Electrical Wiring for a Garage Workshop

By Dave Rongey - Summary:

Installing an Electric Panel for a Detached Garage: Electric Codes for a Detached Garage Panel, Can I use a Main Lug Only Electric Panel Load Center for a detached garage?

Garage and Workshop Electrical Wiring

Electrical Question: Can I use a Main Lug Only Electric Panel Load Center for a detached garage?

  • I intend to electrify a detached garage, which is about 60 ft. from the house panel.
  • The Power needs will be convenience outlets and lights for a workshop.
  • The project and circuits to be installed are the following:
    • I will use two 30Amp circuits, 3 wire + equipment ground, #10 wire, in 3/4″ underground PVC conduit to provide the power to the garage.
    • I plan to install a 30Amp load center in the garage with two 20Amp circuit breakers.
  • Can I use an MLO or Main Lug Only Load Center or do I need a Main Disconnect as well?

This electrical question came from: Jim, a Property Manager from Urbana, Illinois.

Dave’s Reply:
Thanks for your electrical question Jim.

Installing an Electric Panel for a Detached Garage

Application: Installing an Electric Panel for a Garage or Workshop.
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 shock and arc flash hazards and should be performed by a Certified Electrician or Licensed Electrical Contractor.
Notice: Installing an Electrical Panel should be done according to local and national electrical codes with a permit and be inspected.

Electric Codes for a Detached Garage Panel

Jim, because the garage is detached it would be best to have a main disconnect, however please see the following electrical codes that will apply to your question.

  • The panel may not have more than 6 circuit breakers.
  • If the number of circuit breakers are more than 6 then a main disconnect is required.
    • NEC Electrical Code Reference articles 225.31, 225.32, 225.33, 225.36.

More about Wiring a Garage or Workshop

Electrical Wiring Codes
Electrical Code

  • Home Electrical Codes

  • Electrical Code Directory covering  electrical boxes, electrical circuit, electrical code outlets,  electrical grounding, electrical services, electrical underground, and electrical wiring methods.

Garage Electrical Wiring

  • 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.

Electric panel

  • 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.

Electrical Circuits

  • 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.

Circuit Breakers

  • Electrical Wiring Protection using Circuit Breakers
  • A guide to home electrical circuit breakers and how they work to protect your electrical wiring.
  • When properly installed, your home electrical wiring is protected by a circuit protection device.

Electrical Wire

  • 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.

Learn How to Wire it Right with my
Complete Guide to Home Electrical Wiring
Perfect for Homeowners, Students,
Handyman, Handywomen, and Electricians
Wiring GFCI Outlets
Wiring Home Electrical Circuits
120 Volt and 240 Volt Outlet Circuits
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
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.


Click the banner to Ask a Detailed Electrical Question and get an Instant Reply:
electrical question

FAQs Frequently Asked Questions and Comments

2 Responses to “Electrical Wiring for a Garage Workshop”
  1. admin says:

    Excellent advice John,
    Thank you for your addition to this article. It is so very important to plan for any future circuits. The panel will be rated for a larger service, so it would be well to take advantage of that and run a larger feeder to provide more amperage.

  2. John Engel says:

    You will need a main disconnect for the load center or panel you will install. The easy way to do this is with a convertible Main lug Main breaker setup. This is more expensive than putting in a 30 Amp load center, but it is safer and will be code compliant. Why are you just putting 2 20 Amp circuits in the garage? You are not leaving any room for upgrading the amperage. I would install a 60 Amp circuit to the garage that should take care of your needs. The #6 AWG wire will cost you about .88 a foot, but you will have enough amperage for an electric heater if you use your garage in the winter. Hope this helps you.


If you are asking a Quick Question please make sure it is about This TOPIC:
“Electrical Wiring for a Garage Workshop”

Comments Posted here are Open for Quality Discussion and Participation.