Is Your Home Properly Grounded?
Is your home properly grounded? Read on and I’ll tell you a few things to look for in order to answer that question about electrical grounding and making sure that your home’s electrical system is safe.
First of all, you should be aware that a good grounding system is essential to the safe operation or your electrical system. The National Electrical Code gives an entire list about of acceptable methods to use for grounding. In this article, I’m only going to talk about two of them because they are the ones that you normally see in homes.
Metal Water Pipes
A lot of homes have metal water pipes, either copper of galvanized. Metal water pipes are an excellent grounding path because they go into the ground for quite some distance and are an excellent grounding electrode. You should make sure that, on this copper or galvanized pipe, you have a ground clamp and a ground wire going to your electrical system. The ground clamp needs to be within five feet of the entry of the pipe to the home–that’s a very important point.
Something else that’s important–and I want to mention it here because it’s something we see quite often–is plastic water pipe. Now, if you have a plastic water pipes throughout your home obviously you can’t ground to that and you’ll have to choose another grounding method. But even if you do have a metal piping system, and you have had some plumbing repairs done at some point, the plumbers may have put in a piece of plastic pipe in the course of their repair work. If that is the case, they have also essentially destroyed your grounding system–you have no ground, at least not through your water pipe. So it is absolutely vital that you put a clamp on each side of any plastic pipes and run a conductor of the proper size in between the two clamps in order to keep the ground path intact. If not, as I said above, you have no ground. We see this all the time, so make sure that if that’s the case in your home when you’ve had plumbing repairs done, that there are two clamps and and a conducting wire put in to span the plastic pipe so that the grounding path isn’t broken.
The other method of grounding we commonly see in homes is a grounding rod. It is typically 8 to 10 feet long and has a clamp at the top to which the grounding wire is connected. The grounding wire is the grounding electrode conductor that connects your electrical grounding system the the ground rod.
An important thing for your electrician to check is the resistance to ground measurement, which should be 25 ohms to ground or less–it’s important that you have a low resistance path to ground.
To sum up, your home will have one of two grounding methods, a metal pipe or grounding rod system. If your not sure whether or not your home’s electrical system is properly grounded, and you live in the Santa Barbara area, give us a call at Left Coast Electric and we’ll be happy to come out and have a look.