# Add a Panel to an Existing Electrical Panel

 How can I wire a shed panel to a garage panel? How to Calculate the Electric Circuit Load of a Sub Panel, Understanding the Circuit Capacity of a Garage Sub Panel.

Wiring to an Electric Panel
Electrical Question: How can I wire a shed panel to a garage panel?

• I have a sub-panel in my garage.
• The garage panel has three 15 amp circuits and one 20 amp circuit in it.
• Can I use this panel to power another panel for my shed which is 15 feet away?

Any help greatly appreciated.
I know how to wire it but not sure its a safe and good idea.

This electrical question came from: Ellis, a Homeowner from Rixford, Pennsylvania.
See more about Home Wiring for Pennsylvania

Thanks for your Electrical Wiring Question Ellis.

## How to Calculate the Electric Circuit Load of a Sub Panel

Application: Installing a Circuit to a Garage Sub Panel.
Skill Level: Intermediate to Advanced – Best installed by a Licensed Electrical Contractor.
Tools Required: Basic Electricians Pouch Hand Tools, electric drill,  auger bits and extension cord.
Estimated Time: Depends on personal level experience, ability to work with tools and install electrical circuit wiring.
Precaution: Identify the panel power source, turn it OFF and Tag it with a Note before working with the new circuit  wiring.
Notice: Installing additional circuits and electrical wiring should be done according to local and national electrical codes with a permit and be inspected.

### Understanding the Circuit Capacity of a Garage Sub Panel

• In order to add a circuit to your garage sub panel that would provide power to a sub-panel for your shed one would first need to know the amperage size of the garage sub panel.
• Determine the proposed electrical circuit loads that will be installed in the shed.
• Will these new circuit be 120 volts only or will there be any 240 volt circuits, and what will the amperage load of these circuits actually be so the size of the sub-panel can be determined for the shed.
• The existing 15 amp and 20 amp circuit loads which are being supplied by the garage sub panel must be evaluated to determine the actual amount of amperage load that is being placed on the garage sub panel.
• Once all this electrical load information is obtained and calculated then it could be determined if the garage sub-panel actually can handle the additional load for the proposed shed sub-panel and the additional electrical loads.

Circuit Wiring

• ### Sub-Panel Electrical Wiring for the Home

• Electrical Sub-Panel wiring considerations for the home complete with pictures. Careful planning for your Sub-Panel with immediate and future load considerations will help you understand how to size your Sub-Panel. This information will help as you consider a Sub-Panel and its size.
• ### House Wiring Circuits and Circuit Breakers

• This article looks at common 120 volt and 240 volt house wiring circuits and the circuit breakers that are installed identifying the types and amperage sizes used in most homes.
• ### Electric Circuit Listing

• The size of the home electrical service panel is designed by calculating the square footage of the home and factoring in the code requirements for the electrical circuits that are required.

### Electrical Wire for the Home

Complete listing of electrical wire types and parts used for home projects with electrical code information serves as selection guidelines.

### Garage Electrical Wiring

Garage electrical wiring diagram and considerations for wiring garage circuits, complete with pictures. Careful planning for your garage with immediate and future equipment considerations will help you understand how to size your electrical circuit requirements. This information will help as an garage electrical wiring guide.

 » You Can Avoid Costly Mistakes! « Here's How to Do It: Wire It Right with the help of my Illustrated Wiring Book Great for any Home Wiring Project.

## Complete Guide to Home Electrical Wiring

Perfect for Homeowners, Students,
Handyman, Handywomen, and Electricians
Includes:
Wiring GFCI Outlets
Wiring Home Electric Circuits
120 Volt and 240 Volt Outlet Circuits
Wiring Light Switches
Wiring 3-Wire and 4-Wire Electric Range
Wiring 3-Wire and 4-Wire Dryer Cord and Dryer Outlet
How to Troubleshoot and Repair Electrical Wiring
Wiring Methods for Upgrading Electrical Wiring
NEC Codes for Home Electrical Wiring
....and much more.

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

2 Responses to “Add a Panel to an Existing Electrical Panel”
1. Forrest BRown says:

If I understand the question correctly, this would be a sub sub panel from a sub panel fed from a main panel. The capacity of the entire system needs to be evaluated. The following is a quote from your sub panel link:

“Important Factor: Find out if the Main Service or the Panel that will supply the Sub-Panel Circuit have adequate Load Capacity and space for the needed circuit breaker.”

This would obviously include any panels fed from the sub panel.

I don’t want to sound pedantic, but I think it is worth noting.

• Dave Rongey says:

That is correct Forrest, the loads of the entire electrical system must be evaluated to understand if there is ample capacity for the proposed load to be added.