The Art of Grounding

Importance of Grounding Earlier, we said that the load center was the heart and soul of the electrical system. Following that trend, the grounding system is the foundation of the electrical system. Okay, why? – An improperly grounded electrical system is: A hazard to life and property Can damage or destroy appliances Harm or kill those who come in contact with those appliances

NEC requirements The National Electric Code requires that each residence have two grounding rods (galvanized or copper clad, min 5/8” diameter and 8’ in length), placed at least 6 feet (2 meters) apart. – This is the minimum requirement! But is that really enough? – The average lightening strike has over 50,000volts of potential difference and gobs of current. Are two grounding rods enough? Probably not. – So, what can we do to “beef up” our grounding system?

Beefing Up the Grounding System We could drive in grounding rods around the entire perimeter of the house, every 6 feet and connect each one with 4/0 cable. Awesome, but expensive! – 4/0 single strand copper cable is $5 tp $8 per foot! We could attach every piece of metal (support posts, well casing etc. with 4/0 cable and tie everything in). Again, awesome, but expensive. We could design the absolute best system in the world, but again, awesome and expensive. Every installation is different. We need to weight the costs with the benefits.

Beefing Up the Grounding System Con’t Take a look at what is available: – What does the water system look like? Can we bond to the water pipe? Is there a well? How deep? – How was the home built? Steel posts? – How often does lightening strike the area? What are the risks? What are the benefits?

Beefing Up the Grounding System Con’t So, back to the “same ole same ole” It all depends Yup, it does all depend! It all depends on your situation, your budget, your risk. Bottom line, lets make the best system we can afford!

So, How do we make the BEST? Step 1: – Review all of the resources available Water system Residential Structure How much water content is there in the soil? Any other potential grounds? Step 2: – What can we connect to? Can we tie into the water system? If the water content in the soil is low, we need more points of connection!

So, How do we make the BEST? What about abandoned wells? Structural steel in the home? Existing grounds? Bottom line, look for all the sources! Then design the best you can afford but make sure to exceed the minimum! One thing that NEC doesn’t specify: – How much resistance can be in the ground system?

So, How do we make the BEST? Okay, how much resistance do you want in your ground system? – Personally, I don’t want much at all. But WHY? I want any “stray” current to find its way to ground via any path other than me or my family! Go ahead, trip a breaker, trip the main, who cares if I am alive to fix it for another day! Honestly, stray current won’t trip any breaker! We need to provide stray current an easy and fast path to ground. If not, it will use us to get there!

So, How do we make the BEST? The best ground system is the one that is properly designed for the application. – All appliances have a ready path to ground – Static electricity has an easy path to ground – Lightning has an easy path to ground – ALL electric charges can readily get to ground without going through items or people we value! Remember, Copper is an awesome conductor, use it whenever possible and practical!