The Methods Of Grounding A Home
Grounding is one of the most important safety steps for any electrical system. A properly grounded system protects people from shocks, appliances from surges, and structures from fire risks. During a catastrophic event like a lightning strike, electricity can take any possible path through your house.
A ground gives it a path with the least resistance, so the surge behaves predictably. Homeowners need to understand the potential methods of grounding so they can protect their investment in their residence.
Common Residential Methods of Grounding
Grounding Rod
Using a metal rod to connect the electrical system to the ground is easily the most common method. You will see this kind of ground particularly in older houses, and it is fading out of use with new construction. An eight-foot rod goes into the ground. A top wire connects the rod to a home’s electrical panel to provide a ground path for:
- Surges
- Transient voltages
- Electrical noise
- Fault currents
A notable benefit of using a rod as a ground is that the solution is easily expandable. You simply add another rod. Rods are also excellent for adding a ground to a building that didn’t previously have one, a common issue in many older houses from the 20th Century. Likewise, the replacement process is fairly straightforward because you simply replace an old rod with a new one. A new rod might be necessary due to corrosion. Also, the geological and hydrological features of the area can change, reducing the ground potential of the rod.
Ufer Grounding or Concrete-Cased Electrodes
An emerging technique in modern home construction is the Ufer ground. Copper materials go into the concrete that makes up a house’s foundation. The net effect is that the concrete acts as an electrode that then dissipates any surges into the ground. Some methods also involve putting a metal plate under the concrete.
By spreading out the effective area of the ground, concrete encasement offers better conductivity and lower resistance. The extra surface area and connection with moist soil also make the electrode more reliable. Understandably, this tends to be the least cost-effective of the common methods of grounding for a residence. However, it is a nearly permanent solution.
Cold Water Pipe Grounds
Another solution is to ground a house by connecting a clamp to the pipe that attaches the building to a municipal cold water supply. Since the municipal pipe is already in the ground, it provides a low-resistance path. The downside is that you can only use this method if your municipality uses pipes with a conductive metal. The upside is that it is a fairly cheap and accessible solution as long as there’s a municipal water line. A cold water pipe ground is a solid choice for retrofitting if the conditions are met.
Plate Grounding
Plate grounding is something of a middle ground between using a rod and using concrete-cased electrodes. It has the benefits of concrete-cased electrodes because it offers a high contact area. However, it is more cost-effective because you don’t have to encase the ground material in concrete. A plate is ideal for a location where the soil is dry because maximizing the contact area improves conductivity. Otherwise, the ground might not be sufficient.
Connected Safety Systems
Three common electrical safety systems connect to a home’s ground line. These protect your house against surges, shorts, and arcing.
Surge Protection
Whether you have a whole-house surge protector or rely on point-of-use systems like power strips, the safety benefits are only available through a properly connected ground. With a power strip, the round prong on the power cable connects to the ground. A whole-house surge protector connects to the electrical panel and provides a direct path to the ground, reducing the risk that a surge will go through your house.
Ground-Fault Circuit Interrupters (GFCIs)
GFCIs are common in wet areas around a house, and modern electrical code requires GFCI outlets within six feet of a:
- Sink
- Faucet
- Shower
- Bathtub
- Basin
- Spigot
- Toilet
All outdoor outlets also need GFCI support. You should also strongly consider GFCI outlets anywhere you perform food preparation, such as a countertop, even if it is more than six feet from a water source.
A GFCI detects when water is affecting the electrical path. It then turns the outlet off to reduce the risk that anyone touching the water will be shocked.
Arc-Fault Circuit Interrupters (AFCIs)
AFCIs detect when the electrical flow inside the circuit, usually in the wiring, has been interrupted. One common household scenario where an AFCI might trip is if someone drives a nail into a wall and hits a wire. By shutting off the circuit immediately, an AFCI reduces the risk that the electricity will arc inside the wall and cause a fire.
Considerations
All new home construction and nearly all new remodeling work require a house to meet the current National Electrical Code requirements. This means the electrical system has to be grounded, and appropriate safety systems like GFCIs have to be in place. Older homes are grandfathered in, but it’s wise to upgrade their systems. Common considerations for grounding projects include:
- Possible rewiring
- Electrical panel upgrades
- Adding a ground line
- Bonding all metal connections
- Addressing any code violations or updates
The bonding process should connect every metal system in the house to the grounding line. These systems include:
- Structural steel
- Plumbing lines
- Gas lines
- HVAC equipment
- Antennas or satellite dishes
- Metal well casings
- Service panels
- Pool equipment and structures
Choose Mister Sparky in Fort Myers
Mister Sparky proudly offers a variety of electrical services to folks in the Fort Myers, FL, area. From installations and replacements to repairs and maintenance, our electricians handle it all with integrity and skill. If the time has come to install a grounding system or to assess an existing one, we are here for you. Don’t put up with any malarkey, call Mister Sparky.
