Wire Size for a Home Electrical Service Panel

By Dave Rongey - Summary:

How to Size Wire for an Electrical Service Panel: What kind of wires do I need to get power to my home?

Wiring an Electrical Service Panel

Electrical Question: What kind of wires do I need to get power to my home?

Project #1: Underground Electrical Service to a New Home

This Electrical Panel question came from: Bill, a Homeowner from Saratoga, California.

 Project #2: Electrical Service to a Mobile Home

This electrical wiring question came from Madison , in Vidalia, Georgia.

Dave’s Reply:
Thanks for your electrical wiring questions Bill and Vidalia.

How to Size Wire for an Electrical Service Panel

main electric panel

Application: Installing a Main Electric Service Panel
Skill Level: Advanced – Best installed by a Licensed Electrical Contractor.
Tools Required: Electricians pouch of hand tools and the various power tools necessary for the specific method of electrical service installation.
Estimated Time: Depends on the type of panel, the location, and available access to the project area.
Precaution: This is an extensive project. Working in an electric panel has possible electric arc flash hazards and should be performed by a Licensed Electrical Contractor.
Notice: Installing an Electrical Service Panel should be done according to local and national electrical codes with a permit and be inspected.

Planning an Electrical Service for a Home

In the projects mentioned above there are factors that will determine the type and size of the electrical service to the home, first let’s start with the basics:

The Electrical Service

Terminology and Clarification

Overhead or Underground Service

Factors for Sizing the Electrical Service

Residential Electrical Load Calculator

  • Electrical Load Calculator

    • The Electrical Load Calculator is a fully functional online and Interactive tool that will assist you with accurate panel load calculations.
    • The Residential Electrical Load Calculator is Pre-Loaded with electrical information for you to chose for typical electrical loads in the home.
    • General Electrical Load Requirements, Appliances and Motor Loads, Heating and Air Conditioning equipment.
    • Sizing Wire for a Panel: Voltage Drop Calculator

More about the Home Electrical Service Panel


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Electrical Codes for Home Electrical Wiring
....and much more.

» Click here to learn more about Home Electrical Wiring «
  repair electrical wiring  

Be Careful and Be Safe - Never Work on Energized Circuits!
Consult your Local Building Department about Permits and Inspections for all projects.


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FAQs Frequently Asked Questions and Comments

2 Responses to “Wire Size for a Home Electrical Service Panel”
  1. Dave Rongey says:

    Hi Rich,
    Water corrosion inside a panel can cause extensive damage to the electrical components, so it was good to have the leak repaired and the circuit breakers replaced.
    The ground system of the main service panel is extremely important and must not be compromised. Therefore, if the ground bus has been corroded then it should be cleaned and repaired, or replaced.
    VERY IMPORTANT: The ground system of a panel should never be serviced or disconnected while the main electric service power is on. All methods and components of the ground system must conform to applicable electrical codes and compatible with the electric service panel. This work is best performed by a qualified electrician or licensed electrical contractor.
    Be Safe,

  2. rich says:

    I recently had to go into my 200 amp service panel and noticed that water was coming in through the main service cable. I had that leak fixed, but I noticed that the ground bus and two breakers were corroded. I replaced the breakers. Must I also replace the ground bus? There were no service interruptions and all seems to be doing fine.


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