# 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.

## How To Hook Up a Generator to the House Panel Using a Circuit Breaker Interlock Kit for Backup Power

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with my online Video Course:
Basic Home Electrical Wiring by Example

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 in 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.

The following may also be helpful for you:

## Dave's Guide to Home Electrical Wiring:

» 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, Handy Women, 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.

## Learn more about Home Electrical Wiring with my Online Video Course:Basic Home Electrical Wiring by Example

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

## The Safest Way to Test Electrical Devices and Identify Electric Wires!

The Non-Contact Electrical Tester
This is a testing tool that I have had in my personal electrical tool pouch for years, and is the first test tool I grab to help identify electrical wiring. It is a Non-contact tester that I use to easily Detect Voltage in Cables, Cords, Circuit Breakers, Lighting Fixtures, Switches, Outlets and Wires. Simply insert the end of the tester into an outlet, lamp socket, or hold the end of the tester against the wire you wish to test. Very handy and easy to use.

## The Quickest Way to Check for Faulty Electrical Wiring!

The Plug-In Outlet Tester
This is the first tool I grab to troubleshoot a problem with outlet circuit wiring. This popular tester is also used by most inspectors to test for power and check the polarity of circuit wiring.
It detects probable improper wiring conditions in standard 110-125 VAC outlets Provides 6 probable wiring conditions that are quick and easy to read for ultimate efficiency Lights indicate if wiring is correct and indicator light chart is included Tests standard 3-wire outlets UL Listed Light indicates if wiring is incorrect Very handy and easy to use.

## Strip Off Wire Insulation without Nicking and Damaging the Electric Wire!

The Wire Stripper and Wire Cutter
My absolute favorite wire stripping tool that I have had in my personal electrical tool pouch for years, and this is the tool I use to safely strip electrical wires.
This handy tool has multiple uses:
The wire gauges are shown on the side of the tool so you know which slot to use for stripping insulation.
The end of the tool can be used to grip and bend wire which is handy for attaching wire onto the screw terminals of switches and outlets..

The wire stripper will work on both solid and stranded wire. This tool is Very Handy and Easy to Use.

 More articles about Electrical Wiring, Garage Sub-Panel and Home Electrical Wiring: « Previous Next » Rewiring a Wall Switch for a Light Fixture Hot Tub Circuit Ground Wire

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.

2. 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.