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Residential Panel & Feeder Load Calculator

Enter the loads connected to the panel being evaluated. The calculator applies the worksheet method shown in E1/E2 and reports the calculated load in VA and amperes at 240 volts.

1. Calculation scope

For a subpanel calculation, include only the floor-area and branch-circuit loads served by that subpanel, consistent with the scope of the worksheet. For a main-panel calculation, include the dwelling loads supplied by the main panel, including loads supplied through subpanels. Do not count the same load twice.

2. Appliance loads

Enter quantity and, where applicable, additional nameplate VA. The listed default VA values follow the source worksheet; replace them with actual nameplate values when available.

ApplianceDefault VA eachQuantityAdditional VACalculated VA

The 75% option is presented as a selectable worksheet assumption. Confirm that the selected appliances qualify for the applicable demand factor before using it.

3. Heating and cooling loads

Enter nameplate VA. The calculator uses the largest entered heating/cooling load, rather than adding mutually exclusive heating and cooling loads.

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4. Panel and feeder information

The conductor ampacity is calculated from the selected size, material, and temperature column. The check compares ampacity to the selected feeder overcurrent device rating, not merely to the calculated load.

Calculated results

General lighting load (3 VA/sq. ft.)6,000 VA
Small appliance + laundry loads4,500 VA
Appliance load before demand factor0 VA
Appliance load after demand factor0 VA
Demand-adjusted non-HVAC load8,000 VA
Largest heating / cooling load3,624 VA
Total calculated load11,624 VA
Calculated feeder / panel load48.43 A
Important: This is a worksheet aid, not an approved load calculation or conductor-sizing determination. The source workbook combines CEC 220.83(A) load-calculation language with heating/cooling inputs labeled 220.82(C). Verify the applicable method, demand factors, existing-load treatment, conductor ampacity, terminal temperature limitations, adjustment/correction factors, equipment ratings, and adopted code edition for the actual project. A breaker rating, panel bus rating, and conductor ampacity are separate checks.

Building Standards for Electric Systems

Scope Examples: Installation, repair, or renovation of residential electrical systems and appliances. This may include:

  • Installing or upgrading electrical service panels and sub-panels.
  • Wiring for lighting, outlets, switches, and dedicated circuits for appliances.
  • Installing or replacing electrical systems for HVAC, water heaters, and other electrical appliances.
  • Adding outdoor electrical features such as outlets, lighting, or electric vehicle chargers.

Title 24 is divided into specific parts addressing various aspects of construction. Key sections for electric systems include:

  1. California Electrical Code (CEC):

    • Governs all electrical installations, including wiring, electrical panels, circuits, and outlets.
    • Includes requirements for circuit breakers, grounding, wiring methods, and system protection.
    • Regulates installations for major appliances such as ranges, dryers, and water heaters.

  2. California Building Code (CBC):

    • Applies to the structural requirements for housing electrical systems and ensuring safety from fire hazards related to electrical installations.

  3. California Residential Code (CRC):

    • Provides standards for electrical systems in one- and two-family dwellings.
    • Includes rules for electrical access, outlet placement, lighting, and emergency systems such as backup power.

  4. California Energy Code:

    • Enforces energy efficiency standards for lighting, electrical systems, and appliances, including requirements for energy-efficient lighting and electrical equipment.
    • Promotes the use of smart home systems for energy savings.

  5. California Plumbing Code (CPC):

    • While primarily focused on plumbing systems, it may also address electrical concerns related to water heating systems and pool/spa equipment.