This has been a baffling question as I notice electrician charge an arm and a leg to upgrade electrical systems in a home. My home was built in the 1930s and it’s not grounded. I was wondering if a grounding rod is just a long stick that goes deep down in the ground. If so, how deep should I drill? Second, if I just connect that to the cold water pipe, I can ground all my outlets to that cold water pipe?
You may not use water pipe in your home as a substitute for ground wiring between outlets and panel. That won't work, isn't legal and will create the illusion of safety - a lot like taking your shoes off at the airport.
However in 2014 the rules for properly retrofitting grounds were greatly relaxed. It's no longer necessary to replace the entire cable, now you can simply fit a bare or green wire between the outlet and the service panel which serves it.
There's a lot more to a grounding system than that
Electricity travels in loops. It wants to return to the generation source, not ground. Ground isn't a very good conductor anyway. There are two general groups of threat:
- natural electricity that actually does want to return to ground, because that is its source -- lightning and ESD.
- man-made electricity which is not where it should be. We want it to find an alternate path back to source that is much better than shocking a human.
Grounding systems are confusing because they are trying to solve two very different problems at once. As such, they do two very different things at once. Do not confuse them. Do not think one is a substitute for the other.
The heart of it is the service panel
Inside your service panel, you have two buses: neutral and ground. Neutral is the normal current return back to source. Ground is the equipment safety grounding system, designed to catch abnormal current flow. Neutral and ground are kept rigidly separated.
Neutral is bonded to ground at exactly one location: the main service panel, and this is called the neutral-ground bond. This can look pretty casual: sometimes you see bars with all the neutrals and grounds spammed onto the same bar, that had better be the main panel. In a subpanel they are rigidly separated.
What does this neutral-ground bond do? First it assures that abnormal current caught by the grounding system is able to return to source. Second, it makes sure all the conductors remain at sane voltages compared with your grounding system (e.g. in case the power company's transformer has a problem).
The grounding electrode system
This system provides a connection to actual physical earth. Yes, it can involve a water pipe. Code specifies what is acceptable. Do one of those.
It's then tied to the ground bar in the main service panel. Other grounding electrodes may be required, i.e. At outbuildings, and those are also tied to the grounding system.
What does the grounding electrode system do? First, it provides a route for natural electricity to return to its source - earth. Second, it gives the ground bond a way to pull neutral down to actual earth voltage (or to be more precise, pull the earth around your house up to leaky-transformer voltage, which is the least ugly way of handling that problem.)
From the ground bar, runs to every outlet
And don't do a homerun for each outlet. When you are retrofitting grounds, circuits out of the same panel can share the ground wire, as long as it's big enough. So you don't need to reach the panel, any other grounded point will do if it's big enough. So you can do a "tree" layout for all your grounds. You can share grounds when retrofitting, you cannot share neutrals.
Ground wires do not need to follow the route of the live wires. They can use any practical route.
Start by planning a ground wire to hit your biggest loads, which will be #10 or so. Then provide junction boxes in the right places so your smaller ground wires can start at one of those, and then daisy chain to all your outlets.
To get ground wire, you can shuck down old Romex that is damaged or otherwise unusable. You need to strip it down to bare wire (so ratty or damaged insulation won't be a factor). Don't use nicked or damaged parts, obviously. Copper is a pure metal that inherently resists corrosion and doesn't go bad.
Yes, you can install a ground rod yourself. They are typically 5/8"-1/2" thick 8' long copper rods, which need to be driven entirely into the ground. It's common to use a large hammer drill, or small jackhammer, with a ground rod driving bit, to drive the rod.
However... Driving and connecting a ground rod, is not all there is to grounding an electrical system. If you really want to do this work yourself. Find a person with knowledge and experience with this, that is willing to teach you. If you can't find somebody, go get a couple books on the subject. Study the books cover to cover, and make sure you understand the information before you begin work.
And no, you do not connect things to the plumbing to ground them. Though you can sometimes use the service plumbing as a grounding electrode, and you will have to bond any metal plumbing within the building.
Grounding isn't about connecting to the earth (dirt), it's providing a safe, low resistance path back to the source (service). While ground rods (and other electrodes) are part of the grounding system, they are not the most important part of the system.
My house has 2 ground rods and is also grounded to the sweated copper water supply lines.
Originally the electric panels in our neighborhood of 250 tract houses (built 1970-71) were grounded only to the sweated copper water pipes (in our house to the cold supply line to the clothes washer in others the cold side of the tank water heater). I wanted to install a ground rod in the earth next to the electric meter, but never got around to it. When I would be at the home store I would look at the 8' grounding rods, etc., but knew there were specifications about location and spacing which I didn't know so I dithered and procrastinated.
Maybe five years ago I asked an electrician doing work across the street to install a ground rod and he did it quickly. Not long after that there was a terrific lightning strike near us causing damage in the houses on both sides and across the alley, but we had none.
What I have done is to use a length of 1/2 in. copper pipe. I rigged a hose connection and used water to "jet" the 10 ft length into the ground . It depends to a degree on the soil ; mine is sandy and it worked very well compared to the electrician who drove the traditional copper plated steel bar with a hammer. I have not looked it up but I expect my copper pipe has a lower resistance than the usual copper plated solid steel bars.
Both the 2014 & 2017 code allow this. I just checked code on this NEC on this 250.130.C non grounding receptacle replacement or branch circuit extension. Any accessible point on the grounding electrode system or any accessible point on the grounding electrode conductor. If supmental rods are driven and the pipe is bonded to be part of the grounding electrode system it would be legal to connect to the pipe.