Hello everyone. I live in Miami Florida. I have a issue of concern as to the
Proper grounding of my distribution panel.
I have a detached garage about 70 feet from my home. I have a Square D 200 A
Combination service entrance device on the outside garage wall. The garage has
It's own distribution panel, mounted inside on the wall behind the service
Entrance box. There is a rigid metal conduit pipe from the garage distribution
Panel to the house distribution panel. There are 2 conductors and a neutral
Running from the service entrance box, through the garage panel, through the
Rigid metal conduit, to the house panel. The garage panel is fed from it's own
60 amp breaker in the service box. I have a ground rod with #4 connected with
The neutral in the service entrance box. I have #4 connected from the service
Box to the ground bar of the garage panel.
I have no ground wire running to the house panel. I don't think I have room in
The rigid metal conduit to run the ground wire and I fear damaging the cable or
Getting the snake stuck. There is a 1 inch copper water line between the service
Box and the house panel. I can also run a #4 ground wire ( separate from the
Rigid metal conduit ) from the service box to the house panel ( if necessary ).
I can also install a ground rod at the house panel.
What should I do??
Can I use the water line as a common tie point between the service box and the
House panel, and/or Do I need to run a separate #4 wire between the service box
And the house panel, and/or Do I need to install a ground rod at the house
Panel??
Also, I am installing a standby generator that will feed power through the
Service box via a Square D generator interlock kit, back feeding through a 100
Amp breaker. The generator will be located about 30 feet from the service box.
What would be the proper way to ground this?. THANKS

No, do not try to shove a snake through a conduit with wires already in it, damage to the wires is very possible, as you mention.

The rigid conduit is considered as the equipment ground.

Any panel in a separate building must be grounded to either city water line and/or a ground rod, or more.

The neutral and equipment ground at the house panel needs separated.

The water line should be bonded to the panelboard neutral/ground with a #6 copper wire and a ground clamp, at any building that has access to water line.

The genset may need to have a ground rod driven, check manufacturers instructions,and connected to the frame of the genset with a #6. The neutral and equipment ground does not need to be connected together at the genset.

The feeder from genset to panel needs to be 4 wire, including the equipment ground.