Want to run a Sub Panel (or second panel) Main panel Full

As the title says, we have a 100A main coming into the house. We need another 100A panel for some servers, however there are no open spots in our main panel.

Our electrician mentioned instead of running a subpanel, he can run a second panel off of the main line.

Is this something that would pass inspection. He has been an electrician for some time but I’m wondering if he is being lazy?

What is the proper way to add a 100A panel in a location about 10 feet from the original.

  1. Run conduit along the ouside of the house from the main line (after the meter?) to a second main panel. They are both outside panels.

  2. Upgrade the main to a larger panel (200A?) to have more open spots for a 100A breaker for the sub panel?

This is in northern California.


Upgrade the 100 amp panel and you won’t need the sub-panel.

Have you done a load calculation to see if 100 amps is enough ?

The best solution is to upgrade the panel to 200 amps. Don’t forget to check and see if you need to also upgrade the service entry as well, many times people forget that. Add another $200 - $400 for that depending on the distance and difficulty.

A second panel (if done correctly) will not be a defect in an inspection, but thinking forward, more of a band-aid.