You probably bend metallic raceway all the time. But are you doing it properly? Or are you inadvertently doing things that way reduce the quality of the installation? Maybe even damaging conductors?
The following six-step method for bending metallic raceway will help you get a high quality installation every time.
Step 1. Deburr. Use a conduit reamer to remove burrs from the end of the stick of conduit or EMT. If you’re in a pinch, you can use a knife (but you’ll probably destroy its edge, making it unsafe). Screwdrivers don’t work well for this kind of thing; they tend to just bend burrs over, leaving an edge that can still slice fingers and conductors.
Step 2. Mark the distance. Where does the bend need to start? Measure to this point from the starting end of the raceway. For example, if you need a 90 at six feet from the point where the raceway exits the box, then allow for the amount of raceway entering the box fitting and mark six feet from there.
Step 3. Mark the middle. Your bender shoe should have markings indicating the distance to the middle of the bend. On the raceway, make a new mark that distance back from the mark you made previously. What if there is no marking? The number is radius of the shoe you’re using in your bender; it’s half the distance across the shoe.
Step 4. Hold the raceway up where you intend to install it. See if the “change of direction” and “middle of the bend” marks line up with where the raceway will change direction and bend.
Step 5. A trick proofreaders use is to read the text in the opposite of the normal direction. This way, they aren’t simply redoing what they already did and thus missing something they missed the first time.
You can check your raceway markings, using the same trick. Set the raceway on the floor, with the “start” end against the wall. Measure from the wall to the “bend” number marking you made in step 3. If this measurement matches the number, you’re ready for the last step.
Step 6. If you’re using an electric conduit bender, line the raceway up in the shoe and complete the bend.
If you’re using a manual bender (“hickey”), set the raceway on the floor with the “start” end firmly against a column or wall. Slip the hickey over the other end. Line up the racway “bend” mark with the hickey’s “bend” mark. While bracing the raceway against the wall, smoothly pull on the hickey handle until the raceway is vertical. Your bend should be perfect. If it isn’t, move the hickey slightly and adjust the bend.