Okay, let's break down this situation and explore the options. You're navigating the intricacies of service upgrades, 3-wire circuits, and disconnect requirements. Your goal is to save some money, but compliance and safety are paramount.Here's a breakdown of the issues and potential solutions

Understanding the Problem:
Existing 3-Wire Range Circuit

This is the crux of the issue. A 3-wire circuit means the neutral conductor is also acting as the grounding conductor. This violates current code for new installations and complicates the service upgrade because you cannot use the meter/disconnect as a service disconnect.

Meter/Disconnect Combo Unit (Square D HOM)

You want to use the Square D HOM meter/disconnect with the small breaker space to save money.

Code Requirements

The 2020 NEC (and subsequent editions) require separate neutral and grounding conductors for services and feeders.

Service Disconnect Location

NEC 230.70 requires a service disconnect to be inside or outside the building. The main challenge is keeping the first disconnect at the meter enclosure while also dealing with the range.

Why Your Original Plan Doesn't Work Now (Due to the 3-Wire Range)


Meter Disconnect as Service Disconnect = No Go

If you used the meter/disconnect as the service disconnect, you would need a 4-wire feed from there to your main panel inside the house. Because of the 3-wire range, any grounding and bonding needed for service equipment

must take place at the service disconnect (where the neutral and ground are bonded). Since you can't upgrade the range, you can't use the meter disconnect as the main service disconnect.

Possible Solutions (and their pros/cons)


(Recommended) Upgrade the Range Circuit



How it works

Run a separate equipment grounding conductor (EGC) back to the new panel for the range. This involves running a new 4-wire circuit or adding a separate grounding conductor from the panel to the range receptacle and changing the receptacle and cord to a 4-prong configuration.

Pros

Completely code-compliant. Safer: Provides a dedicated grounding path for the range. Allows the meter/disconnect to function as the service disconnect (if you choose this config.)

Cons

Most costly solution in terms of materials and labor if running a new circuit is difficult.2.

(Your Idea, but with Tweaks) Meter Enclosure as Emergency Disconnect / MBP as Service Disconnect



How it works

Install the Square D HOM at the meter. Mark it as an emergency disconnect (or "feed-through disconnect"). Run a 3-wire feed from the HOM to a new Main Breaker Panel (MBP) inside the house. Bond the neutral and ground only in the MBP.

Pros

Potentially saves money compared to replacing the range circuit. Technically compliant (with careful execution).

Cons

Potential for confusion and misinterpretation during future work. The available breaker spaces in the HOM are effectively wasted. More complex wiring scenario.

Here's how to make this option work (with some considerations)



Clear Labeling is Critical

The Square D HOM MUST be labeled very clearly as an emergency disconnect or "feed-through disconnect." It should be clearly stated that it is not the service disconnect.

MBP Bonding

The neutral and grounding conductors MUST be bonded only in the MBP inside the house. This is where the grounding electrode conductor (GEC) will also connect.

Overcurrent Protection

The 3-wire feeder conductors going from the Square D HOM to the MBP must be protected by an overcurrent device (breaker) in the Square D HOM that is sized appropriately for the ampacity of the conductors.

230.70 Compliance

This solution hinges on the fact that 230.70 requires the disconnect inside the building. The HOM would be considered an upstream "feed-through" disconnect, not the service disconnect as defined by code.

Important Considerations for Solution #2



Inspection

Be prepared to explain this setup to your electrical inspector. Have your code references ready.

Future Work

This setup will need to be very clearly documented for future electricians who may work on the system. Clear labeling is essential.

Safety

Ensure all connections are tight and properly insulated.

Alternative Meter Disconnect options1. A Meter enclosure only

If you truly wanted to save money, remove the Homeline meter disconect from the equation and install a meter enclosure instead. This would be the most cost effective way to achieve your goal.

Recommendation

While your idea could* work,

the best and safest option is to upgrade the range circuit to a 4-wire configuration. It provides a cleaner, more straightforward, and code-compliant solution. It avoids any potential confusion and ensures proper grounding for the range.If you're absolutely set on using the Square D HOM as an emergency disconnect, make sure you understand the requirements and are prepared to implement the solution meticulously.

Before you proceed, I strongly recommend consulting with a qualified electrician who can assess your specific situation and advise you on the best course of action. They can help you ensure compliance with local codes and regulations. Flag for review