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How to Wire an Electrical Outlet Under the Kitchen Sink: Fishing Cable

Bob Jackson
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by Bob Jackson

How to Wire an Electrical Outlet Under the Kitchen Sink – Fishing NM-B 14/2 cable from the basement circuit breaker panel to the kitchen sink cabinet. This project is continued from How to Wire an Electrical Outlet Under the Kitchen Sink – Part 4.

Having removed the old branch circuit wiring and GFCI electrical outlet, I’m ready to pull nylon fish tape from the kitchen sink cabinet through the basement ceiling crawlspace back to the circuit breaker panel. When the fish tape is pulled to the breaker panel, the new NM-B 12/2 cable will be attached to the tape and pulled to the kitchen sink. This is a 100 foot spool of 3/8 inch diameter fish tape:

Fish Tape under the Kitchen Sink to Pull NM-B 12/2 Cable
Fish Tape under the Kitchen Sink to Pull NM-B 12/2 Cable

Fishing Electrical Cable to the Kitchen Sink Cabinet

Fish tape is a means to thread a smooth, flexible and strong line behind walls, floors and ceilings along the path where the new electric cable will be installed. This is known as “fishing cable”. Fish tape is available in nylon, fiberglass and flat steel spools and as straight rods that screw together to suit the situation. The nylon fish tape is non-conductive and great for fishing along energized wires so there’s no risk of poking it in the wrong place and getting shocked.

I dropped the flashlight attached to a lanyard so I wouldn’t lose it through the hole in the bottom of the kitchen cabinet and used the dentist’s mirror tool to search for the hole in the subfloor to the basement ceiling crawlspace. The two holes were offset by several inches and with some finesse I was able to guide the nylon fish tape through the two holes:

Under Sink Outlet: Electrical Fish Tape through the Kitchen Cabinet and Subfloor
Under Sink Outlet: Electrical Fish Tape through the Kitchen Cabinet and Subfloor

I pushed about 20 feet of fish tape through the bottom of the kitchen cabinet:

Working off the ladder in the basement, I used a long fiberglass pole with a utility hook duct taped to the end to reach over and catch the fish tape. It was tricky but I was able to guide the fish tape over the cross-runs of NM-B cables to keep the new branch circuit off the suspended drywall ceiling since I won’t be able to fasten the NM-B cable with cable staples to the floor joists. The red square in the photo shows where the fish tape runs up through the subfloor to the kitchen cabinet.

Under Sink Outlet: Electrical Fish Tape to Pull NM-B Cable
Under Sink Outlet: Electrical Fish Tape to Pull NM-B Cable

I continued to pull the fish tape and guide it over the pipes and cables out to the basement wall:

Under Sink Outlet: Pulling Fish Tape in the Basement Ceiling Crawlspace
Under Sink Outlet: Pulling Fish Tape in the Basement Ceiling Crawlspace

I pulled the fish tape between the 2×4 wall studs for the drop to the circuit breaker panel:

Electrical Fish Tape Pulled Down to the Circuit Breaker Panel
Electrical Fish Tape Pulled Down to the Circuit Breaker Panel

Under Sink Outlet: Pull NM-B 12/2 Cable with Fish Tape

I needed about 35 feet of NM-B 12/2 cable plus some extra to allow for waste to wire the outlet under the kitchen sink. I purchased a 50 foot roll of NM-B 12/2 cable at my local home improvement store. 12 gauge NM-B cable has a yellow insulation jacket whereas 14 gauge NM-B is white. Remember that 12 gauge cable is required for a 20 AMP circuit.

