Can Neutral and Ground Wires Be Connected Together?

Sean Jarvis
by Sean Jarvis
Electrical work is extremely important and can create health and fire risks if you do it wrong. For example, you cannot connect a neutral wire to a ground wire without creating a major fire risk for the appliance. Whether it be identifying wires or understanding the risk, follow along as we explore why it’s not safe to connect a neutral wire to a ground wire.

A neutral and ground refer to wires that are part of an electrical system.

It is dangerous for neutral and ground wires to be connected together as it makes the ground wire live. When both the neutral and ground wires are live, it can start a fire or increase the risk of electrical shock. The only place neutral and ground wires should connect is the main panel, the last point of disconnect.

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Understanding Electrical Wiring

Standard wiring in the United States is done with plastic-sheathed cables. These cables typically have three conductors. Referred to as NMB cable, it also goes by its brand name, Romex.

Two of the conductors in Romex cable are covered with plastic insulation and the third is bare copper wire. They are distinguishable by their color, one white and the other black.

  • The hot wire is black and this provides a 120 VAC current source.
  • The neutral wire is white, this provides the return path for the current provided by the hot wire. This wire is connected to the earth ground.
  • The bare wire is the ground wire. Similar to the neutral wire, this is also connected to the earth ground.

Ground Wire

A ground line (also referred to as an Earth line) in an electrical wiring system is a conductor that provides a low-impedance path to the earth to prevent dangerous voltages from happening.

A ground wire isn’t required but is used as a safety feature. If the hot wire touches the chassis of an appliance, then when someone touches that appliance the person will close the circuit. This will result in the person receiving a shock.

When the ground wire is connected to any metal parts in an appliance, this eliminates the shock hazard in the event of a short circuit. Having a ground wire that connects to the neutral at the breaker box gives the electricity an alternate path to flow. This is the only time that the ground and the neutral are connected.

It ensures that if something were to go wrong, the ground wire will carry the current back, blowing the breaker, and not going into your body.

Different Ways to Ground Electrical Current

Grounding is the action of electronically connecting something to a conductive object that is used to create a direct connection to ground. A ground rod is typically used for this, which can be made from different materials.

The most common ground rod materials are copper, due to their longevity. Ground rods can also be made out of galvanized steel, copper-bonded steel, and stainless steel. They come in both 8-foot and 10-foot lengths, with 8-foot being the most common.

Within the building, grounding connections of all electrical outlets are wired to one another and connected to the water piping. This ensures that all electrical equipment with exposed metal parts are electrically connected to each other and exposed to metal fixtures in the building.

Grounding Wires

Ground rods are great conductors of electricity and allow any dangerous electricity to flow into the ground, away from you or the electrical panel.

Under normal conditions, a grounding conductor does not carry any current. It is an important path for home wiring because it enables circuit breakers to trip more quickly, which adds a safety element. If your system uses a metal box then the pigtail method is the most secure. Both the receptacle and metal box are grounded. Ground wires are spliced together and attached with a pigtail to the box and receptacle.

For a long time, ceiling fixtures were not required to be grounded. Recent code additions now call for grounding in these electrical fixtures. To do so, connect the fixtures ground lead to the strap on a metal box or to a ground wire.

Within switches, you will ground the wire using a connecting screw. Most older switches are not grounded and do not have a ground screw. To update your electrical system to be the safest possible you should upgrade switches around your home.

Many old homes also use the antiquated, and more dangerous, two-prong design. Without the grounding ability, this increases the chances of electrical shock during short circuits, ground faults, and electrical overloads.

Neutral Wire

In normal three-wire single-phase power systems, the neutral wire is one of three connections at a wall outlet. These three connections are the “hot”, “neutral”, and “grounding” wires.

The neutral wire forms a part of the live circuit, along with the hot wire. Most equipment requires only the hot and neutral wires to function. The grounding wire is used as a safety precaution, connected to exposed metal parts on the equipment to reduce the chance of shock.

In a 3-wire system, the hot and neutral wires are interchangeable. Both carry power and one of which is grounded at the source. The reason that the two wires are labeled differently is to identify which is grounded.

A Neutral is a circuit conductor that completes the circuit back to the source. It is usually connected to the ground at the main electrical panel and at the final step-down transformer of the supply.

All neutral wires of the same grounded electrical system should have the same electric potential, since they are all connected through the system ground.

Electrical Outlets

The Hot, Neutral, and Ground wires within a standard NMB cable are connected to the three prongs of an electrical outlet.

The neutral and hot wires are connected to the two vertical prongs. The ground wire is connected to the round prong at the bottom. This order matches the same order within the electrical receptacle. The Neutral wire will be on the left, the hot wire will be on the right.

For plugs that only have two prongs, these are used by appliances that don’t require grounding. Most non-grounded appliances have two layers of insulation between live wires and any metal parts within the appliance, which makes them double-insulated.

This is why it is not safe to plug a three-prong plug into a two-prong adapter (also known as a cheater plug).

Since regular two-prong plugs do not require a ground, their prongs are equal size. Three prong plugs have different widths (polarized) so that there is only one way to plug it in.

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Related Questions

Why are the prongs on my plug different sizes?

The hot side is connected to the house current and the neutral side is connected to the return path. If they are two different sizes, this prevents the hot and neutral from being switched.With older appliances, you are more likely to find 2-prong ungrounded plugs. With newer appliances, they are upgraded to the safer 3-prong plug.

What Happens if you Connect the Neutral to the Ground?

If there were a failure, then there is a possibility that the neutral could approach ‘hot’ voltage. This will cause electrocution if you were to touch the object, as your body would be used to complete the circuit.

How Far Can a Ground Rod Be from the Panel?

The shorter the distance to the ground rod, the more efficient the ground. Standard copper wire should be no smaller than No. 6, while most codes recommend No. 4 wire. If using 2 ground rods, they should be spaced at least 6 feet apart.

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Sean Jarvis
Sean Jarvis

Sean Jarvis is an interior decorator, writer, and expert handyman. Well versed in everything home improvement, he is a savant at manipulating words and spaces and upgrading everything around him. Sean specializes in writing concise guides about appliance repair and installation, home and lifestyle, and other residential projects.

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