Okay, let's break down the grounding electrode conductor (GEC) sizing, surge protection, and load center additions in your project. Since you're now under the 2020 NEC, you're correct that grounding electrode conductor sizing is crucial and has likely changed from the previous code cycle.1. Grounding Electrode Conductor (GEC) Sizing

This is the most critical aspect. NEC Article 250 covers grounding and bonding, and Table 250.66 is your key reference for sizing the GEC based on the size of the service entrance conductors.

The correct method is to size the GEC based on the LARGEST ungrounded (hot) service conductor. You stated that FPL brought in 4/0 Aluminum. Per Table 250.66: For 4/0 Aluminum, you need a #2 AWG Copper GEC or 1/0 AWG Aluminum GEC. The ground rods and the bonding of building steel also need to comply with the correct GEC sizing. Section 250.66(A) requires that the portion of the GEC that is the sole connection to one or more ground rods, ground plates, or concrete-encased electrodes need not be larger than #6 AWG copper. Section 250.64(F) requires that a bonding jumper to building steel must not be smaller than the GEC specified in Table 250.
66.

Therefore, based on the 4/0 Aluminum service entrance conductors, you will need the following minimums



To the Ground Plate (if still used)

#2 AWG Copper or 1/0 AWG Aluminum.

To the Ground Rods

#6 AWG Copper (maximum size required for connection to ground rods). You can use larger but it's not required by the NEC.

To Building Steel

#2 AWG Copper or 1/0 AWG Aluminum

Important Notes about the GEC



Continuous Run

The GEC should be a continuous run from the service equipment to the grounding electrode(s). Splices are generally not permitted (unless using irreversible compression connectors listed for the purpose).

Protection

The GEC needs to be protected from physical damage. If subject to physical damage, it needs to be installed in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor.

Aluminum vs. Copper

If using Aluminum, ensure that the termination lugs are rated and suitable for Aluminum conductors (AL/CU listed). Applying anti-oxidant paste will help prevent corrosion.

2. Surge ProtectionSince you're in the 2020 NEC, Article 230.67 requires surge protection on dwelling unit services. You mentioned having room in the meter center's 8/16 panel for a surge protective device (SPD). That's a great option.

Type SPD

The NEC requires a Type 1 or Type 2 SPD. Given that this is at the service entrance, a Type 1 or Type 2 SPD is appropriate. The main difference is that a Type 1 SPD is intended for utility side use, while a Type 2 SPD is intended for load side use.

Installation

Install the SPD as close as practically possible to the service equipment. Keep the conductor leads as short as possible, because longer leads have higher impedance at the high frequencies generated during a surge, which will reduce the performance of the SPD.

Listing

Make sure the SPD is UL 1449 listed.

Voltage Rating

Ensure the SPD's voltage rating is appropriate for your 120/240V single-phase system.

Nominal Discharge Current (In)

Check the SPD's "Nominal Discharge Current" (In) rating. A higher In rating means the SPD can handle larger surges more frequently. A minimum of 10 kA is often recommended for residential applications.

Short-Circuit Current Rating (SCCR)

The SCCR of the SPD must be equal to or greater than the available fault current at the point of installation.

3. Adding the New 200A Outdoor Load CenterYour plan to add a new 200A outdoor load center fed from the existing meter can is sound, as long as you carefully consider load calculations.

Feeder Conductor Sizing

Since the new load center will have a 200A main breaker, you need to size the feeder conductors (from the existing meter can) to carry the anticipated load. Start by calculating the demand load for the pool equipment, future car chargers, and any other loads you expect to add.

Feeder Conductor Options



Aluminum

Common sizes for 200A Aluminum conductors are 4/0 Aluminum (75°C ampacity = 180A, you may need to upsize for voltage drop).

Copper

Common sizes for 200A Copper conductors are 3/0 Copper (75°C ampacity = 200A)

Overcurrent Protection

The 200A main breaker in the new load center will protect the feeder conductors.

Tap Rules (240.21(B))

If the tap conductors feeding the new load center are shorter than 10 feet, they must have an ampacity of at least the calculated load and not less than the rating of the overcurrent protective device at the load end.

Meter Can Lugs

Confirm that the existing lugs in the meter can are rated for two conductors and are properly sized for the conductors you plan to use. This is very important.

Compartmentalization

The meter center will need to comply with the compartmentalization of the breakers.

4. Load CalculationsThis is the most important step before you do anything else! You must perform a load calculation for the entire service (house + pool + car chargers) to ensure that the 400A service is adequate. Use NEC Article 220.

Existing Dwelling Load

Perform a load calculation for the existing dwelling unit.

Pool Load

Calculate the load for the pool equipment (pump, heater, lights, etc.). NEC Article 680 covers pools.

Electric Vehicle (EV) Charger Load

Calculate the load for the EV chargers. NEC Article 625 covers EV charging. You'll need to use 100% of the charger's nameplate rating (or the overcurrent device protecting the charging equipment).

Total Load

Add all the loads together. If the total calculated load exceeds 80% of the service size (400A), you'll need to consider load management or reducing the connected load.

Important Considerations and Recommendations



Permits and Inspections

Obtain all necessary permits and schedule inspections with your local AHJ (Authority Having Jurisdiction). They have the final say on code compliance.

Local Utility Requirements

Contact your utility company (FPL) to verify their specific requirements for service upgrades, meter installations, and grounding. They may have additional requirements beyond the NEC.

Professional Electrical Contractor

This is a complex project. If you're not a licensed and experienced electrician, hire a qualified electrical contractor. They will ensure that the work is done safely and correctly, meeting all applicable codes and regulations. Mistakes can be costly and dangerous.

Voltage Drop

Consider voltage drop, especially for long feeder runs. Use the appropriate conductor size to minimize voltage drop under load.

Disclaimer:* I am an AI chatbot and cannot provide professional electrical advice. This information is for general guidance only and should not be substituted for the advice of a qualified and licensed electrical contractor. Always consult with a professional for any electrical work. Flag for review