A switched outlet (half-hot receptacle) uses a single-pole switch to control one half of a duplex outlet while the other remains constantly powered. The critical physical action is breaking the brass hot-side tab on the receptacle. Modern NEC-compliant wiring requires a 3-conductor cable (like 14/3 NM-B) for the switch leg to provide a neutral at the switch box per NEC 404.2(C). Below is the exact node-by-node trace, terminal mapping, and multimeter verification protocol to wire this safely on a 15A or 20A branch circuit.
The Core Wiring Diagram for a Switched Outlet (Half-Hot Receptacle)
Before touching a wire, you must understand the symbols and the physical path of the current. In standard electrical schematics, a power source is represented by a circle with radiating lines, a single-pole switch is a break in a single line with a hinged lever, and a receptacle is depicted as two parallel circles (representing the top and bottom duplex slots). A ground path is always indicated by a line ending in three descending horizontal bars or a downward-pointing arrow.
Node-by-Node Trace: Source to Load
This trace assumes power enters the switch box first, using 14/2 NM-B for the source and 14/3 NM-B for the switch leg (the modern code-compliant method).
- Node 1: Power Source to Switch Box. 120V AC enters the switch box via 14/2 cable. The black (hot) wire connects to the bottom brass terminal of the single-pole switch. The white (neutral) wire bypasses the switch and splices directly to the white wire of the outgoing 14/3 cable.
- Node 2: The Switch Leg (Switch to Receptacle). A 14/3 cable runs from the switch box to the receptacle box. Inside the switch box, the black wire of the 14/3 connects to the top brass terminal of the switch (this is your switched hot). The red wire of the 14/3 is wire-nutted directly to the incoming source black wire (this is your constant hot). The bare ground wires are all bonded together and to the metal box/switch yoke.
- Node 3: Receptacle Box - Constant Hot. The red wire from the 14/3 cable (constant hot) connects to the bottom brass screw of the duplex receptacle.
- Node 4: Receptacle Box - Switched Hot. The black wire from the 14/3 cable (switched hot) connects to the top brass screw of the receptacle. Critical step: The brass break-off tab connecting the top and bottom brass screws must be snapped off with needle-nose pliers to isolate the two halves.
- Node 5: Receptacle Box - Neutral and Ground. The white wire from the 14/3 cable connects to the silver neutral screw. The bare copper ground wire connects to the green ground screw on the receptacle yoke and bonds to the metal box if applicable.
Terminal and Pin Mapping: Physical Device Connections
Misidentifying terminals is the most common cause of dead outlets or tripped breakers. Use this spec-sheet table to verify every physical connection on your 15A (or 20A) devices. Note that standard duplex receptacles have brass screws on one side (hot) and silver screws on the other (neutral). Never reverse these polarities.
| Device | Terminal / Screw Color | Function | Wire Color Connected | Break-Off Tab Status |
|---|---|---|---|---|
| Duplex Receptacle | Top Brass | Switched Hot (Top outlet) | Black (from 14/3 switch leg) | Tab MUST be removed |
| Duplex Receptacle | Bottom Brass | Constant Hot (Bottom outlet) | Red (from 14/3 switch leg) | Tab MUST be removed |
| Duplex Receptacle | Silver (Either) | Neutral Return | White (from 14/3 switch leg) | Silver tab MUST remain intact |
| Duplex Receptacle | Green | Equipment Ground | Bare Copper | N/A |
| Single-Pole Switch | Bottom Brass | Line In (Constant Hot) | Black (from 14/2 source) | N/A |
| Single-Pole Switch | Top Brass | Load Out (Switched Hot) | Black (from 14/3 switch leg) | N/A |
| Single-Pole Switch | Green | Equipment Ground | Bare Copper | N/A |
Step-by-Step Installation and Meter Verification
Physical Wiring Steps
- Prep the Receptacle: Use needle-nose pliers to grip the small brass fin (break-off tab) between the top and bottom brass screws on the receptacle. Bend it back and forth until it snaps off. Leave the silver neutral tab completely intact.
- Strip and Loop: Strip 3/4 inch of insulation from all 14 AWG solid copper wires. Form a clockwise hook (J-hook) at the end of each wire using the stripping tool's hole loop.
- Make Connections: Hook the wires clockwise around the terminal screws so that tightening the screw pulls the loop closed. Torque terminal screws to manufacturer specs (typically 12-16 in-lbs for 15A devices) to prevent thermal loosening.
- Splice Neutrals and Grounds: Use appropriately sized wire nuts (e.g., yellow for two 14 AWG wires) to splice the neutral pass-through in the switch box. Ensure no bare copper is exposed outside the wire nut.
Multimeter Verification Protocol
Before restoring power, use a CAT III rated multimeter to verify your connections. Set the meter to Continuity (the diode/sound wave symbol).
- Test 1 (Switch OFF): Place one probe on the top brass screw (switched hot) and the other on the silver screw (neutral). The meter should read 'OL' (Open Loop / Infinite resistance). This confirms the switch is open and the circuit is broken.
- Test 2 (Switch ON): Toggle the physical switch to ON. Repeat the probe placement. The meter should now beep and read near 0.0 ohms, confirming a continuous path through the switch and the load.
- Test 3 (Constant Hot Isolation): Place a probe on the bottom brass screw and the silver screw. It should read 'OL' regardless of the switch position, confirming the constant hot is isolated from the neutral until a load (like a lamp) is plugged in.
Once continuity is verified, restore power at the breaker. Set your meter to AC Voltage (V~). Measure Hot-to-Neutral on the bottom receptacle (should read 114V-126V). Plug a lamp into the top receptacle; it should only illuminate when the wall switch is toggled ON.
Switched Outlet Wiring FAQ
Can I use a wiring diagram for a switched outlet with 14/2 cable instead of 14/3?
Historically, electricians used 14/2 cable for the switch leg, re-identifying the white wire with black electrical tape to serve as the switched hot. However, the National Electrical Code (NEC) now requires a neutral conductor to be present at the switch box (NEC 404.2(C)) to accommodate smart switches and timers. Using 14/3 cable provides a dedicated neutral (white), a constant hot (red), and a switched hot (black), making it the only fully code-compliant method for new installations in 2026.
What happens if I forget to break the brass tab on the receptacle?
If you wire the constant hot to one brass screw and the switched hot to the other brass screw but forget to snap off the connecting tab, you will create a direct dead short between the constant hot and the switched hot when the switch is turned ON. This will instantly trip the 15A or 20A circuit breaker, cause a loud pop, and potentially melt the terminal screws or damage the switch contacts. Always verify the tab is removed before energizing the circuit.
How do I wire a switched outlet where the power enters the receptacle box first instead of the switch?
When power enters the receptacle box first, you must run a 14/3 cable from the receptacle to the switch. At the receptacle, splice the incoming black (constant hot) to the red wire of the 14/3 and the bottom brass screw. Connect the black wire of the 14/3 to the top brass screw. The white wire of the 14/3 connects to the incoming neutral and the silver screw. At the switch box, the white and black wires of the 14/3 connect to the two brass terminals on the single-pole switch, and the red wire is capped off with a wire nut as a spare. This configuration maintains the required neutral at the switch box while correctly routing the switch loop.
