Panel load refers to the total amount of electrical energy that can be drawn from a single electrical panel. It represents the sum of all electrical current used by each appliance within a home or commercial building. In the United States (US), panel load is typically measured in amperes, or amps.
Every item that relies on electricity draws power from one or more circuits within a panel. Large appliances like heating systems or dryers often have their own dedicated circuit to handle the larger load these items require. Smaller appliances, lighting and other electrical needs often share a circuit, as they typically draw smaller levels of electricity. By adding up the total amps, or current, used by each of these items, one can determine total panel load.
Each electrical panel is rated for a specific load based on factors such as design, wiring and safety features. For example, a panel in a single-family home may be rated for 200 amps, while commercial facilities may have panels rated much higher. The panel rating lets users know how much total electricity can safely be drawn from the panel. Trying to draw power beyond this rating can cause circuits to fail, and may lead to fires and other serious risks.
Municipal building codes determine the total required load for electrical panels within a facility. Builders must install panels capable of safely handing this load. Homeowners who wish to increase the available electrical current within the home must upgrade the panel to meet these needs. This type of work is very complex and dangerous, and should only be handled by a trained professional. Improper panel upgrades can lead to system failures, poor performance or even electrical fires.
In most cases, the panel must be designed to handle more than the rated level of electricity. For example, a panel rated at 200 amps may be required by code to handle power surges up to 250 amps. This protects residents from damage during a power surge, and also keeps users safe if too many electrical items are used at one time. Local and national electrical codes determine how much excess power the panel should be designed to handle.
In some areas, panel load may be rated in voltage-amperes, or VA units. In this type of application, users should first calculate total panel load in amps. By multiplying total amps by the standard 120 volt power supply used in the US, users can calculate panel load in VA units.