HOW TO GROUND MAIN ELECTRICAL PANEL
Electricity has become so ubiquitous in our day-to-day life that we often don’t even think about it. With the rise of the ‘Internet of Things’ and the interconnected nature of modern technology, electricity becomes ever more important. An electrical failure is a bigger disaster now for a home than was the case twenty – or even ten – years ago.
There is an irony, however, in that as our lives are more dictated by electricity, we are losing the essential skills required to undertake basic maintenance to keep our home safe. Grounding the main electrical panel is a central part of ensuring your home is safe, and that the electrical supply to your home is functioning as it should.
In addition to keeping your home electricity running smoothly, a main electrical panel plays an important role in protecting it from dangerous electrical surges or malfunctions. Around 18% of civilian deaths from fires and 20% of property damage comes from fires involving electrical failures. This shows the clear value of proper maintenance.
This guide will walk you through the basics of grounding an electrical panel, including why it’s important, how to do it, and what steps to take if you find out that your electrical panel is not grounded. Most importantly of all, this guide will also show you the legal requirements involved in grounding an electrical panel, so that you can ensure your home is up to the legal standard.
WHAT'S AN ELECTRICAL GROUND?
The first thing to understand is precisely what is meant by an electrical grounding. As many of us learn in high school, to ground electricity is to safely discharge it into the earth. This is true in the case of a home. A grounded wire is one that allows for the safe dispersal of energy and provides a fallback for electrical surges. It also has a number of other practical purposes within the home.
The grounding wire is
what provides a reference point for the voltage of your electrical system. To give an example, if you use a voltmeter to take the voltage across the ‘hot’ and ‘neutral’ wire of your electrical system, you’ll most likely get a value somewhere around 120V. However, this measurement refers to the difference between the two values, not necessarily the absolute value of either.
If neither is grounded,
the ‘hot’ wire could be 520V and the neutral wire could be 400V and you’d get the same reading. Using the grounding wire gives you a guaranteed baseline of 0V, so you can ensure that your system is as safe as can be.
If you do not have a grounding wire – or if the grounding wire is damaged – the circuit breakers on the panel board will not work properly. These breakers are designed to ‘break’ or trip if there is a problem with the system (such as a surge of electricity or a short circuit). These are vital safety tools in a home. Without a grounding wire, these do not function properly and everything becomes that little bit more dangerous.
If you do not have a grounding wire, a short circuit would lead to potentially fatal levels of current being drawn into the system, making the electrical network in your home a deadly series of wires. Not only is there a major danger from touching the wires, but there is a strong chance of an electrical fire starting. A grounding wire is what underpins the fundamental safety setup of your home’s electrical network.
THE OVERALL COST
The average cost to have a professional ground a main electrical panel is between $200 and $1,000. The range is significant because the final price will depend on a number of factors including difficulty of accessibility and local codes.
HOW TO ADD A GROUND TO AN EXISTING PANEL
Because of the safety aspect of a grounded electrical panel, it is vital that you check whether yours is in place. In the vast majority of houses, there will be a grounded power outlet. However, in homes built before 1965 (when a grounded panel became the law in new homes), you may not have one in place.
The easiest way to check if your panel is grounded is...
to check the number of prongs. If you have two prongs, then it’s likely that there’s no grounding. The third prong is connected to the ground wire. If your outlets have only two prongs across the board, then you’ll need to check.
If you are in doubt or suspect that you may not have a grounded system, by far the best option is to call in a professional. They will be able to safely check your system, and consult on what the next best steps are.
Knob and Tube Wiring
If you have an older wiring system (known by professionals as ‘knob and tube’ wiring), an electrician will need to install a grounding rod and then connect this to a grounding conductor; this will, in turn, be connected back to your electrical panel. All of the two-prong outlets will be replaced with three-prong outlets, which may require a total rewiring of your system. The old wiring will be replaced with a non-metallic sheath cable. The sheath protects you against accidentally touching the wire and receiving an electric shock.
WHAT TO DO IF YOUR ELECTRICAL SYSTEM IS UNGROUNDED
As suggested above, the first sign you may have that your system is ungrounded is that your three-prong plug may not fit into the existing electrical outlets. Although the temptation may be to use an adaptor to fit it in, this is not a safe choice, nor is it a long-term one. Any adapter you may use has to be installed extremely precisely (i.e. by a professional) and can cease to be effective if it is jostled, moved, or in any way damaged.
Moreover, your appliances require three-prong plugs for a reason – it is to protect them. If you use an adapter, you will leave them vulnerable to surges and other malfunctions and will almost certainly void any warranty or insurance you may have.
A further option you may have if your panel is grounded, but you only have two-prong outlets, is to install Ground Fault Circuit Interruption (GFCI) outlets. These outlets are ‘smart outlets’ that detect any imbalance in the current flowing through. It monitors the difference between the hot and neutral wire and, if it finds a major difference between the two, it will pop a circuit breaker within the outlet.
This, therefore, operates as a form of grounding panel by itself within each individual outlet. Although this is not as safe as a full upgrade of your electrical system, it is a reasonable alternative that will give you many of the same safety benefits. In particular, it will greatly diminish the likelihood of an electrical shock entering your body.
LEGAL REQUIREMENTS FOR GROUNDING AN ELECTRICAL PANEL
If the safety requirements haven’t convinced you of the need for a grounded electrical panel, the legal code should.
Most insurance agencies will not insure any property that doesn’t have a grounding system, meaning if your home burns down, you will not receive any compensation. Moreover, the onus is on you as a homeowner to conduct the relevant inspections to ensure that you have a grounded electrical panel.
Most of the time, when you buy a home, the various surveys conducted will show up if the system is below a legal minimum. However, upon moving in, it’s well worth paying an expert to come and check the electrical system. This is doubly the case if you notice two-prong outlets in your new home.
If you are in any doubt, call the local city or county authority – they will likely have a plan to provide inspections to ensure you are up to code (although if they find a problem, you will have to pay to get it up to scratch).
Either way, you should be proactive about checking for a number of reasons – the legal requirement being only one of them.
The reasoning behind the strict rules on electrical grounding is straightforward:
Around 40% of fires involving electrical failures take place in the months of November through February,
demonstrating how simple activities like using hot water and heating your home can lead to electrical overload.
You should have your home professionally inspected on a regular basis to guarantee that the electrical panel is functioning as it should. Make this part of your home’s annual (or biannual) inspection process.
If you have an older home – or one with older wiring – you should expect to have some of the wiring replaced. Although this may seem expensive, it is well worth the cost, particularly when weighed against the potential of not doing so.