Sparky's Journal

📅 May 6, 2026

The Difference Between Grounding and Bonding

Grounding and bonding are two of the most misunderstood fundamental concepts in the electrical trade and in the NFPA 70 National Electrical Code. Even though these concepts are used in nearly every electrical installation, confusion between the two remains common.

To truly understand the code book, you must understand what electricity is, how it behaves, and what our role is as electricians. We must understand why a conductor goes to one terminal and not another. Ultimately, it comes down to safety and protecting equipment and people.

Before we can understand grounding and bonding, we need to understand a few basic electrical ideas.

What Is Continuity?

Continuity is the presence of a complete and unbroken electrical path that allows current to flow. Think of it as a chain that's in a loop; if a link in that chain snaps and that loop is broken, the continuity is gone. 

Electricity can only move when there is a closed circuit. If that path is broken, current cannot flow.

For example:

• A wire connected from a breaker to a load and back to the source has continuity.

• If that wire is cut, disconnected, or damaged, continuity is lost.

Continuity is important because fault current must have a complete path back to the source in order for protective devices like breakers to trip. That's why we Bond. It's essentially a safe net for this surge of electricity that goes where we do not want it to go, and it immediately trips that breaker, stopping equipment from causing death or serious injury.

What Is Bonding?

Bonding is the intentional electrical connection of conductive parts to establish electrical continuity and conductivity.

In simple terms:

Bonding connects metal parts together so they are all at the same electrical potential.

A good analogy is welding.

Just as a welder bonds two pieces of metal together using a controlled electrical arc, bonding in electrical systems connects conductive components so they behave as one continuous electrical system.

Examples of bonded components include:

• Metal conduit

• Electrical enclosures

• Equipment frames

• Cable trays

• Metal raceways

Bonding ensures that if a fault occurs, all exposed metal parts remain at the same voltage potential, reducing shock hazards and providing a path for fault current.

What Is Grounding?

Grounding is the intentional connection of an electrical system to the earth.

The earth itself acts as a reference point for voltage.

Grounding is typically accomplished through components such as:

• Ground rods

• Concrete-encased electrodes (UFER)

• Ground plates

• Building steel

• Metal underground water piping

Grounding stabilizes the electrical system voltage and helps dissipate unwanted electrical energy from sources like:

• Lightning

• Static electricity

• Line surges

• High-voltage faults

What Is a Grounded Conductor?

A grounded conductor is a system conductor that is intentionally connected to ground.

In most electrical systems, this is the neutral conductor.

The neutral is grounded at the service equipment, so the electrical system has a stable reference to earth.

What Is a Bonded Conductor?

A bonded conductor is a conductor or metal component that has been electrically connected to other conductive parts to create continuity.

This includes:

• Equipment grounding conductors

• Bonding jumpers

• Metal raceways

• Enclosures

Bonding ensures all conductive parts remain electrically connected so fault current has a low-impedance path back to the source.

Are We Grounded?

Humans are not normally grounded in the electrical sense.

However, we can easily become grounded if we:

• Stand on earth

• Touch grounded metal

• Contact conductive building materials

If a person becomes part of a circuit between voltage and ground, current can flow through the body, which is why proper grounding and bonding are critical for safety.

What Is the Purpose of Grounding Equipment?

Grounding primarily serves to:

1. Stabilize system voltage

2. Provide a reference to Earth

3. Dissipate lightning and surge energy

4. Reduce voltage fluctuations

Grounding is not primarily intended to clear faults.

This is one of the biggest misconceptions in the electrical trade.

What Is the Purpose of Bonding Equipment?

Bonding exists to:

1. Create an effective fault current path

2. Ensure overcurrent devices trip quickly

3. Keep exposed metal parts at the same potential

4. Reduce shock hazards

When a phase conductor accidentally contacts metal equipment, bonding allows a large fault current to travel back to the source quickly, causing the breaker to trip.

Why Does This Matter?

Without proper grounding and bonding:

• Faults may not clear

• Equipment can remain energized

• Breakers may not trip

• Metal parts can become shock hazards

Grounding and bonding work together to protect both people and equipment.

Grounding establishes the system's reference to earth.

Bonding ensures fault current has a reliable path back to the source.

How Do We Implement Grounding and Bonding?

Grounding and bonding are implemented throughout an electrical system using:

• Grounding electrode conductors

• Grounding electrode systems

• Equipment grounding conductors

• Bonding jumpers

• Metal raceways

• Service bonding connections

These requirements are defined throughout the NFPA 70 National Electrical Code.

Where Does Grounding and Bonding Occur?

Key locations include:

• Service equipment

• Separately derived systems

• Panelboards

• Transformers

• Equipment enclosures

The main bonding jumper at the service equipment is where the grounded conductor (neutral) and the equipment grounding system are connected.

When Is Bonding Required?

Bonding is required whenever metal parts could become energized, including:

• Electrical enclosures

• Metal raceways

• Cable armor

• Structural metal

• Piping systems

This ensures any fault current has a safe path back to the source.

Who to Learn More From

Some of the best educators in the electrical industry include:

• Paul Abernathy

• Mike Holt

Both have spent decades teaching electricians how to better understand the why behind the code.

Books I Recommend

Some excellent learning resources include:

• Understanding the National Electrical Code by Mike Holt

• Electrical Grounding and Bonding by Phil Simmons

• NFPA 70 National Electrical Code Handbook by the National Fire Protection Association

✅ Core takeaway

• Grounding connects the electrical system to earth.

• Bonding connects metal parts together to create a fault current path.

Both are required to make an electrical system safe and effective.