Residential Load Center Basics

Main breaker load centers are typically used as an electrical service entrance. In these setups, the utility’s incoming power cables connect directly to the main breaker, which then distributes electricity throughout the load center and its branch circuits. The main breaker also functions as a primary disconnect and provides overcurrent protection for the entire panel. This powers the whole house.

Main lug load centers are typically installed downstream from a main breaker panel and are commonly referred to as sub panels. Lug load centers connect to the incoming power cables directly to lugs attached to the bus bar, without passing through a main breaker. The "lugs" are terminals that are provided to connect the incoming line. In this case, the main disconnect and overcurrent protection functions must be provided by some other device upstream. Examples include an enclosed circuit breaker, a fusible switch, a circuit breaker in another load center, or a disconnect in a meter enclosure.

Of note, a convertible load center consists of a main lug load center that can be converted to a main breaker in the field.

A load center is the main electrical panel used in residential settings. It serves as the main breaker box where electricity from the utility company enters the home and is distributed throughout the entire residence.

A sub panel, or sub panel box, extends the functionality of the main load center by distributing power to a specific area or structure away from the main electrical panel. Often referred to as a small electrical panel, it is used to add circuit capacity, manage electrical loads in separate zones, or provide control for remote areas such as garages, workshops, or outbuildings.

A load center, or main electrical breaker panel, is ideal for standalone installations where no other main disconnect is present and is used for residential or dwelling applications.

A substation plays a critical role in the electrical power system by transforming and switching electricity to ensure a safe and efficient delivery from power plants to consumers. It serves as a connection point between high-voltage transmission lines and lower-voltage distribution networks. Substations are commonly used in industrial and commercial applications where high-voltage handling is required.

The size of the load center installed in a home depends on the total electrical load and the household's energy consumption requirements. ABB provides load centers in 40 Amp, 70 Amp, 100 Amp, 150 Amp, 200 Amp, and 225 Amp options. A licensed electrician will assess the specific needs of the dwelling by evaluating appliances, lighting, EV chargers, and other factors. They will calculate the total electrical demand of all connected circuits and devices to ensure it stays within the panel’s amperage rating, while also accounting for future expansion and safety considerations.

Main breaker load centers are typically used as the primary panel in a home, while main lug load centers are used as sub panels for applications like garages, workshops, or outdoor spaces requiring electricity. When used as the primary panel in a home, main breaker load centers provide a means of primary disconnect for the panel. The 2020 NEC code stipulates that a means of outdoor emergency disconnect must be in place, and this can be achieved with an outdoor main breaker load center. Main lug load centers are often smaller and more cost-effective than main breaker load centers. They can also be installed as the primary panel in a smaller home. In order to satisfy code requirements, they are installed downstream from a means of outdoor emergency disconnect. For example, an outdoor main breaker load center, an outdoor meter combo, or an outdoor enclosed circuit breaker will be installed ahead of a main lug load center. Considerations around size, cost, local code, and amperage requirements will come into play when selecting a main breaker or main lug load center.

Yes, ABB offers residential surge protection to safeguard against power surges and lightning strikes. ABB offers two types of whole-home surge protection. Both offerings are brand agnostic, meaning they can be used with any load center brand. These devices can be installed in load centers and sub panel locations. The THOMESURGE and THQLSURGE2 SPDs provide surge protection for the entire panel and all attached loads. Plus, they comply with NEC®2023.

The number of circuits a load center can handle varies by model. ABB residential load centers can handle anywhere from 2 to 60 1-inch spaces for the circuit breakers. ABB also sells options for space-saving electrical tandem and quad circuit breakers designed to provide two separate circuits within a one-inch breaker.

Plug-on neutral load centers simplify the installation of arc fault and ground fault circuit breakers (AFCIs and GFCIs) by eliminating the need for pigtail connections. ABB has a ReliaLock plug-on neutral bar to facilitate easy and fast installation.

Outdoor load centers need to be weatherproof and rated for outdoor use (NEMA 3R), while indoor load centers (rated NEMA 1) are typically installed in basements, garages, or utility rooms.