I'm helping a friend upgrade two panels on a duplex he owns. The panels are right next to eachother. Each panel will be 100 amp.
The plan is to go up with one riser rated for 200 amp and bring that into a gutter. From the gutter, split into two 100 amp panels below.
I'm familiar with grounding for regular single family homes, but in this case I'm not sure if I'm needing to double up all the grounding.
I don't have a ufer so I'll use the water main as the main grounding electrode (it is metal going into the ground), secondary electrode will be a 8' ground rod. Lastly, I'll bond the gas at the hot water heater. All of this will be done in #4 bare wire.
This being said, I'm sure I don't have to put in two ground rods and run two #4 wires to the water for each panel. How is this normally done?
Any suggestions or advice on this would be appreciated... also, what is the differnece between grounding and bonding?
Thanks,
