Featured Articles

 

About Galvan Electrical >

13 Common Misconceptions of Good Grounding Practices

  1. Why use UL Listed ground rods when NEC doesn't require them?
    FACT:   Rods at least 0.625 inches in diameter and 8 feet long meets NEC, but beware of imposters. Copper rods that are 0.600 inches in diameter or less, that don't have 10 mils of copper do not meet code, but without the UL stamp, you don't know what the coating thickness actually is. Rods that aren't fully 8-feet long also do not meet code, but once the rod has been driven it is difficult for inspectors to tell its length. The UL mark - with factory ID - is the only sure way to know your rod is fully code compliant.

  2. What is the value of the UL certification on a ground rod electrode?
    FACT:   Certification of a ground rod assures your product was built to comply with NEC standards. It also simplifies inspections for the AHJ inspector since special tools and equipment are not required to ensure compliance with code.

  3. I heard copper-coated rods have a 40-year life but hot-dip galvanized rods have only a 10-year life. What gives?
    FACT:   Forget about marketing claims. The best approach is to review where the electrode will be installed and which parameters could influence service life - soil pH, electrical resistivity, moisture, stray current and proximity of dissimilar metals. Use good engineering to determine the best rod for your installation.

  4. We found corrosion in the core of a copper-coated rod to a depth of about 2 inches. Why caused this?
    FACT:   Called "tunneling," this is caused by a corrosive environment in the area of the installed rod. It's why an analysis is needed -- so you select the best type of electrode for your area. A better choice: installing a stainless steel rod: it costs more but it offers more system reliability and safety.

  5. An expert on lightning protection showed a much-deteriorated galvanized rod and a copper-coated rod only slightly deteriorated - both installed near Las Vegas. Doesn't this show galvanized ground rod's shorter life?
    FACT:   No. Soil conditions vary region to region. Galvanized rods are not the best choice in coastal installations and where soil pH is high. Copper-coated rods are a poor fit in certain clay soils that degrade protective coatings and in rocky conditions that can damage coatings to the steel rod core.

  6. Do 0.625-inch min. diameter hot-dip galvanized rods meet NEC or NESC? Any drawbacks to using them?
    FACT:   While the 0.625 inch galvanized rod is attracting some interest, there is no engineering sense for making the galvanized rod larger than the same nominal diameter as the copper-coated rod. While the rod diameter is NEC- and NESC-compliant, rod length may not meet the code. For rods that are not certified and listed, the inspector will have to dig down to determine compliance. Another possible drawback: lack of compatibility between rods, clamps and couplings when driving multiple rods to depth.

  7. What factors influence proper ground rod selection?
    FACT:   Various soil parameters are key to rod selection. Comprehensive engineering analysis is best to maximize equipment protection, system reliability and personnel safety!

  8. Do the 3-mil copper-coated rods available in the Northeast meet code?
    FACT:   Copper-coated ground rods must be 0.625 inch finished diameter with any coating type, or greater than 0.500 finished diameter and listed (e.g. UL). UL specifies 10-mils minimum coating; anything under 10 mils can't be UL Listed and violates NEC.

  9. How does the NEMA GR-1 2005 spec differ from the 2001 release?
    FACT:   NEMA chose to reduce the physical characteristics called for in 2001. We think this is a mistake since rod straightness, point and chamfers and other factors influence rod drive-ability and much of this has been reduced in the document. To benefit customers, Galvan Industries continues providing both copper-coated and hot-dip galvanized electrodes to GR-1 2001. Our UL Listed rods comply with both GR-1 2001 and GR-1 2005.

  10. Aren't all ground rods marked with a manufacturers' designation?
    FACT:   Most manufacturers only mark certified and listed rods. The Rural Utilities Services (COOP) requires markings on rods that meet their specs. Galvan marks UL Listed rods as outlined by the UL; on other rods (such as RUS compliant ones), the "G" marking signals Galvan as source. This trace-ability can be a critical issue.

  11. Compare copper-coated and hot-dip galvanized rods for corrosion factors.
    FACT:   Surface degradation depends on soil parameters, electrical stray voltage, buried materials and more. Start by reviewing the "electromotive series of metals" which defines the nobility of various metals. We know that corrosion proceeds from the anodic, or less noble coating to the cathodic, the most noble coating. Zinc sacrifices to steel; steel sacrifices to copper. So what happens when the coating is damaged to the rod steel core? Zinc coatings offer a tougher surface for driving into rocky soil conditions due to the nature of hot-dip galvanizing. Galvan produces both types of rods and is interested most in proper rod selection.

  12. About driving strength: Is your 5/8-inch nom. diameter UL Listed hot-dip galvanized rod different than today's 5/8-inch nom. diameter copper-coated rods?
    FACT:   Firms are offering all kinds of rods that may or may not meet minimal standards. At Galvan Industries, the steel core of our 5/8-inch nom. copper-coated rod is identical to the steel core of our hot-dip galvanized rod.

  13. Are any changes pending to the NEC and NESC?
    FACT:   Changes or not, NEC, NESC and even NEMA are important codes and full compliance is needed. Today 2005 NEC and 2002 NESC apply. New releases are coming in 2008 (NEC) and 2007 (NESC). Until changes are accepted by the various Authority Having Jurisdiction, Galvan will continue to produce rods fully compliant to the current standards.


   
  Ground Rod Selection Guide, IAEI Magazine
  Ground Rod Marking And Compliance Requirements
  Ground Rod Electrodes - What You Need to Know
  Grounding Vs. Bonding (from EC&M)
  Lightning Protection: Getting Grounded (from Electrical Contractor)
  Navigating the Ground Rod Electrode Maze (From IAEI News)
  Grounding Requirements For 600 Volts Or Less by John M. Caloggero.
  Why Steel Ground Rods are Copper Plated by PolyPhaser Corp.
  Introducing the Gold SeriesTM UL® Listed Ground Rods
  UL® Listed Ground Rod FAQ's
  13 Common Misconceptions of Good Grounding Practices
  Grounding Electrodes: The White Papers
  Galvan Ads Past and Present
  Galvan Archives 2007
  Galvan Archives 2006
  Galvan Archives 2005
  Galvan Archives 2004
  Galvan Archives 2003
  Galvan Archives 2002
  Galvan Archives 2001