A Leviton double pole switch (such as the 20A Leviton 5692-2W) simultaneously interrupts both ungrounded (hot) conductors of a 240V circuit. The wiring diagram routes Line 1 and Line 2 to the top brass terminals, and Load 1 and Load 2 to the bottom brass terminals, while the bare copper equipment grounding conductor bypasses the switch entirely and bonds to the green yoke screw. This configuration is standard for 240V baseboard heaters, window AC units, and heavy-duty workshop equipment.

Leviton Double Pole Switch Wiring Diagram: Node-by-Node Trace

To wire this correctly, you must trace the current path from the panel to the appliance. A double pole single throw (DPST) switch does not switch the neutral; it only breaks the hot legs. Here is the exact node-by-node trace for a standard 240V, 20A load:

  1. Source (Panel): A 2-pole 20A breaker provides two 120V legs (L1 and L2) that are 180 degrees out of phase, yielding 240V between them.
  2. Line-Side Conductors: Two 12 AWG THHN hot wires (typically Black and Red, or Black and White re-identified with black tape) enter the switch box.
  3. Switch Input (Line Terminals): The Black wire lands on the top-left brass screw. The Red wire lands on the top-right brass screw.
  4. Internal Mechanism: When the toggle is thrown to 'ON', the internal contacts bridge the top and bottom terminals on both sides simultaneously.
  5. Switch Output (Load Terminals): The current exits via the bottom-left brass screw (Black wire to appliance L1) and bottom-right brass screw (Red wire to appliance L2).
  6. Load (Appliance): The 240V potential drives the heating element or motor.
Ground Path Callout: The Equipment Grounding Conductor (EGC) never passes through the switch mechanism. The bare copper ground from the panel lands on the metal box's grounding screw, and a 12 AWG green pigtail runs from the box to the switch's green grounding screw. This ensures the switch yoke and faceplate remain at earth potential even if an internal fault occurs.

What the Diagram Symbols Mean

On an electrical schematic, a double pole switch is represented by the DPST symbol. You will see two parallel single-pole switch symbols (a line breaking into a gap with a hinged lever) connected by a dashed or solid horizontal line. That connecting line represents the mechanical linkage of the physical toggle—indicating that both circuits open and close at the exact same time. If you see a circle with a slash through it near the symbol, it denotes a 'maintained' contact (standard toggle), as opposed to a momentary push-button.

Terminal Mapping and Physical Device Identification

When holding a physical Leviton 5692-2W (or similar 15A/20A double pole toggle), the terminal layout is strictly standardized. Unlike 3-way switches, there are no 'traveler' terminals, and unlike smart switches, there is no neutral terminal. Below is the exact terminal mapping for the physical device.

Screw Color Physical Position Function Wire Type & Gauge
Brass Top Left Line 1 (or Load 1) 12 AWG Black (Hot)
Brass Top Right Line 2 (or Load 2) 12 AWG Red (Hot)
Brass Bottom Left Load 1 (or Line 1) 12 AWG Black (Hot)
Brass Bottom Right Load 2 (or Line 2) 12 AWG Red (Hot)
Green Bottom Center (Yoke) Equipment Ground 12 AWG Bare/Green

Note: While the switch is technically non-directional (it will function if Line and Load are swapped on the brass screws), NEC guidelines and best practices dictate that the power source (Line) enters the top terminals and the load exits the bottom terminals. This ensures consistency for troubleshooting and prevents back-feeding hazards during maintenance.

Step-by-Step Installation and Meter Verification

SAFETY WARNING: This procedure involves 240V mains voltage, which is lethal. De-energize the 2-pole breaker, apply a lockout/tagout device, and verify the circuit is dead with a known-working CAT III multimeter before touching any conductors. Local codes may require a licensed electrician for new 240V circuit installations.
  1. De-energize and Verify: Turn off the 2-pole breaker. Use a non-contact voltage tester (NCVT) on the wires in the box, then confirm with a multimeter set to V AC. Measure Line-to-Line (expect 0V) and Line-to-Ground (expect 0V).
  2. Prep the Box and Grounds: If using a metal gang box, land the incoming bare copper ground on the box's grounding screw. Crimp a 12 AWG green pigtail to this ground bundle. Route the pigtail to the switch.
  3. Land the Ground: Secure the green pigtail to the switch's green grounding screw. Torque to approximately 14 in-lbs (or until snug and the wire does not pull free with a firm tug).
  4. Terminate Line Conductors: Strip 3/4 inch of insulation from the incoming Black and Red wires. Form a J-hook and wrap clockwise around the top-left and top-right brass screws. Tighten firmly.
  5. Terminate Load Conductors: Strip and terminate the outgoing Black and Red wires to the bottom-left and bottom-right brass screws.
  6. Secure and Restore Power: Carefully fold the wires into the box (keeping grounds pushed to the back to avoid crowding the toggle mechanism). Screw the switch to the box, attach the faceplate, and restore power at the breaker.

How to Verify Each Connection with a Meter

Once power is restored, keep the switch in the 'OFF' position and perform these diagnostic checks using a CAT III or CAT IV multimeter (like a Fluke 117 or Klein MM700):

  • Line Voltage Check: Probe the top-left and top-right brass screws. You should read 240V AC (±5%). This confirms both breaker poles are live.
  • Polarity/Ground Check: Probe top-left to the green ground screw (expect 120V AC). Probe top-right to the green ground screw (expect 120V AC). This verifies your ground path is intact and the hot legs are correctly referenced to earth.
  • Load Isolation Check (Switch OFF): Probe the bottom-left and bottom-right brass screws. You should read 0V AC. If you read 240V here with the switch off, the internal contacts are welded shut (failed switch) or it is wired backward and you are probing the line side.
  • Switched Output Check (Switch ON): Flip the toggle to 'ON'. Probe the bottom brass screws. You should now read 240V AC, confirming the load is energized.

Frequently Asked Questions

Can I use a Leviton double pole switch for two separate 120V circuits?

Yes, but with strict caveats. This is common in Multi-Wire Branch Circuits (MWBC) where a single 120/240V feeder supplies two separate 120V receptacles. By wiring L1 to one side of the switch and L2 to the other, you can kill power to both 120V circuits simultaneously. This satisfies the NEC requirement for simultaneous disconnect on MWBCs. However, both circuits must originate from the same 2-pole breaker (or have handle ties) to prevent a shared neutral from overloading if one breaker trips while the other remains live.

Does a double pole switch need a neutral wire?

No. A standard mechanical double pole switch (like the Leviton 5692) only breaks the ungrounded (hot) conductors. The neutral wire (white) is not switched; it should be wire-nutted together in the back of the box and run continuously to the appliance. The only exception is if you are installing a 240V smart switch or a timer switch that requires 120V to power its internal Wi-Fi/clock electronics, in which case a neutral is required for the switch's own operation, not for the load.

What happens if I wire the line and load backward on a Leviton DP switch?

Functionally, a standard mechanical toggle switch is bidirectional; the appliance will still turn on and off. However, wiring it backward (power entering the bottom terminals, load exiting the top) violates standard electrical conventions. During future troubleshooting, an electrician will assume the top terminals are the live source. If they test the top terminals with the switch OFF and find 0V, they might falsely assume the breaker is dead, when in reality, the live 240V is sitting on the bottom terminals. Always maintain Line-in-Top, Load-out-Bottom for safety and code compliance.