Open grounds are commonly found in older homes where the older electrical wiring has not been fully updated to newer grounded wiring. However, open grounds can be found in newer homes, too, where a founding wire is loose, breaking the connection between the receptacle and the electrical panel box. But what exactly is an open ground, and how do you troubleshoot and fix it?
An open ground is when you have a three-prong receptacle that is not connected to an equipment grounding conductor. It creates safety issues since the appliance designated to use an equipment ground to discharge an unsafe fault condition will not have a conductor discharge that fault.
Open grounds occur in two main instances:
- there is no grounding wire present
- there is a break in the grounding connection caused by a loose or broken wire.
The faulty current carries voltage above the standard voltage flowing in a regular electrical circuit in an open ground situation.
What Does an Open Ground Mean?
In an open ground situation, the open ground has little to do with the three-prong receptacle outlet. The outlet doesn’t provide grounding; the wiring does.
I know it’s pretty vague now, but you’ll understand open grounds better as we move along.
The National Electrical Code dictates that every electrical outlet and fixture in residential buildings must be grounded. Grounding enables faulty current, which would otherwise be dangerous above ground, to safely find a path to discharge unwanted current to the ground.
A receptacle is an electrical socket or a wall plug outlet that is usually installed on walls. The purpose of a case is to discharge electric power from a circuit for home consumption by powering electrical devices and household appliances.
There are two most common and popular types of receptacles/sockets:
- Two-prong receptacle (outdated)
- Three-prong receptacle
Two-prong Receptacle (outdated)
The two-prong receptacle is outdated and goes way back to the 1960s, but it is still widespread as it is still present in older homes’ wiring systems.
Many homeowners don’t want to go through the hassle of replacing it as long as it’s working. On the other hand, some people are trying to upgrade by replacing them with a three-prong receptacle.
The two-prong receptacles are considered unsafe because of their lack of grounding. Unlike the two-prong, the three-prong is meant to connect to a home’s grounding system.
A three-pronged receptor has two aligned but uneven slots on the top space and one “U’’ shaped place on the bottom area. The larger slot on the left is “neutral,” the smaller slot on the right is “hot,” and the “U” shaped place on the bottom is “ground.”
In summary, the open ground is any faulty current or circuit that does not route to the ground. Meaning, safety from electric shocks and damage is not present or guaranteed.
Is Open Ground Dangerous?
An open ground is dangerous. Anything that has electricity or conducts electricity is dangerous and needs to be handled with enough caution.
An open ground as an electrical product is unsafe.
Most open-ground problems go unnoticed until it either inflicts shock on someone or causes a sudden fire.
That is why it is crucial to do a frequent home inspection on your property.
What is a Grounding Wiring System?
A grounding system is a part of a home’s electrical wiring system. It installs electrical cables and associated devices such as switches, distribution boards, sockets, and light fittings in a building/home.
The primary and most important purpose of earthing or grounding is to reduce the dangers of electrocution and fires that could potentially destroy homes. An electrical system that is adequately grounded ensures safety to lives, electrical wires, and electrical devices.
During wiring, three types of wires are used;
- Live Wire (Red or Black Color)
- Neutral Wire (White Color)
- Ground/Earth Wire (Green Color or Bare Copper)
A live/hot wire is an active wire that carries electrical current in the form of voltage. Live wires are red to alert people of the danger they pose.
Neutral and earth wires alternate/circulate current in an electrical system. While the neutral wire brings the circuit to a ground/bus bar connected to the electrical panel, the earth wire provides an electrical connection to the ground. The purpose is to provide a path for faulty current to flow to the ground.
What is a Grounding Rod?
A grounding rod is a thick wire that has meager resistance. It acts as a line of defense against the various safety risks a faulty may pose and is, therefore, a crucial wiring part to have a complete and safe electrical system.
There are various types of rods installed according to different environmental conditions.
Types of Grounding Rods
- Stainless steel grounding rods
- Solid copper grounding rods
- Copper-bonded grounding rods
- Galvanized grounding rods
The copper-bonded grounding rods and galvanized grounding rods are pretty much the most common types worldwide.
But the stainless steel grounding rods and solid copper grounding rods are set aside to meet the needs of regions with unique weather conditions.
In a grounding system, the grounding rod installation is involved.
A grounding rod called a grounding electrode is usually installed in the ground very close to the main electrical servicing board.
Its primary purpose is to provide fault current with a low resistance path to deposit unwanted or excess and unsafe draft to the ground.
Grounding rods are either 8-foot long or 10-foot long, but the 8-foot is commonly used in residential wiring installations.
When installing the grounding rod, one must first find a suitable location near the house and closer to the service panel.
For proper installation, at least ¾ of the rod length is driven deep into the moist ground. A flexible grounding wire that goes directly to the distribution panel system inside the house is attached to the protruding end.
What is Fault Current?
A fault current is an unintended situation that happens when one electrical conductor or more transmits to itself, to each other, or the ground.
It is not uncommon to experience a fault current in an electrical circuit—the presence of an open ground result in accidental electric shocks and device damages.
Electric current is the normal systematic flow of electrons, electric charges between two different points through an electric wire.
This current is measured in amps, with electric charges flowing between point A and point B.
A service panel receives incoming electric power from the utility company through the primary meter in any regular electrical circuit. It distributes each of the courses that supply the various household’s lights, outlets, appliances, and other devices throughout the house.
The circuit then flows back to the panel where circuit breakers are installed. These circuit breakers interrupt any faulty current flowing in by cutting off the power supply, interrupting the circuit.
