You need two forms of grounding according to the code. Grounding to the water main is typically the best ground in a building. If you don't have a water meter you can add an extra ground rod.
Unless otherwise specified you need a 5/8th inch by 8 foot copper clad rod. A great trick is to drive it in at a 45 degree angle and bend it up as you go so it ends up straight after it drive in all the way. This keeps you from hitting hard pan and keeps you from having to get on a ladder to drive the rid which can be kinda dangerous. Leave about 4 inches out of the ground for you ground clamp. For a 200 amp service use #4 armored ground. For 125 amp or 100 amp you can use #6 armored ground wire and an armored ground clamp. The NEC allows that for ANY connection to ground rod, #6 solid copper is the largest conductor required. The ground rod is SUPPLEMENTAL, and only in rare circumstances is the ground rod your primary ground. The sizes given above are for your primary grounding connection, such as a metal water line.
You will need two 8 foot ground rods. One placed under the meter base and another one placed 6 feet to the side next to the foundation. If this is a home I highly recommend you install a 200 amp service instead of a 100 amp service. Not much more expensive and you will have plenty of room for growth.
As long as the clamp is of an approved type only one is needed per ground rod.
The NEC makes no provision for using 1 ground rod even on a temporary service. According to the NEC you must use 2 ground rods. However in my area we are allowed by the local inspector to use just 1. Call your local inspector and see what he requires as he has the last word on this.
In Canada it is a #6 bare copper conductor that connects the grounding rod or plate to the neutral point in the distribution panel.
Purchase a ground rod from an electrical supply. Drive it into the ground just outside where your service is located. Install a ground cable from the neutral bar in the fuse box to the ground rod and clamp both ends. Voila, you have done it!
The wire size used in a service entrance distribution panel is governed by the size of the services over current device. The larger the service, the larger the fault current could be, the larger the ground wire to carry the fault current to ground. If the largest service conductor carries 100 amps use a #8, 200 amps - #6, 400 amps - #3, 600 amps - #1, 800 amps - 1/0 and over 800 amps - 2/0 for the ground wire. <<>> Golden Valley Electric Assoc. in Alaska requires #4AWG copper wire for a ground from the breaker box to earth ground rod. The same goes from the service entrance panel on the pole.
It is the installation of ground rods at a service entrance distribution to bring the relative resistance to ground to be within 5 ohms of the utility's distribution network. This grounding system is then connected to the service distribution with a calculated size wire and connected to the distribution at a point within the distribution panel, where the service neutral wire joins the neutral bus bar.
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.
#8 would be fine if you ground each panel separately to the ground rod
#6 should be fine...Canadian Code anyway....
EarthIts a earth groundat lower potential then your service
Connect other end to the ground lug in the service entrance part of your panel.
#8 is the size of wire to use for grounding a 100 Amp panel. Green is color used for grounding #8 is code.
5 feet
You need two forms of grounding according to the code. Grounding to the water main is typically the best ground in a building. If you don't have a water meter you can add an extra ground rod.