Okay, let's break this down. It sounds like you're approaching this methodically, which is excellent. Given your industrial background, you understand the importance of a solid grounding system. Here's a residential-focused response to your questions, keeping in mind this is general advice and you MUST consult your local codes and inspector

1. Grounding Electrode Conductor (GEC) Size and Protection:
#8 Bare Copper Size

For a 200 amp service,

#8 copper is likely acceptable as your grounding electrode conductor (GEC) to the ground rod. Table 250.66 of the NEC (National Electrical Code) dictates the minimum size of the GEC based on the size of the ungrounded service conductors (your feed wires from the utility). Since you're coming from underground, your service conductors probably don't exceed 2/0 copper, or 4/0 aluminum, meaning that #8 bare copper is good to go. 3/8" Flexible Metal Conduit (FMC)



This size conduit is usually sufficient to physically protect the #8 conductor, particularly if it's only exposed to physical damage in the immediate vicinity of the ground rod or service entrance. It does need to be protected from physical damage per 250.64. Also, the FMC must be bonded to the GEC at both ends to ensure continuity of the grounding path (NEC 250.92(B)(4)). Important note

Make sure to use appropriate fittings approved for grounding purposes to connect the FMC to the panel and ground rod clamp.

2. Bonding to Water Pipe



Yes, you likely need to bond to the metallic water pipe (if it is metallic in your house). This is the tricky part and often misunderstood, and it is not as cut and dried as some electricians lead you to believe. Why?

The NEC's requirements for grounding and bonding are designed to create a low-impedance path back to the source (the utility transformer) for fault current. This helps breakers trip quickly and prevents voltage from appearing on metal parts of the electrical system or plumbing.

How?

Run a

bonding jumper from the service equipment (your 200A panel) to the metallic water pipe within 5 feet of where it enters the building. The size of this water pipe bonding jumper is determined by the size of your service entrance conductors (the wires feeding the panel). This is per Table 250.66 in the NEC, which we already looked at to determine the GEC size. Therefore, the bonding jumper to your metallic water pipe needs to be at least #8 copper. What if the Water Pipe is Plastic? If you have plastic (PVC or PEX) water pipes anywhere in your house, then the metal water pipe is NOT used as an electrode and is not required to be bonded. If the metal water pipe is just there near the ground rod and then turns to plastic inside the house, it doesn't need to be bonded.3. Ground Rod Size



1/2" x 8 ft Ground Rod

This is the

standard residential size and is almost always compliant with the NEC (NEC 250.52(A)(5)).

Additional Considerations and Code References (Important!)



NEC 250 (Grounding and Bonding)

Read this section thoroughly. It is critical for understanding the requirements.

Local Amendments

Your local jurisdiction (city, county) may have amendments or exceptions to the NEC. Check with your local building department or inspector.

Multiple Ground Rods

If the single ground rod does not achieve a resistance to ground of 25 ohms or less (difficult to test without specialized equipment), you are required to install a second ground rod (or other grounding electrode) at least 6 feet apart. In most residential cases, two ground rods are simply installed to meet code without testing.

Splicing

Avoid splicing the GEC if possible. If a splice is absolutely necessary, use irreversible compression connectors listed for grounding.

Inspection

Call for an inspection before you bury anything! The inspector will want to see your grounding system before it's covered up.

Panel Neutral-Ground Bond

Verify that the neutral bus in your new 200A panel is properly bonded to the panel enclosure (and therefore to the grounding system). This is only done at the service entrance (first disconnect). Subsequent subpanels should not have the neutral bonded to the enclosure.

In summary

#8 bare copper is likely acceptable for the GEC to the ground rod. Protect it with the FMC, and use appropriate fittings at both ends. You probably DO need to bond to the metallic water pipe, and the bonding jumper needs to be at least #8 copper. A 1/2" x 8 ft ground rod is usually fine.

Most importantly: Contact your local electrical inspector before* you start the job! They can provide clarification on local codes and ensure your installation meets requirements.Good luck with your panel upgrade! Take your time, double-check everything, and prioritize safety. Flag for review