A #1 copper conductor with an insulation rating of 90 degrees C is rated at 145 amps.
The wire that is used for connecting the ground rod or plate to the electrical distribution is governed by the size of the electriclal distribution. In Canada a #6 bare copper is the minimum size for a 200 amp service.
For an 800 amp service with parallel sets of 500 kcmil copper conductors, the grounding electrode conductor size should be based on the largest conductor in the parallel set. The grounding electrode conductor size should be sized based on Table 250.66 in the NEC, which recommends a minimum size of 3/0 AWG copper for 1/0 AWG or larger service-entrance conductors.
For a 400 Amp service with 500 MCM conductors, the minimum size grounding electrode conductor required would be 3/0 AWG copper or 250 kcmil aluminum based on the NEC Table 250.66.
From the question it is hard to establish whether the service size is 350 amps or the service conductors are 350 MCM in parallel. If the service is 350 amps, the grounding conductor is #3 bare copper wire. Parallel 350 MCM conductors will allow for a 600 amp service. The grounding conductor for a 600 amp service is a #1 bare copper wire.
For a 200 amp service with a 60 foot run, it is recommended to use 3/0 AWG copper wire or 250 kcmil aluminum wire to ensure proper voltage drop and capacity for the load. Be sure to consult with local codes and a licensed electrician for specific requirements and installation guidance.
For a service rated at 400 amps using 500 MCM THHN copper conductors, the minimum size for a copper grounding electrode conductor (GEC) can be determined using the National Electrical Code (NEC) guidelines. According to NEC Table 250.66, for a service of 400 amps, the minimum size for a copper GEC is 4 AWG. However, if the GEC is connected to a ground rod, it must be a minimum of 6 AWG copper.
The wire that is used for connecting the ground rod or plate to the electrical distribution is governed by the size of the electriclal distribution. In Canada a #6 bare copper is the minimum size for a 200 amp service.
This answer is taken from the CEC. Table 17 states minimum size of grounding conductors. For a service conductor drawing 400 amps a #3 copper grounding conductor is needed. Also see rules 10-206, 10-700 and 10-812 if you have access to the code book.
For a 100 amp service, a minimum of 2-gauge copper or 1/0 aluminum entrance cable should be used.
A 100 amp residential service requires a size #8 copper wire, it should be insulated in green.
A size 3/0 AWG copper main bonding jumper is typically required for service entrance conductors rated at 250 kcmil copper. This is based on NEC requirements for sizing the main bonding jumper to be at least 1/10th the circular mil area of the largest service entrance conductor.
For an 800 amp service with parallel sets of 500 kcmil copper conductors, the grounding electrode conductor size should be based on the largest conductor in the parallel set. The grounding electrode conductor size should be sized based on Table 250.66 in the NEC, which recommends a minimum size of 3/0 AWG copper for 1/0 AWG or larger service-entrance conductors.
A #6 copper ground conductor would be needed.
Copper is a conductor of electricity.
On large service entrance services the neutral can be reduced. The amperage of the service and the voltage of the service and the insulation factor of the 500 MCM conductors need to be stated to answer this question correctly.
Answer for USA, Canada and countries running a 60 Hertz supply service.CEC states that a #3 bare copper conductor is a common grounding conductor size for a 200 amp service panel and it is the minium size for service raceway and service equipment of 400 amps.
For service sizes of 100 amps and less a #8 bare copper conductor is required.