sheave anchoring system, and support structures illustrated.
The resultant amount of force depends on the angle of the change in direction.
Tailing the Rope
The rope must be pulled off of the capstan as the pull progresses. The rope that has left the capstan is the "tail."
The process of pulling the rope off of the capstan is called tailing the rope.
The resistance of the cable varies throughout the dura-tion of the cable pull. Changes in resistance are due
to characteristics of the rope, changes in conduit direction, and changes in the amount of friction. The "feel"
of the rope provides this information about the pull. This is called tactile feedback. Adjust the tailing force as
necessary to compensate for these changes.
Control of the Pull
Decreasing the tailing force will decrease the pulling force, until the rope slips on the capstan and the pull
stops. This provides a high level of control over the progress of the cable pull.
Do not allow the rope to slip on the capstan for more than a few moments. If it becomes necessary to
com-pletely stop a pull, shut off the puller and maintain enough tailing force to hold cable in place. Tie the rope
off to hold it in place.
Amount of Tailing Force
While the rope and cable are under tension, it is impor-tant to maintain the proper amount of tailing force.
Too little tailing force will allow the rope to slip on the capstan. This will build up excessive heat and acceler-
ate rope wear, increasing the possibility of breaking the rope.
The proper amount of tailing force will stop the rope from slipping on the capstan and produce a sufficient
amount of pulling force to pull in the rope and cable.
Too much tailing force is any amount more than is necessary to stop the rope from slipping on the capstan.
Excessive tailing force will not increase the pulling force or pulling speed.
Number of Wraps of Rope Around the Capstan
An experienced operator should choose the number times the rope is wrapped around the capstan.
The proper number of wraps allows the operator to control the progress of the pull with a comfortable amount
of effort.
Using too few wraps requires a large tailing force to accomplish the pull. Using too few wraps also makes the
rope more likely to slip on the capstan. This builds up heat and accelerates rope wear. Using too many
wraps causes the rope to grab the capstan tighter. This accelerates rope wear, wastes power, and increases
the possibility of a rope overlap. Using too many wraps also reduces tactile feedback, so you receive less
information about the pull. You cannot quickly relax the tailing force when there are too many wraps.
If the rope becomes difficult to tail, add another wrap of rope. Turn off the puller and release all of the tension
in the rope. Add a wrap and resume pulling. Be aware, however, that some pulls will require tension to hold
the cables in place. In these cases, do not attempt to release all of the tension and add a wrap of rope. You
will need to anticipate the number of wraps before start-ing the pull.
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