Power surges should I worry

[Bruce Lowekamp]

The present National Electric Code requires two 8' copper clad ground rods to be installed, spaced at least 5' apart and connected to the main electric panel ground buss, with the neutral buss then connected to the ground buss at this one location.

Also assure that your telephone and TV Cable service points are connected to this grounding system, even if the phone and cable services insist on adding their own ground rods. Just jumper connect every one of their grounds to your ground system, above the ground and in plain sight, so you can inspect these jumpers often, as most of their installers don't understand proper grounding and may attempt to remove them.

Grounding of your power system is highly important. If you have less than 2 ground rods on your electric power service you should add at least one other at the minimum. You will likely be very surprised at how much more stable your electric service becomes. I'm a licensed electrical contractor and EE (now retired and a full believer in good electric service grounding. I have solved many electric service problems in my career.

Charley

Wise words, thanks for sharing. Last year I was tracking down a ground loop in my A/V system and realized that what appeared to be proper bonding of the coax drop, wasn’t. Fortunately no damage worse than a hum....

Does a copper water pipe service count as a second grounding rod? I think my house has only one rod, but the panel is also bonded to the cold water supply via a large gauge grounding wire.

Bruce

[Charles Lent]

Bruce,

That water pipe ground was acceptable years ago as a "second ground". Now it's not, but bonding of the water pipes to your home power ground is still a requirement. They just don't call it a service ground any more. They now want two 8' long copper ground rods driven fully into the ground and spaced at least 5' apart. Since I have seen way too many problems with power systems that had neutral and ground problems, I went way beyond their requirements when doing grounding on my property. About 20 years ago my shop which is located about 200' away from the house power panel, had a 60' pine tree about 18" in diameter at 6' level and located only about 4' away from the wall of the shop with the power panel, and the lightning took out the upper 16' of this tree and opened a 4" wide slot down the tree and into the ground. It then jumped to the metal clad passage door and jumped from the upper corners of this door into the 1/2" plywood soffit, cutting two slots in it. Once inside it seemed to get into the electrical BX cable shield and then to the power panel. Between the neutral and ground busses within the panel there are scorch marks, but no physical damage other than blackened paint. A #4 bare ground wire runs out through the back of this panel, through the shop wall, and to an 8' ground rod directly below. The paint on this wire was gone after this strike. The 100 amp 3 cond. plus ground shield type UF power cable

I once worked as the sole USA electrical factory service tech for a European Printing Press Manufacturer. My territory was all 50 States plus the Caribbean. While on a service trip to San Juan, Puerto Rico, I ate at a fancy Italian Restaurant. While there eating, I noticed that the restaurant lights were flickering and going very bright occasionally. I made a comment to my waiter about it and told him that I thought that I knew what was wrong. His eyes got big and he ran to the kitchen. A moment later the chef/owner and the waiter were running out of the kitchen to talk to me. I was about finished with my meal, but told them what I thought was the problem. He wanted me to fix it for him, but I told him that I was on a business trip and did not have tools and supplies with me to fix it. He then asked me to show him the problem. He said that he had had several electricians look at the problem, but none of them could fix it, and he pleaded with me to at least show him what the problem was so he could get the electricians back to fix it.

So when I finished eating, I got up, and followed them back into the kitchen and to the restaurant electric panels. I opened the covers and wiggled some of the connections. When I moved one of the Neutral connections in the main fuse box (yes fuses), the terminal and wire were loose and sparked. I got lucky, because my tools and test equipment were all back at the print shop. I asked the owner if he had a large insulated screwdriver, which he brought me quickly. I tightened the screw terminal , and there was no more flickering light problems or surges. The owner was watching me this whole time and began dancing for joy when the flickering problem went away, almost like magic to him. I told him that since I did not have tools or supplies with me, that he would need to get someone to replace the terminal and wire as soon as possible, since both were now damaged and would likely go bad again very soon if not replaced. He agreed to do this.

He would'nt take any money at all for my meal that night, not even for the bottle of wine, and he told me that he wanted me to come back another night for another full free meal with wine and desert. At the end of the week and just before leaving San Juan, Puerto Rico, I did go back and have another wonderful, and free meal. By then, his electrician had fixed the wire and terminal, and the owner was still dancing and smiling every time that he went past me, while making certain that my meal was perfect each time.

Bad neutral and ground problems can cause all kinds of weird problems. Take good care of their connections. Old main fuses can sometimes go high in internal resistance and cause problems that are very similar to neutral and ground problems. If fuses are involved, it's a good idea to remove them and check them for internal resistance too. Replacing main fuses every 10 years or so would be a good idea too. They aren't that expensive and can cause all kinds of strange problems as their internal resistance goes up from age.

I once took a call for a problem and when I got there the woman told me that every time she flushed the toilet, that the TV would shut off. She wanted to know if she should call the TV repairman or the plumber. It turned out to be a high resistance main fuse on the same power line that fed both the TV and the well pump. When the well pump started, it dropped the line voltage on the TV branch circuit low enough that the power relay in the TV would drop out, yet the TV could be powered back on with no problem.

Another similar problem from old main fuses caused the living room lights to be bright when the electric clothes dryer was running, but would dim about 10% when the dryer shut off. Again, it was a high resistance main fuse. When the dryer was running, it was wired across the 240 volt lines, so it passed enough voltage through it to raise the voltage on the line that the living room lights were connected to. Other electricians had not been able to find this one either, but I did.

Charley