1. Pulling Grips:
The pulling grips are used to attach the pulling line to the cable to be pulled to the raceway. There are two basic types of traction grips that are frequently used for cable installations: basket grips and pulling eyes.
A basket grip is a flexible metal device that slides over the end of the conductor to be pulled. The handle of the basket has a web-like grip that is tightened when tension is applied to the traction line. Long basket grips should be used to pull type MC cables.
To use the basket grip, the frame is removed for a short distance, the tape is applied over the frame and over the conductors, and the basket clamp is placed over the rope to allow the grip to tighten both the frame and the drivers.
To prevent the cable from twisting during the traction operation, a pivot was installed in the traction line where it joins the grip of the basket.
There must be sufficient clearance at the traction end so that the last 600 mm (2 feet) of cable can be removed beyond the grip of the basket before the cable is spliced or terminated.
Pull eyes are sometimes used to pull larger sizes and long sections of cable. A traction eye is a steel eye that is usually attached directly to the cable conductors. Once the extraction operation is complete, the pulling eye should be removed from the cable.
A swivel is used to connect the pulling line to the traction eye to prevent the cable from twisting during the traction operation.
A pull line is used to pull the cable through the conduit or cable tray during cable installation. The traction lines can be made of cable or rope and are provided in various sizes.
The type of traction line used for a particular installation depends on the size of the conductor to be pulled, the type of traction grip to be used and the length of the traction.
Once the pulling line is completely stretched across the affected raceway, the pulling line is firmly attached to the tpilling grip and to the traction device through a roller. The roller is connected to a dynamometer to allow tension in the traction line to be evaluated along the traction.
To reduce friction during the pulling operation, the lubrication must be applied generously and continuously to the conduit. Increased friction during pulling can also increase the tensile stress that is applied to a cable during its installation.