A typical panel has three large wires entering the main panel from the electric meter and a bare ground wire. Two of the large wires are hot and go to the busses where the breakers are mounted. The third wire is common and is connected to one or more common bus locations. It will usually be silver in color with a screw on top to connect white wires from branch circuits. The ground is the metal of the panel itself and there will be one or more ground busses usually copper colored that are connected to the metal of the panel by screws there by "bonding" these ground busses to the metal of the panel. You should also see a copper wire coming from a ground rod connected to the metal of the panel.
At the main panel you need to bond the common to the ground. There is usually a screw that allows this bonding to occur. If you have subpanels ground and common are NOT connected at the subpanels.
A 100-A sub-panel would be fed from a 100-A breaker.
Yes. Many installations have breaker totals higher that the main breaker of the panel. It is worked on a percentage basis. Not all of the breakers will be on at the same time. In a home, on a 100 amp panel the average load is 50 - 60 amps. The 100 amp main breaker is protecting the 100 amp rated panel board. If the load current goes higher that the panel board is rated at, the main breaker will trip to protect the board.
If the sub panel is in the same building remove the bonding screw that bonds the neutral bar to the panels enclosure. Remove the ground from the second ground rod. The sub panel is grounded by the ground wire from the sub panel's feeder. If the panel is separate from the main building treat the sub panel as a separate service. It will need its own ground rods and ground wire from the rods to the neutral bar of the sub panel. Leave the bonding screw in. There will be no ground wire in the conduit between the two services.
You should not load a 125 amp panel any more than 100 amps.
# 10 bare copper.
A 100-A sub-panel would be fed from a 100-A breaker.
#8 would be fine if you ground each panel separately to the ground rod
#8 is the size of wire to use for grounding a 100 Amp panel. Green is color used for grounding #8 is code.
In the service distribution panel there are termination points at the top of the panel. Two of the utilities "hot" conductors terminate on the main breaker. The neutral utility termination point is on a terminal block usually off to the side near the main hot terminations. It is in this neutral termination block where the system ground connects from the ground rods to the distribution panel. For a 100 amp panel the wire size will be a #6 bare copper conductor.
If what you state in this question is accurate this is an illegal installation. A 100 amp service can not have any equipment connected to it less that that of the service size. The 60 amp main panel must be a 100 amp panel to be a legal installation.
#2 aluminum for 100 amp
you propaly can't sub panel from 100 amp panel. Just not enough amperage to be worth while. i had to up grade t a 200 amp main first and then I was able to take a 60 sub panel from that.
Yes, but at every reduction in wire size there has to be a breaker sized to the smaller wire size. The wire size for 100 amp panels is recommended at #3 copper conductor. From the 200 amp feeder panel you will require a 100 amp two pole breaker for each of the two 100 amp services. Keep in mind that if you run the 100 amp services close to maximum this will take away the capacity of the 200 amp service for other branch circuits coming off of it. Also keep in mind that if the panels are located, not in the same building as the 200 amp service that the 100 amp panels will be treated as separate services and will have to be constructed like a 100 amp service. This includes ground rods. Also the bonding screw will have to be removed that connects the neutral buss to the panel enclosure.
Ground the meter base only if it's a duplex. Otherwise, ground at the main switch or panel.
There are two things to think about here. First of all a 200 amp breaker will not physically fit into a 100 amp panel. This is so designed because the panel buss is not designed to conduct 200 amps before the current is cut off. A 100 amp rating on the panel is the maximum amount of current that the manufacturer states, that can be handled safely. Second if the 200 amp breaker is in the main panel then everything downstream from that breaker has to be rated for 200 amp conductivity. The wire size will have to be 3/0 from the breaker to the first over current device in the sub panel which will be the sub panel's main breaker. The sub panel can not be a load center but will have to be a combination panel. I doubt that the 100 amp sub panel's main breaker lugs would be large enough to connect the 3/0 cable.
It may be the GFCI breaker is defective. Make sure it is wired correctly. Neutral to neutral bar and ground to ground bar.
20Sqmm