Once conduit is in place, or if you plan to install a new electrical outlet in a wall, you're going to need to run or "fish" electrical wiring. There may be obstacles along the way to getting the job done, but they're not something that can't be overcome. This article will take a look at running building wire through conduit, as well as running it through finished walls and some of the potential problems.
When running electrical building wire through conduit, there are a few things you'll want to consider: the length of the run, how many curves and corners are in it, how stiff it is, and more. A very effective way to run wire through conduit is with the use of a fish tape, which is a long, flat, thin wire wound inside a circular shaped wheel with a handle on it. Commonly 50' or 100' in length, a fish tape is used to pull or "fish" wire through the conduit from one end to the other.
To fish wire through conduit, start by feeding the fish tape into and through the conduit until it comes out the other end of the raceway. Working with a partner, that person attaches the wire to be pulled to the end of the fish tape. The tape has a hook on it to which the electrical wire is attached by looping it through the hook and twisting the electrical wire around the end of the hook.
At this point, use electrical tape to wrap around the wire and the tape hook to firmly secure the wire to the fish tape. Once secured, wire lubricant can be applied to the wire's surface to make fishing the wire through the conduit smoother and easier. After securing the wire to the hook and applying lubricant, simply rewind the fish tape back into the reel with the wire in tow.
If fishing multiple wires through the conduit, use the same method for a single wire, but strip off enough insulation so the multiple wire ends can be wrapped around the fish tape hook and secured with electrical tape. After securing, be sure wire lubricant is applied and slowly and methodically reel in the tape. Only reel in about 3' at a time and then stop to ensure your partner feeding the wire into the conduit isn't getting wires tangled, while also taking time to apply more lubricant as you go. Reeling too fast can lead to cuts or abrasions to the wire's insulation, and working slowly allows the lubricant to better do its job.
While fishing electrical wires through a raceway is a rather straightforward process, there are times when wires need to be fished or run through finished walls—including any obstacles present. Here's a look at three possibilities if, for instance, you need to run electrical wire to a new light switch midway up the wall or to an outlet at the bottom of the wall. In all instances, for the easiest way to do it and best results, start at the top of the wall if possible.
Running Wire through a Finished Wall
Access the top horizontal beam of the wall and drill a hole large enough to feed the electrical wire through. Next, identify the location for where the mud ring will be installed on the wall, mark it off, create the cutout with a drywall saw and install the mud ring. Now, feed the fish tape or drop the fish rod through the hole in the horizontal beam, ensuring that either tape or rod extends well beyond the hole in the beam and can be accessed through the mud ring below.
Grab the tape or rod and pull it through the mud ring opening. Secure the wire to be pulled through the hole in the beam to the hook on the end of the tape or rod, and fish or pull it through the mud ring and hole in the beam for connecting to complete the run.
Running Wire through a Finished Wall with a Firestop
A firestop in a wall is a piece of 2x4 placed horizontally between two wall studs. It's designed to prevent a fire from spreading from floor to ceiling if one occurs. To bypass a firestop and run a wire, a specially designed 6' fish bit or flex bit is needed. What makes the design special is that, in the bit itself and at the top where the shank is inserted into the drill chuck, there is a hole to which the wire that is being installed can be secured.
Drill the hole in the beam and install the mud ring the same as above. With the hole beam drilled, attach the flex bit to the drill, feed it through the beam hole, and drill a hole in the firestop. Now attach the wire to the hole in the shank at the top of the bit, feed the bit and the wire through the hole in the firestop until the bit head is accessible through the mud ring. Reach in and pull the bit and wire through the mud ring to finish the fishing run.
Running Wire through a Finished Wall with Insulation
Fishing a wire through fiberglass insulation is a little trickier and requires a special magnetic pulling tool. Begin the same as you would in each instance above, but use a 1-1/4" spade bit to drill a hole on the top horizontal beam and also lower on the wall where you want the wire to exit. Once the top hole is drilled, attach the wire to be run to the special magnetic leader with a rare earth magnetic "bullet" at the end of it. Begin feeding the "bullet" through the hole into the wall cavity to get it started.
Now use the rare earth magnet roller with the handle on the other side of the wall to locate the "bullet". Once the "bullet" and roller are aligned, the extremely strong magnetic bond between the two allows you to slowly work the leader and "bullet" down the wall, past the insulation, and to the hole where it can be pulled through the exit hole to complete the fishing run.
While it can seem to be a daunting task, running or fishing electrical building wire can be done with a little patience and the right tools to effectively complete the job.
Product Compliance and Suitability
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