How to Wire a 200 Amp Subpanel for Your Garage

How to Wire a 200 Amp Subpanel for Your Garage


Adding a 200 amp subpanel to your garage can provide the extra power needed to run larger tools and appliances like welders, air compressors, heaters, etc. Wiring a subpanel is not extremely difficult, but does require following proper safety precautions and electrical codes. In this guide I will walk through the complete process of wiring a 200 amp subpanel for a garage from start to finish.

Safety Precautions

When working with electricity, safety should always be the top priority. Here are some key safety tips to follow when wiring a subpanel:

Step 1: Choose a Location

When selecting where to mount the subpanel, consider the following:

Also check that there are no obstructions like ducts or pipes where you plan to mount the subpanel.

Step 2: Select a Subpanel

For a garage, I recommend choosing a 200 amp feed-through subpanel like those made by Square D or Eaton. Key features to look for include:

Step 3: Install the Conduit

Rigid metal conduit is recommended for subpanels as it provides the most protection. Determine the route the conduit will take from the main panel to the subpanel. Then:

Size the conduit for the wire gauge that will be used (see next step).

Step 4: Pull and Connect the Wires

For a 200 amp subpanel, you will need:

Use wire lube to pull the wires through the conduit without damaging insulation. Leave at least 8 extra inches of wire. Then connect the wires:

Ensure wires are tightly secured with no copper exposed.

Step 5: Bonding and Grounding

Proper bonding and grounding is critical for safety. This involves:

Use 6 AWG copper wire and proper ground clamps for these connections.

Step 6: Mount and Connect the Subpanel

You're now ready to permanently install the subpanel:

Step 7: Add Breakers and Label

The subpanel is now ready to be powered up after:

With the cover secured, you can switch the main breaker on to energize the subpanel.


Adding a new 200 amp subpanel involves careful planning, attention to safety, and adherence to electrical code requirements. Taking a methodical approach and double checking your work ensures a safe, successful installation. The subpanel provides the capacity to handle larger electrical loads, allowing you to get more use and enjoyment from your garage.