Dual Meter Panel Installation with Sub-Panels and Solar—Powering the Main Home & ADU the Right Way

📍 Project photos here

🔗 Visit: www.francopower.com

Why It Matters

As Accessory Dwelling Units (ADUs) gain popularity for rental income, family housing, and multi-generational living, the electrical systems need to evolve to ensure safe and independent operation. This is where panel installation plays a crucial role—allowing the main home and ADU to operate separately while sharing the same utility feed.

Franco Power recently completed a full panel upgrade that included:

• A 400A dual meter main panel

• (2) 200A sub-panels (main + ADU)

• A new 8kW solar grid-tied system for the ADU

  
  

This is a model project for homeowners looking to expand their property without sacrificing safety, efficiency, or code compliance.

Project Narrative

The client wanted their ADU to have its own meter for tracking usage and billing independently. This required upgrading the entire service entrance and tying in solar power for green energy efficiency.

We began by removing the outdated electrical panel, replacing it with a modern 400-amp dual meter combo panel, and wiring each structure to its own 200A sub-panel. This not only adds resilience and simplicity—it ensures both units can operate independently with properly balanced loads.

Though we didn’t capture the solar portion in photos, we also installed and grid-tied an 8kW PV system using microinverters and combiner boxes, which will help offset energy use for the ADU.

Step-by-Step Panel Upgrade Breakdown

1. Service Load Calculation – Evaluated combined power demand of both homes, factoring in HVAC, kitchen, and solar backfeed.

2. Old Panel Removal – De-energized service and safely removed the original panel and breakers.

3. Dual Meter Panel Install – Mounted and secured the 400A combo panel, with individual feeders to the sub-panels.

4. ADU Sub-Panel Wiring – Routed dedicated circuits for the ADU kitchen, HVAC, laundry, and EV-readiness.

5. Solar System Integration – Installed rooftop solar on the ADU, connected through a dedicated breaker, and grid-tied per utility spec.

   
   

Why This Helps

• Makes the property solar-ready and energy-efficient

• Keeps the ADU code-compliant and easily billable

• Prepares the home for EV charging and future upgrades

• Adds real value and flexibility to a modern family home

  
  

Expert Insight

“A dual meter setup with sub-panels allows landlords to legally sub-meter tenants while simplifying maintenance. It’s also required in many jurisdictions for ADUs.” — California Building Standards Commission

📞 Thinking about upgrading your home’s panel or adding an ADU? Contact the experts at www.francopower.com to make your upgrade smooth and future-proof.