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The electrical panel in modern electrical systems also has a main breaker in addition to the individual circuit breakers. The main breaker allows you to shut off power to the entire building whenever needed, such as when performing major work on the electrical system. It also provides an additional safety mechanism in case you ever experience major electrical problems, such as the electrical panel overheating or smoking. If you ever experience an issue with an individual circuit, you can use the main breaker to turn the power off in case you can’t find the right individual breaker. While most electrical panels have a main breaker, not all of them do.
The Role of Electrical Panels and Circuit Breakers
While there are several different types of electrical panels, they all serve the same role, which is distributing power to all the building’s circuits. Each circuit is controlled by a breaker, allowing you to shut off the power to an individual circuit as needed. Circuit breakers are also an essential safety mechanism. If a circuit ever becomes overloaded, the breaker will instantly trip, stopping the flow of power. An overload is when the electrical current flowing through a circuit is higher than what the circuit can safely handle. Overloads can be extremely dangerous, as they result in wires heating up and potentially catching on fire.
Why Some Electrical Panels Don’t Have a Main Breaker
Every single-family dwelling built from the 1980s onward has a main breaker on the main electrical panel, as this is a requirement under the National Electrical Code (NEC). Nonetheless, there are some electrical panels that either don’t need or aren’t required to have a main breaker. Specifically, this applies to subpanels, electrical panels in multi-unit dwellings, and main panels in older homes that were built before the NEC required a main breaker.
The Use of Subpanels
A subpanel is a smaller secondary panel that only distributes power to a few circuits in one part of a building or to a structure like a detached garage. It’s common to use a subpanel when putting an addition onto a building, as it makes the process of wiring the addition easier and cheaper compared to connecting all the new circuits to the main panel.
There are times when a subpanel will have a main breaker, but it’s not a requirement in most cases. The exception is for a subpanel in a detached garage or other building, as this situation does require there to be a disconnect or shutoff directly in or outside the structure. The reason that a main breaker usually isn’t required for a subpanel is that the wire running from the subpanel is connected to a circuit breaker in the main panel. That means you can just shut that breaker off to turn the power off to the subpanel. The main breaker in the main panel also serves as a disconnect for the subpanel.
Considering Multi-Unit Dwellings
The electrical panel in multi-unit dwellings like apartments may not have its own main breaker. All the units in this type of building are typically connected to the same electrical system. That means the panel in each unit is basically the same as a subpanel. All these smaller panels are then connected to a main panel with a main breaker somewhere else in the building, allowing staff to shut off the power to the entire building if needed. Staff can also shut off the power to each individual unit from this main panel.
The Use of Split-Bus Panels
This type of panel is becoming quite rare, but you still occasionally find them in buildings built between the 1960s and 1970s that haven’t had their original panel upgraded. Modern electrical panels have a single bus bar. A bus bar is a piece of metal inside the panel that the power flows through. Each circuit breaker is connected to the bus bar, meaning it’s responsible for distributing power to all the circuits. When you shut off the main breaker, what you’re doing is blocking power from continuing to flow through the bus bar.
Split-bus panels have two bus bars and usually aren’t required to have a main breaker. Instead, they can have up to six total breakers that are used to shut off power to the entire electrical system. In a split-bus panel, the top bar has six circuits and breakers. The top bus bar distributes electricity to all the higher-demand circuits, which usually includes the building’s major appliances. The lower bus bar contains the circuits that supply power to the standard circuits that control the building’s lighting and outlets. The sixth circuit in the top bus bar is wired directly to the bottom bus bar, allowing you to use that breaker to shut off power to most of the building. However, you still must shut off the remaining breakers in the top bar to shut off power to the entire building.
This type of setup is still allowed if the panel conforms to the “six throw” rule. This rule stipulates that it requires no more than six breakers to shut off power to the entire building. You can easily tell if you have a split-bus panel, as it will have one section with only six breakers and an additional section with additional breakers. You can also tell just because it doesn’t have a main breaker.
Is It Necessary to Replace an Electrical Panel if It Doesn’t Have a Main Breaker?
If you have an old electrical panel that doesn’t meet the current code requirement of having a main disconnect or breaker, you’re not legally required to replace it in most situations. The only time you are required is when performing an extensive renovation or doing major electrical upgrades, such as rewiring much of the building. Nonetheless, we would recommend upgrading to a new panel if the existing one doesn’t have a main disconnect. The main reason is that any main panel that doesn’t have one is extremely outdated and could pose a major safety hazard.
Electrical panels are generally only meant to last for 25 to 30 years. After this point, there’s an increased risk of potentially serious issues like overloads and arc faults due to deteriorating wiring in the panel and worn-out circuit breakers. That means upgrading to a new panel will make your electrical system much safer. It can also lower your electricity bills, as new panels are able to distribute power much more efficiently to cut down on waste. You may even get a discount on your homeowner’s insurance if you upgrade your panel. This upgrade can make your home safer and lessen the chances of major issues like electrical fires.
When you need an experienced residential or commercial electrician in Canton, OH, [company_name] is the company to call. We specialize in all types of electrical services, from electrical panel upgrades to repairs and installations. If you’re experiencing any issues with your electrical system or are unsure if you should replace your electrical panel, contact [company_name] for a professional inspection.