Other electric fault devices include:
A Fuse is a small but effective electrical safety device containing a strip of wire that heats up and melts to break the electric circuit when it encounters a faulty current.
It protects both the wiring and the appliance because a current in a faulty condition carries more current than an average electric current should.
Fuses are not used widely now that circuit breakers have replaced them.
On the other hand, an electrical relay is a control switch with a set of input and contact terminals used to stabilize electric current in electrical circuits.
Its purpose is to make contact with one circuit as it breaks contact with another.
Types of Electric Fault Currents
When you talk about electrical faults, many tend to think that it is just one type and are surprised when they learn that there are several but different types of defects:
- Phase to ground
- Double phase to ground
- Three-phase to ground
- Phase to phase
- Three phases
What Danger Can Fault Electrical Current Pose?
In a typical electric setup, electric current flows through a cable, and different wires have an additional carrying capacity.
Standard cable sizes include 14-, 12-, 10-, 8-, 6-, and 2-gauge wire. The wire size dictates the amount of current that can safely pass through it at a given time. A Wire gauge is directly related to how many amps you need to run through it.
And because faulty current results in a condition where the voltage (amps) flowing through the cable surpasses its carrying capacity, several damages might happen:
- Cable damage.
- Electrical circuit damage.
- Electric shock.
Finding and Testing For an Open Ground in a House Circuit
In finding and testing for open ground, electricians‘ best tool or instrument is an outlet testing tool.
In an ordinary electrical circuit system, an excess flow of current charge is anticipated to occur. This excess and unwanted current is known as fault current.
Fault current can damage electrical cables in the electric circuit, causing damage to household appliances connected to the outlets. It may also hurt people if left unmanaged.
The grounding system, by default, provides this faulty current with a path to safely deposit to the ground instead of causing a safety hazard. That is why the National Electrical Code stresses the need to ground all electrical outlets.
The service distribution panel is the central unit for all electrical connections within a home. From this point on the wall, the distribution panel feeds from the main meter located outside, dissipates excess voltage to the grounding system, and supplies different home parts through other electrical circuits.
- It is crucial that a certified electrician handles this task of troubleshooting and fixing an open ground for safety reasons.
- Grounding is mainly connected to outlets, and these outlets happen to be receptors/sockets. To find out the source of open ground, the electrician must first locate every outlet within the home.
- When he does locate an outlet, he will insert an outlet tester into a receptacle to determine if the outlet box contains a grounding wire that is not doing its job of routing insufficient current to the ground.
- An outlet tester has three light indicators. The indicator in the middle comes on if a grounding wire in question is not routing inadequate or faulty current to the ground.
- One by one, the electrician will keep testing every other outlet until he finds the one with the problem.
How Do You Fix an Open Ground?
Fixing an open ground in an outlet requires an electrician to trace the grounding connection to locate the loose or broken connection.
Electric outlets are found in almost every room within the home, but they are mainly located to access appliances easily. A receptacle will be located on one or two living walls where the television is supposed to be placed.
You will also find a receptacle for both cooker and the fridge at a designated point in the kitchen.
Inside an outlet or receptacle are three different colored wires that are terminated under other colored screws:
- A black wire (hot) is screwed onto a golden terminal.
- A white wire (neutral) is screwed onto a silver terminal.
- A green wire (ground) is screwed onto a green terminal.
Different colored wires and terminals ensure that no mistakes are made during a connection, and specific wires must go into particular terminals.
- Before an electrician disengages an outlet, he will first switch off the electricity supplying the room.
- When a receptor has an open ground, the green wire will either be loose or be completely disconnected.
- If it is loose, the electrician will use the correct screwdriver as dictated by the colored screws holding the terminal in place. Some screws are starred while others are flat; the same is with screwdrivers.
- And if the green wire has come out ultimately, he will unscrew the green receptor to make room for the green wire.
- He will carefully insert the wire on the slot beneath the screw, then hook it tightly.
- The electrician will then replace the cover of the receptacle then switch the electricity back on.
- To ensure that the repair was successful, the electrician will plug the outlet tester back into the receptor. If the middle indicator does not illuminate while the two on both ends do, it means your problem has been successfully fixed.
When Do You Need an Electrical Safety Inspection?
There are certain times when you need an electrical safety home inspection. The Electrical Safety Foundation suggest you book for review during these times:
- During the purchase of a new home
- If a home is over 40 years old
- After completion of a major renovation
- When adding appliance
Grounding electrical wires is a must. It is according to the National Electrical Code. Grounding the wires will ensure the safety of lives and property.
Most homeowners carry out inspections of their property when they want to sell it off. But most of them are oblivious of open ground problems and only become aware of them during a home inspection.
The home inspection is conducted by either a building inspector or by a certified electrical contractor.
They conduct a thorough inspection of all your electrical systems, ensuring all electrical wires and components are up to the standards.
An inspector’s job is to check if:
- The service unit is carrying enough current to supply the entire household sufficiently.
- The wiring system is in good working order.
- The wiring has a grounding system.
Often, after an examination, the electrical inspector will provide a detailed checklist of where it needs immediate attention or even where it needs an upgrade.
As discussed earlier, the open ground is when you have a three-prong receptacle that is not connected to an equipment grounding conductor. It should be repaired to avoid safety issues or property damage.
It is documented that each year, at least 1000 people lose their lives through electrocution and electrical injuries.
Aside from the fatalities, there are also multiple reports of numerous cases of electrical domestic infernos.