No modern building is functional without the labyrinth of wires and cables running through walls and above ceilings to provide basic electricity and telephone service, high-speed data and video connections, and operate sophisticated, “smart” building controls and security systems.
For residential and light commercial work, wire can be pulled manually. But power-pulling tools are needed for larger projects with long runs and multiple-cable installations.
A pulling tool’s basic components are its frame, power source, capstan that pulls rope and wire, the mechanism that turns the capstan, and pulling rope.
Cable pullers are available in several sizes offering a range of pulling capabilities, and a host of accessories are considered to be necessities.
Puller components are the same as those of the first power puller introduced by Ensley Tools in the 1960s, but product evolution makes today’s pullers more powerful and versatile, easier to use, and safer.
“Until recently, the trend was toward bigger and bigger, as manufacturers designed more powerful pullers to achieve greater productivity,” said Brian Ray, Maxis Corp.’s director of new product development. “Now, the move is toward smaller models.”
John Ireton, president of HIS Business Mfg. Co., identified two waves in the cable-puller market.
“As pullers became a necessity,” he said, “buyers wanted self-contained, multispeed equipment—one machine that could do everything. Then came individual models: small, light-duty pullers; medium-weight pullers to handle a wider range of jobs; big machines for high-voltage installations. Medium-duty units serve the bulk of today’s market.”
Ray estimated that 80 percent of cable pulls made today are for subpanels.
“Big pullers are needed for long runs,” he continued. “But for every big run to a distribution center, there may be a dozen runs to subpanels, and these can be made with small pullers. Even runs for large equipment and air conditioning often can be made with compact pullers. They are less expensive to purchase, can be set up quickly, are easy to operate, and save time and money. Every time a contractor does not have to set up a big puller, he saves money.”
Small, self-contained models can be carried by one person. For a pull, the frame is attached to the conduit. Most have two pulling speeds: fast and slow (for heavy pulls). Large pullers generally are bolted to the floor. Some models include dollies to move them around job sites, and speciality manufacturers offer carts for big pullers.
“Newer, mobile carriage-and-boom systems reduce setup time by eliminating the need to drill holes in floors to mount the puller,” said John Green, director of marketing for Greenlee Textron.
Cable-puller capabilities are defined by pulling force, stated in pounds or kilonewtons (kN); pulling speed in feet or meters per minute; and rope strength, defined by average breaking strength.
“In addition to the puller and rope, several items are considered essential for most cable pulls,” said Dick Buschel, national sales manager for the Ensley Tool Division of Rothenberger USA. “They include wire grips, rope clevises to connect grip and rope, sheaves—available in various configurations—to support cable and keep it in alignment during the pull, wire carts to hold supplies of wire, and reel jacks to control payout of cable off spools. Mandrels are run through conduit before a pull to ensure there are no obstructions in conduit.”
Lubricants are important
“Pulling lubricant is very important to reduce friction and minimize damage to the cable jacket,” said Dave Wieseman, product manager at Gardner Bender. “A high-quality lubricant decreases pulling time and labor necessary to complete the job. Conditions dictate the type of lube, but except in cold weather, a cream-style lubricant is most common.”
To match cable puller and accessories to job requirements, contractors consider length of the pull, number of bends in the conduit, cable weight, and the amount of force necessary to complete the pull. It is necessary to know these variables to select the correct pulling rope.
Safety is an important consideration when evaluating pullers.
“Look for safety features such as a right-angle sheave to get the operator out of the danger zone when pulling,” said Green. “Some models have a capstan that has a rope ramp to prevent rope overlap. It also is important to have some sort of force-limiting device built into the puller. Consider how these features make a pull more productive and help prevent accidents.”
Power pullers are available today with pulling capacities ranging from 1,000 to 8,000 pounds. One of the most significant advances found in today’s pullers is a change from chain drives to planetary and worm-drive systems that allow equipment to generate high puller forces in smaller packages. Built-in meters monitor pulling force. Some small- and medium-size models use power drills to drive the capstan. There are many anchoring options, and right-angle sheaves allow operators to position themselves to avoid injury should the rope break during a pull. And manufacturers think the evolution of cable-pulling equipment will continue.
“In the future, pullers will be more portable, easier to set up, and will have more power for their weight,” said Buschel. “The increasing amount of data communications being installed requires equipment that accommodates VDV cables.”
“There is more fiber optic cable today, and you need better load-control when pulling it,” said Ray. “For fiber, it is critical to be able to measure pulling force, and it’s better to incorporate that into the pulling machine than using a separate device.”
“There definitely are more light-duty pullers on the market today,” said Wieseman, “and in the future, pullers will be more compact, more portable and easier to set up.”
Green said that cable runs are becoming longer and cable is larger, ensuring a continuing need for big, powerful pullers. EC
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at 405.748.5256 or email@example.com.
Greenlee Cable Pulling Tips
Cable pulling is a complex job. These tips for selecting and using pulling equipment and accessories are summarized from information provided by John Green, Greenlee Textron director of marketing:
Puller selection. Use the smallest puller capable of completing the job. Smaller units pull faster than large-capacity units, which can greatly affect how fast pulling jobs are completed.
Mount the puller effectively. Mounting the puller correctly is essential. If the puller is bolted to the floor, it is best to use a mounting bracket that allows the anchors to be tightened completely into the concrete with the puller attached to the bracket. The anchor must be able to withstand the forces the puller will exert during operation.
Match components based on puller capacity. Like a chain, a pulling system is only as strong as its weakest link. Use components that are rated to work together. Wire, grips, sheaves and sheave mountings must be matched to puller capacity.
Use quality stands to support reels. Quality stands and spindles work together to help reduce setup time, minimize pulling problems from unruly reels and lessen the risk of back injury. Home-built jack stands made with conduit often cannot support the weight of reels and sag under their weight, affecting pulling.
Consider a cable feeder. Relatively new to the market, these units help gather and bundle the wire as it feeds into the conduit. As a result, only two workers are needed to feed cable—one to apply lubricant, the other to control the feeder.
Position stands for even feeding. Reels feed best when they are set in line. If space prohibits that, stagger the reels in a double configuration or minimize the angle at which the cable feeds from reels to the conduit.
Select the right rope.
Use rope correctly. When operating the capstan, start with only two or three wraps around the capstan and increase if the rope starts to slip. Beginning with too many turns reduces control. As the pull progresses, stand behind the accumulating pile of rope, and never wrap rope around wrist, waist or feet.
Communicate. The puller operator often cannot see workers feeding cable, but two-way radios keep crew members in touch.