50 Foot Roll of NM-B 12/2 Cable
50 Foot Roll of NM-B 12/2 Cable

I attached the NM-B 12/2 cable to the eye of the fish tape by snipping off the black and white insulated wires then twisting the ground wire around the eye:

Branch Circuit Wiring: Attach NM-B Cable to the Fish Tape Eye for Pulling
Branch Circuit Wiring: Attach NM-B Cable to the Fish Tape Eye for Pulling

The fish tape and ground wire are wrapped in a layer of duct tape to prevent snags on sharp edges when pulling the cable:

Branch Circuit Wiring: Fish Tape and NM-B Cable
Branch Circuit Wiring: Fish Tape and NM-B Cable

The 50 foot roll of NM-B 12/2 cable is laid on the basement floor and ready for pulling with fish tape to the kitchen sink cabinet:

Roll of NM-B Cable and Fish Tape Ready for Pulling
Roll of NM-B Cable and Fish Tape Ready for Pulling

Pulling the new NM-B 12/2 cable was easy. A helper in the kitchen pulled while I fed the NM-B cable into the crawlspace, being careful to prevent kinks and twists. The fish tape is noted by the red arrows:

Branch Circuit for Under Sink Outlet: Pull NM-B Cable with Fish Tape
Branch Circuit for Under Sink Outlet: Pull NM-B Cable with Fish Tape

The following photo is the new run of yellow NM-B 12/2 cable after pulling through the finished basement ceiling crawlspace. Note how I was careful to lay the cable over the cross-runs of white NM-B 14/2 cable to keep it off the suspended drywall ceiling. This is so the cable isn’t accidentally cut if I or someone else were to cut a hole in the ceiling to install a light or maintenance panel.

Had the crawlspace above the suspended drywall ceiling been accessible, I would have nailed wood guard strips across the floor joists to protect the cable, then stapled the cable to the joists between the guard strips. The best that I could when fishing cable in this inaccessible location was to route the cable as shown, which is allowed by the National Electrical Code.

Branch Circuit Wiring: NM-B Cable Pulled through Basement Ceiling Crawlspace
Branch Circuit Wiring: NM-B Cable Pulled through Basement Ceiling Crawlspace

The is the NM-B 12/2 cable as it goes up between the floor joists through the subfloor to the kitchen sink cabinet:

NM-B Cable Fished Through the Subfloor to the Kitchen Sink Outlet
NM-B Cable Fished Through the Subfloor to the Kitchen Sink Outlet

Success! NM-B 12/2 cable fished back to the kitchen sink cabinet:

Under Sink Outlet: Fishing NM-B Cable to the Kitchen Sink Cabinet
Under Sink Outlet: Fishing NM-B Cable to the Kitchen Sink Cabinet

I have a minor problem. The NM-B cable is in the wrong place because it’s in the middle of the kitchen sink cabinet. Bare cable cannot be exposed per the Electrical Code rules and it would look stupid to have the cable penetration here.

The new junction box and receptacle will be mounted on the back wall of the sink cabinet. The NM cable needs to penetrate the cabinet floor directly below the junction box. I drilled a 1 inch hole in the cabinet bottom almost directly above the hole in the subfloor with a wood boring drill bit to reroute the NM-B cable.

Drill a Hole in the Kitchen Sink Cabinet for the New Branch Circuit
Drill a Hole in the Kitchen Sink Cabinet for the New Branch Circuit

The NM-B 12/2 wire is attached to a spool of flat steel fish tape and covered with a piece of duct tape to prevent snags. The steel fish tape is stiffer than nylon tape and curved in the direction to reach the hole in the center of the cabinet:

Fishing the NM-B Cable to the Kitchen Sink Cabinet Wall
Fishing the NM-B Cable to the Kitchen Sink Cabinet Wall

I pulled the NM cable back down the center hole and up the new hole by the wall being careful not to kink the NM-B 12/2 cable as the loop pulled through the cabinet hole:

Under Sink Outlet: Fishing the NM-B Cable to the Wall
Under Sink Outlet: Fishing the NM-B Cable to the Wall

This project is continued in How to Wire an Electrical Outlet Under the Kitchen Sink – Part 6.

Take care,

Bob Jackson

branch circuitfishing NM-B cablehow to fish NM-B cablekitchen sink outletNM-B 12/2 cable
Bob Jackson
Bob Jackson
Technology product manager by day and a prolific handyman in the evenings and over the weekends. Bob was the founder of the original Handyman How To website and that tradition continues on this site with excellent new handyman content into the future.
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