Existing wiring: 40A breaker from main panel feeds underground wiring to sub-panel in detached garage approx. 75' from the house. The garage is about 25'x40' in size. Previous owner ran 240V compressor from that location among other things. The sub-panel currently has 4 circuits...
I changed it a while back (it used to have 3 circuits, two 120v and one 240v); I removed the 30A Double pole breaker and installed 2 single pole circuits because I didn't have a need for a 240V circuit. (removed 240V outlet).
I wasn't having any electrical issues then or now.
This is what I was leading up to:
When I changed the above circuits I noted that there was NO ground wire feed from the main panel into the garage. It could be because they ran metal conduit underground but I can't be sure; but if it is then it's been there for over 25 years.
The only wires to the sub-panel were L1 (black), L2 (red), and Neutral (white)*[there were also two smaller wires that looked to be gauge 14 or less but they weren't connected to anything at either end (house or garage) and their color codes were faded -they didn't look red/black/white/or green.
Next: What I did was to install a separate ground bus inside the panel (NOT bonded to the neutral). I then installed a ground rod and sizing the circuit I installed the appropriate solid copper ground wire. I then attached all circuit ground wires to the ground bus (as I recall, before that most of them were not connected to anything.)
Was this correct?