Okay, I understand the situation. You're trying to adapt a Talon 9817-9526 meter socket, originally designed for 3-phase, to accept a 600A single-phase residential service fed by two sets of 4/0 triplex aluminum conductors, and distribute that power to three 200A panels.

Disclaimer

Electrical work is inherently dangerous and should only be performed by qualified, licensed electricians who are familiar with local codes and regulations. This information is for informational purposes only and should not be considered a substitute for professional advice.Here's a breakdown of the key considerations and how you'd likely approach this conversion, based on standard practices, while highlighting the potential challenges and areas for careful attention:

Understanding the Challenges Meter Socket Compatibility

The Talon 9817-9526 meter socket is generally designed for 3-phase configurations. Modifying it for single-phase could present issues with how the meter connects and functions.

Current Capacity

Even though you are wiring 2 sets of 4/0 Aluminum, the termination may not be rated for 600amps with this small of wire.

Neutral and Grounding

Careful attention must be paid to the neutral and grounding connections to ensure safety and proper operation.

Utility Approval

This entire process requires approval from your power provider. They likely have specific requirements for single-phase conversions of 3-phase equipment. Do not proceed without their explicit sign-off and inspection criteria.

Assumptions and Initial Approach

Based on your description, here's the likely approach, assuming the power provider has allowed it, along with critical points to verify:1. A and C Phase Usage

You are correct with the fact that the "B" phase is not needed/used when converting from 3 phase to single phase using 2 phases. In this setup with high legs only 1 phase to neutral is 208V, this is not the case when you are using A phase and C phase in a single phase service.2.

Line Conductors (4/0 Aluminum)

This is the most problematic aspect you've highlighted. While 4/0 Aluminum is commonly used for 200A service, running parallel sets for 600A may be insufficient, especially given the termination limitations. This is where you need to VERY carefully verify ampacity and termination ratings.



NEC Ampacity

4/0 Aluminum (THHN/THHW/XHHW) is typically rated around 200 amps in free air and lower if run in conduit with other conductors. Two sets might get you close to 600A, but there are derating factors to consider.

Termination Ratings

This is the BIGGEST concern. The lugs in the meter socket, the breaker lugs in the panels, and any other termination points MUST be rated for the wire size and the continuous current. Most lugs are not rated for 300A each (half of the 600A). You may need to use listed and labeled tap connectors to join multiple smaller conductors to the main lugs.3.

Neutral Connection

The neutral conductor must be sized appropriately for the expected unbalanced load. In a residential setting with multiple 200A panels, the neutral is critical. Again, termination ratings are vital.4.

Grounding

The grounding electrode conductor (GEC) connects the service equipment to the grounding electrode system (ground rods, water pipe, etc.). It needs to be properly sized according to the NEC (National Electrical Code).5.

Meter Connection

This is the key. The meter socket needs to be wired so that the meter correctly measures the single-phase current. This might involve connecting the A and C phases to the appropriate terminals on the meter and leaving the B phase terminal unused. This is absolutely a point of coordination with the utility.6.

Load Balancing

Distribute the loads as evenly as possible across the three 200A panels to minimize neutral current and voltage imbalances.

Key Steps to Take1.

Mandatory Power Provider Consultation

This is paramount. You must have a detailed conversation with the utility about their specific requirements for this conversion. Get it in writing.2.

Load Calculation

Perform a thorough load calculation for the entire residence to determine the actual maximum demand. This helps verify the adequacy of the 600A service and conductor sizing.3.

Ampacity Verification

Consult the NEC (Table 310.16 and related sections) and other relevant code sections to determine the allowable ampacity of the 4/0 aluminum conductors in your specific installation conditions. Factor in conduit fill, ambient temperature, and other derating factors.
4.

Termination Evaluation

Critically examine the termination lugs in the meter socket, the panels, and any other connection points. Verify that they are rated for the wire size and current they will be carrying. This is often the weak link. If necessary, use appropriately sized and rated tap connectors.5.

Grounding Review

Ensure that the grounding electrode conductor and bonding jumpers are sized correctly according to the NEC.6.

Inspect and Test

Once the installation is complete, have a qualified electrical inspector verify the work to ensure it meets all applicable codes and standards.

Questions for the Utility What are your specific requirements for converting a 3-phase meter socket to single-phase service? Do you approve the use of 4/0 aluminum conductors for a 600A service? What meter wiring configuration do you require for single-phase metering? Will you provide a diagram or instructions for the meter socket wiring?

Important Considerations

Code Compliance

Ensure that all work complies with the latest edition of the NEC and any applicable local codes.

Safety

Always de-energize circuits before working on them. Use appropriate personal protective equipment (PPE).

Professional Help

If you are not a qualified electrician, hire one. Electrical work can be dangerous, and mistakes can lead to serious injury or property damage.

In Summary*Converting a 3-phase meter socket to single-phase is possible, but it requires careful planning, attention to detail, and, most importantly, close coordination with the power provider. The most critical aspect is to ensure that the conductors and terminations are adequately sized and rated for the intended load. Flag for review