A home’s main electrical panel is responsible for supplying the power coming into the house from the grid to all of the lights, outlets and appliances. That means it’s the central hub of the home’s entire electrical system. Knowing how your electrical panel works and what roles all of its components play is important for preventing potential power issues and electrical hazards.
It’s also key for ensuring you know what issues to watch for and what steps to take whenever a problem arises. That’s why we’ve created this guide to help explain everything you should know about your home’s electrical panel.
The Role an Electrical Panel Plays in Power Distribution
Electrical circuits are closed loops, meaning power continually flows through them in two directions. The power coming into a home from the grid flows into the electrical panel through the hot or live wire. Any excess power that isn’t immediately needed then flows directly back to the grid through the neutral wire.
Different parts of a house and different appliances are on different circuits, each of which connects to the electrical panel. When you turn your TV or anything else on, the electrical panel then starts sending power to whichever circuit that device or appliance is on through that circuit’s live wire. Excess power then again flows back to the panel through that circuit’s neutral wire.
The majority of a home’s circuits are also 120 volts. This includes all of the circuits for the lights and outlets. Many major appliances, including refrigerators, freezers, washing machines and dishwashers run on 120-volt power. However, some things like air conditioners, clothes dryers and stoves require 240-volt power and are always wired to a dedicated circuit that only supplies power to them.
To supply 240-volt power, these circuits require two live wires and two neutral wires instead of just one. When the appliance is running, power always flows to it from the electrical panel through both live wires and then back to the panel through both neutral wires.
The Components of an Electrical Panel Explained
Main electrical panels are sometimes also referred to as electrical service panels, breaker boxes. You’ll also occasionally hear the term fuse box. However, this term is outdated, as fuses were phased out when circuit breakers became the new standard. The term breaker box can also be a bit confusing, as the breaker box is just one part of an electrical panel.
Electrical panels consist of several components that all play a vital role in power distribution and/or safety. Most modern electrical panels consist of two sides—the circuit breaker side and the service side. The circuit breaker side is either open or has an access door or panel. The service side contains all of the wiring and is usually locked or otherwise closed, as it can only legally be accessed by a licensed electrician or the utility company.
Main Breaker
All modern main electrical panels have a main breaker, and the purpose of this breaker is to allow you to shut off the power to the entire home. Some older homes may have what’s known as a split-bus panel, which doesn’t have a main breaker. Instead, you need to switch off all of the breakers on the top bar in the panel to shut the power to the house off.
If you live in an apartment or condo, the electrical panel for your unit may not have a main breaker. That’s because it may instead be a sub-panel that’s wired to a main panel with a main breaker located elsewhere in the building.
Bus Bar
The bus bar is a thick piece of metal that’s responsible for distributing electricity to the individual circuits. It basically just provides a path for the electricity to travel from the panel into the circuit. Modern panels have a single bus bar, but split-bus panels have an upper and a lower bus bar. The upper bus bar contains the dedicated major-appliance circuits, while the lower bus bar supplies power to the rest of the circuits.
Neutral Bar
The neutral bar serves the same basic purpose as the bus bar, except that it provides the path for the returning current from the neutral wires to flow back out into the grid.
Ground Bar and Grounding Rod
Modern electrical circuits also have a ground wire in addition to the live wire and neutral wire. Grounding is another essential part of electrical safety, as it ensures electricity can be safely released into the ground in the event of an electrical fault that results in a power surge. When power gets redirected and flows through a circuit’s ground wire back to the electrical panel, it first flows through the ground bar in the panel and then out into the copper grounding rod that’s driven into the ground outside the house.
Circuit Breakers
The purpose of circuit breakers is to instantly stop power from continuing to flow in case of an issue, such as an overload or a short circuit. An overload is simply when you’re trying to draw more power than the circuit is meant to supply and exceeding its capacity. A short circuit occurs when a live wire touches a neutral wire, allowing the power to flow unrestricted and resulting in a major spike in voltage. Both of these issues can be equally dangerous and potentially result in a fire starting due to the wiring overheating.
Circuit breakers are designed to prevent this type of issue from happening. The way it works is that the breaker has either a metal strip or an electromagnet that will cause it to trip if the current exceeds the safe level. Circuit breakers also allow you to shut off the power to a circuit in case of a situation like an outlet that’s started smoking or whenever you need to do any work on the circuit.
How to Spot Signs With Your Electrical Panel
Knowing if you need to repair or replace your electrical panel is key to keeping your home and family safe. One thing to note is that electricians typically recommend replacing a home’s main electrical panel every 25-30 years. It’s also important to have your panel and electrical system inspected if you notice the panel feels hot, shows signs of rust and corrosion or starts making a loud buzzing, humming or crackling sound.
Having issues with different breakers that keep tripping is also a good sign of a wiring issue with your electrical panel. If just a single breaker keeps tripping, the issue usually lies with that breaker or that circuit.
For professional electrical services you can always count on, trust the experts at Anderson Heating, Cooling, Plumbing & Electric. We’ve been serving homeowners in Mentor, OH, and the Greater Cleveland area for more than four decades and can see to any and all of your electrical needs. From repairs and electrical panel upgrades to inspections, our team is ready to ensure your electrical system is safe and works the way you need it to. To schedule a service appointment or get answers to any questions you may have, contact Anderson Heating, Cooling, Plumbing & Electric today.
