Installing Leviton Smart Breakers in a 120/240 V Panel: Step‑by‑Step Guide

How to Wire 1‑Pole & 2‑Pole Smart Breakers in a 120/240V Smart Load Center

Upgrading your home electrical system with Leviton’s 2nd‑Generation Smart Circuit Breakers adds a layer of intelligence that traditional breakers simply can’t match. Integrated with the My Leviton app, these breakers give you remote on/off control, real‑time energy monitoring, circuit‑level analytics, scheduling, and over‑the‑air firmware updates—all while maintaining the same robust protection you expect from a standard breaker.

Below you’ll find a detailed, safety‑first wiring guide for both 1‑pole and 2‑pole Leviton smart breakers in a 120/240 V residential panel. Before you begin, we’ll explain what smart breakers are, why they’re beneficial, and how they differ from conventional devices.

What Is a Smart Circuit Breaker?

Unlike conventional thermal‑magnetic breakers, which merely trip under overload or short‑circuit conditions, Leviton’s smart breakers fuse protective hardware with embedded electronics and communication modules. They enable:

Remote on/off control and scheduling via Wi‑Fi or Bluetooth
Trip notifications and fault diagnostics
Load classification (essential vs. non‑essential) for backup‑power scenarios
Automatic load shedding during generator or battery events
Patented reset‑lockout that blocks reset while a fault remains
Line‑side LEDs that display trip status even when the breaker is off

Smart breakers come in 1‑pole and 2‑pole variants, covering a range of applications—from basic thermal protection to GFCI, AFCI, surge, and dual‑function devices. They support 120/208 V and 120/240 V circuits and work in tandem with Leviton’s Whole‑Home Energy Monitor (LWHEM‑2) to provide per‑circuit energy data.

Key Features & Ratings

Model: 2nd Gen Smart Branch Circuit Breaker
Poles: 1‑pole & 2‑pole (2‑ or 3‑wire with ground)
Voltage: 120 V, 120/208 V, 120/240 V, single‑phase, 60 Hz
Current: 15 A to 60 A
Short‑Circuit Rating: 10 kA
Wiring: Plug‑on design
Control: Manual, remote on/off, scheduling
LED: Continuous status indicator
Compatibility: My Leviton app, Leviton Smart panels, LWHEM‑Hub

Step‑by‑Step Wiring for 1‑Pole & 2‑Pole Smart Breakers

The following diagram illustrates a 1‑pole 15 A, 120 V breaker (LB115‑ST) and 20 A / 50 A 2‑pole 120/240 V breakers (LB220‑ST & LB250‑ST) installed in a Leviton LP220‑BPD smart load center.

Wiring configurations:

15 A/120 V – 1‑pole, 2‑wire, single‑phase
20 A/240 V – 2‑pole, 2‑wire, single‑phase
50 A/120/240 V – 2‑pole, 3‑wire, single‑phase

Follow these steps for a safe installation:

Turn the main breaker OFF to isolate power. Verify the panel is de‑energized before touching any conductors.
Remove the panel cover to access the breaker slots and bus bars.
Ensure the new breaker’s handle is in the OFF position.
Snap the breaker into place, aligning the hooks with the bus bars until it seats fully.
Replace the panel cover and secure it tightly—never energize the panel without it in place.
Restore power by turning the main breaker ON, then switch the new smart breaker ON.
Attach the “Remotely‑Operated Circuit Breaker” label to a visible spot (no cover removal required).
Use the My Leviton app and the Getting Started guide to enable the breaker’s smart features.

Installing Leviton Smart Breakers in a 120/240 V Panel: Step‑by‑Step Guide

Smart Breaker LED Status Indicator

LED Color	State	Meaning
Green	OFF	ON (breaker closed)
Green – Solid	ON	Remote OFF
Red	OFF	Short‑circuit or overload trip
White	OFF	Manual OFF

These breakers are designed exclusively for Leviton load centers.
Smart functionality requires a Leviton Whole‑Home Energy Monitor (LWHEM‑2) or an LDATA hub.

Wiring Smart Breakers for Standard and Smart Outlets

The same wiring method applies when feeding outlets from smart breakers:

1‑pole 15 A, 120 V breaker → 15 A/125 V NEMA 5‑15 smart outlet (D215R)
2‑pole 20 A, 240 V breaker → 20 A/250 V NEMA 6‑20 standard outlet
2‑pole 50 A, 120/240 V breaker → 50 A, 125/250 V NEMA 14‑50 EV‑rated receptacle

Connect load conductors as follows:

Strip hot (black) and neutral (white) conductors to the recommended lengths (≈0.4 in. or 1 cm).
Attach hot to the brass terminal, neutral to the silver terminal, and ground to the ground bar.
Do not connect neutral to the panel’s main neutral bar at this stage; it must go to the breaker’s neutral terminal.

Wire sizes per NEC Table 310.16:

14 AWG for 15 A circuits
12 AWG for 20 A circuits
#6 AWG for 50 A circuits

Installing Leviton Smart Breakers in a 120/240 V Panel: Step‑by‑Step Guide

Using a Smart GFCI Breaker in a Standard Panel

If your panel isn’t a Leviton Smart panel, you can still add remote control with Eaton’s 2‑pole Wi‑Fi smart GFCI breaker (SBR260WGF). It protects a 60 A, 125/250 V NEMA 14‑60 receptacle while allowing smartphone control.

Installation parallels that of a standard 2‑pole GFCI breaker:

Mount the breaker on the main bus bars.
Connect the built‑in white pigtail to the panel’s neutral bus.
Run #6 AWG or #4 AWG conductors to the receptacle: black, red, white, and bare/green ground.

Ideal for EV chargers or other high‑load circuits that benefit from GFCI protection and Wi‑Fi control.

Installing Leviton Smart Breakers in a 120/240 V Panel: Step‑by‑Step Guide

Termination Chart

The chart below lists recommended wire sizes, strip lengths, and torque values for Leviton smart breakers. If you’re working with a different brand, consult that manufacturer’s manual or a licensed electrician.

Installing Leviton Smart Breakers in a 120/240 V Panel: Step‑by‑Step Guide

Safety Precautions

Never use a 15 A breaker on a 20 A circuit; it will trip unnecessarily.
Never use a 20 A breaker on a 15 A circuit; it allows unsafe current levels through undersized wiring.
Do not install a 20 A outlet on a 15 A circuit (except where code permits multiple 15 A outlets on a 20 A breaker).
Code permits 15 A outlets on 20 A breakers (NEC 210.21(B)(2)), but the reverse is prohibited.
A 2‑pole 240 V breaker can technically run a 120 V circuit, but it is not recommended. A 1‑pole breaker cannot run a 240 V circuit.
Do not mix three‑phase breakers with single‑phase circuits or vice versa.

Important Safety Notes

Always disconnect the main breaker before performing any work.
Consult a licensed electrician if you’re unsure about any step or local code requirements.
Electricity is dangerous—improper handling can cause injury, damage, or death.
The author disclaims liability for any loss or damage resulting from misuse of this guide.