#Cable pulls software#
#Cable pulls code#

If the cables can be accessed in the middle of the run somewhere, properly set-up assist tuggers can also break up the run. Pull Boxes / Assist Tuggers – Add pull boxes to break the pull up into sections (pull out through the manhole and refeed back in). Southwire uses 0.15 for their no lube building wire products in PVC conduit. For a new installation with a good lubrication plan and experienced installation crew, 0.25 could be a more aggressive number. 0.35 is a common COF number for most common PVC jacketed industrial cables or regular building wire pulled through existing conduits. Tighter Coefficient of Friction (COF) Assumption – This parameter makes a huge difference in the final numbers. That big 24” OD sheave is probably too small! You should ensure that the cable minimum bend radius limitations are respected. Reduce run lengths – This reduces pulling tensions.īigger Conduit Sweeps and Sheaves – This makes a big difference to the SWBP. Straighten Out the Run – The fewer bends, the better. However, using a cable feeder to push the cable in access points can help.Īdvance Planning & Field Communication – Can the field handle the reel you are specifying? Can it be placed where your pull calculation starts? Is there room to lay down cable for hand pulls or refeeds? Incoming Tension Assumption – Don’t sweat +/- 25 lbs on incoming tension assumptions as that will be a rounding figure in the final pull.

#Cable pulls code#

Upsizing the Conduit – Although you must maintain code required maximum fill requirements, upsizing conduits doesn’t lower tensions or SWBP by much.

Maximum Pulling Tension – For power cables, this is usually not a limitation as the basket grip or pulling equipment usually limit pulling tensions before the conductors. Excessive SWBP, usually visible in flattened armour or stretched jackets, can result in insulation damage which decreases cable life.Ĭommon misconceptions that have only minor effects on the resulting pull calculations: Side wall bearing pressure (SWBP), the radial force imposed at the bends, is by far the most common limiting factor. Pull calcs are more an art than a science as the calculations involve a lot of big assumptions making many other parameter assumptions rounding figures. Performing more pull calcs and comparing them to real site experiences will result in an improved ability to make accurate assumptions. These parameters include gauge size, the number of conductors, cable OD and weight, raceway type and size, and each pull segment. The process involves inputting a few cable and pull set up parameters to verify that pulling forces will not result in cable damage. Calculators are also available in most electrical modelling software. Personally, I like Southwire’s Cable Pull Calculator, but a quick search will result in several other on-line options.

#Cable pulls software#

While hand calculations can quickly spiral in complexity, there is software available to help simplify the process. It can result in partial discharge, leading to premature failures, commonly after 5 or 6 years of use. Medium Voltage cables are especially susceptible to this kind of damage. The type of damage commonly created by excessive pulling forces will typically pass DC HiPot or VLF acceptance testing. Pull calcs are relatively easy to do but surprisingly few engineers or contractors use them. Doing this early in the project allows for cable sizing and routing options that are often not available late in the game. It’s good design practice to perform a cable pull calculation for cable pulling and cable laying runs that might be difficult. Choose three or four exercises that cover your key lower body muscles – quads glutes, hamstrings, and calves – and perform a total of 16 sets, with reps ranging between a heavy six and a light thirty.Image | Allteck Line Contractors Inc | Empowering Lives, Connecting Communities Cable Pulling Large Cables Calculations The 13 cables leg exercises provided here provide you with all you need to work your legs to the max for years to come. Cables also allow you to perform squat-like exercises without putting compressive pressure on your spine.

The varied angles of resistance are ideal to provide enhanced targeted stress on the working muscle. Working your legs with cables allows you to work your leg muscles through their ideal biomechanical range of motion.

Staring with your knees slight bent and your lower back neutral, thrust your hips forward to drive your arms up.

Grab the rope handle in both hands between your legs.

Stand in front of the machine, facing away from it.

Set the pulley to knee level and attach a rope handle.

Squeeze the glutes tightly as your drive your hips forward. Single cable pulley machine, rope handle attachment Training Tips