Information on Electrical Conduit Bending

Bending conduit can save time and money when installing electrical lines.

Installing electrical wiring will often involve using conduit to protect and direct the wiring. Conduit can be either plastic or metal and comes in several sizes to accommodate different electrical wire and cable sizes. (Wire is a single transmission line. Cable is a bundle of two or more wires.)

Configuring conduit to certain routes involves using angled fittings or bending. More often the conduit is bent because 90-degree right angle fittings are difficult for thick cabling to follow. A wider-radius bend allows cable to smoothly snake through the conduit for installation.

Bending

Bending conduit involves more than grabbing each end and pulling the ends together. Bending involves working the conduit around a radius so it will bend evenly without crimping or cracking. Since the inside of the round conduit follows a shorter bend than the outside, the inside will want to wrinkle and the outside will want to collapse and crimp. Working the conduit around the bend to prevent this from happening keeps the interior opening round and clear of any obstruction.

Fittings

A decision must be made when installing conduit whether to bend the conduit around a curve or install an angled fitting. Fitting makes quick work of running conduit but can lead to angles that stiff heavy cable will not easily slide through. A "radiused bend" offers an easier path for the electrical line.

Also, fittings add to the cost of the conduit. A length of conduit that is bent costs the same per foot whether it is straight or bent. Fittings add additional cost at every turn. If a large amount of conduit is installed over great distance, the cost of the fitting added to the job can be prohibitive.

Tools

There are different bending tools to shape and curve conduits into bends. Hand tools can bend light conduit up to about 1/2-inch in diameter. Heat tools can shape plastic conduit without damaging and possibly thinning the material. Larger tubing and pipe benders can shape conduit in diameters up to 8 inches with accurate bends. These tools also eliminate any problem with crimping and cracking.

Slight Bends

Electrical conduit is a light thin-walled tube not meant to handle pressure or caustic media. It simply protects electrical lines. If the need arises to make a slight bend (less than 10 degrees) the conduit can be shaped just by attaching the fasteners and gently forcing the tubing around the slight curve. No need to break out the tools and fittings just to slightly nudge the conduit around an obstacle. Over time the metal or plastic will relax and retain the slight bent shape.

Installing Electrical Line

Whether bent or straight, remember to run the line through the conduit as it is assembled. Try to avoid completing a bent conduit with several turns and then attempting to run the line. This can lead to a near impossible jam in the conduit and require disassembly to get the line through from end to end.

References

• Dulley: How to Install Outdoor Wiring
• Allied Tube: Conduit Guide