Let's say you selected the correct rope for the cable pull. Your electrical distributor told you that a ¾-in. cable-pulling rope can handle 12.6 lb per 100 ft of pull and a 5/8-in. rope can handle 9.3 lb. Your calculations showed this pull would require about 9 lb, so you went with the larger rope just to add a safety factor.
To avoid shoulder strain, this pull was set up with a motorized take-up reel. The pull was going just fine, with the cable feeding smoothly into the raceway. Inexplicably, however, the cable suddenly slowed, and then the rope snapped.
Or was it inexplicable? This kind of scenario tends to occur when the cable spools and reels are taken for granted.
One solution to this kind of problem is a type of packaging that hit the market at the start of this millennium. It doesn't use cables or spools. While the initial impetus for it was reducing jobsite waste, packaging design tweaks eliminated the kinking, crossover, and tangling that can occur with spooling. For many applications, this packaging can replace the spools and reels. As the wire becomes heavier due to conductor size and/or length, this packaging becomes less attractive than the spooled wire option. In Part 7, we'll look at other solutions.