
Originally Posted by
Danimal
Reading through this there are a few things that I would like to point out.
As soon as you start updating the wiring, including grounding, it has to be done up to code. This just means that the wire insulation type and conductor sizes are correct per the breaker sizing. The codes exist for a reason, so it is not a bad idea depending on how your wired, and what condition the wiring is in.
Per the NEC you can run the ground separate from the live and neutral, but I think that this is mostly for grounding of equipment where you have a neutral bonding jumper. That is the only time that I see this done as a commercial inspector. So you might be able to do it and cite the code, but the real best method would be to replace wire with correct new wire. Also keep in mind that per code you need to secure all conductors within three feet of the box, so you will need to get behind the drywall anyway to tack the ground to the stud.
Also if you are replacing your main panel it will require a permit and inspection from the city. There are a lot of things that need to be done to make the job safe. You might look at getting a quote from a licensed electrician. Take that quote look through what they recommend, and see if it is something that you can do yourself. It will give you a better idea of what would be needed and you can ask a bunch of questions to the electrician. Get a good company in there and they will tell you the best way to do it.