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Grounding and Bonding for the Amateur

The ARRL's Book on Grounding and Bonding

Overview and Directions-

This web page is for information that extends or supports the book Grounding and Bonding for the Radio Amateur.  The book brings together material from numerous Amateur Radio and industry sources to present a comprehensive picture of basic grounding and bonding practices related to ac electrical safety, lightning protection, and the management of RF currents and voltages in the typical ham station.  The book is intended to be of the most use to new station builders and those upgrading an existing station.

The material below is organized as Resources, Supplemental Information, Examples, and Errata.  In the Resources section, you'll find a list of articles, websites, and vendors for materials and techniques referenced in the book. The Supplemental area extends discussions in the book or explores topics the book doesn't cover.  the Examples area features photos and comments by other amateurs intended to show how they solved a problem or implemented some of the suggestions in the book.  Finally, as the inevitable errata emerge, they'll be listed here - check this section before reporting a possible error.

Thanks for reading - we hope this book helps you build an effective and well-behaved station!

To purchase the book, click here or browse to the ARRL Store where you can also find numerous other technical publications supporting Amateur Radio.

Supplemental Information and Errata

  • Resources for Materials, Products, and Methods

    General RF Websites

    RF Cafe: many tutorials, calculators, references, standards, etc.

    Microwaves101: a general-purpose site dealing with RF above 30 MHz

    Repeater-Builder: numerous links and articles, technical manuals, and instructions

     

    Electrical and Electrical Safety Websites

    Mike Holt Enterprises: numerous tutorials and explanations of safety practices

    International Association of Electrical Inspectors: information on electrical safety

    Polyphaser: various papers and tutorials on lightning protection for communications facilities, including ham stations

    Lightning Protection Institute: papers and tutorials on lightning protection techniques

     

    Useful Standards

    National Fire Protection Association: free access to the latest version of the NEC.  The NEC Handbook 2017 is available through libraries.

    FAA Document on Practices and Procedures for Lightning Protection, Grounding, Bonding, and Shielding Implementation

    Motorola Publication R56 - Standards and Guidelines for Communication Sites
     

    IEEE Std 1100 – 2006 “IEEE Recommended Practices for Powering and Grounding Electronic Equipment” (available from most libraries)

    MIL-HDBK-419A – Grounding, Bonding, and Shielding for Electronic Equipments and Facilities (Vol 1 and 2)

    Underwriter Labs free "White Book" - addresses the suitability of a device or material for a particular application.

     

    ARRL Websites

    ARRL Technical Information Service sections
    Electrical Safety
    Grounding (various types and topics)
    Lightning Protection

     

    Miscellaneous Websites

    K9YC's Tutorials and Papers: Jim Brown, K9YC, has published a number of useful papers and presentations for hams.  His tutorials on ferrites and RFI are widely referenced, including by the ARRL.

    W8JI's Lighting and Groundieng Pages: Tom Rauch, W8JI, has documented his grounding and bonding techniques to reduce lightning damage, noise, and RFI in his large station.  Many good photos and sketches illustrating the concepts in this book.

     

    Miscellaneous Books and Articles

    • P. Laplante, Editor, Comprehensive Dictionary of Electrical Engineering Terms, CRC Press, 1999
    • Ugly’s Electrical References — pocket-sized references of electrical information for wiring, common electrical circuits, and materials
    • Block, R. R., The “Grounds” for Lightning and EMP Protection, Second Edition, PolyPhaser Corporation, 1993.
    • Rand, K. A., Lightning Protection and Grounding Solutions for Communications Sites, PolyPhaser Corporation, 2000.
    • Uman, M. A., All About Lightning, Dover Publications, Inc, New York, 1986.
    • Uman, M. A., Lightning, Dover Publications, Inc, New York, 1984. Uman, M. A., The Lightning Discharge, Dover Publications, Inc, New York, 2001.

  • Supplemental Discussions and Topics

    WARC Band Chokes

    Table A.5 - Ferrite Transmitting Choke Designs
    For 18 and 24 MHz, us the second line of the 21 MHz entry

    Table A.6 Coiled-Coax Transmitting Choke Designs
    1.8 MHz - this technique is not recommended
    18 MHz - for RG-213 and RG-8, use 9 feet of cable, coiled into 6-7 turns; for RG-58, use 7 feet of cable, coiled into 8 turns
    24 MHz - for RG-213 and RG-8, use 7 feet of cable, coiled into 6-8 turns; for RG-58, use 5 feet of cable, coiled into 7 turns

     

    Old Power Strips with Surge Suppressors

    The recommendation to avoid surge protectors was aimed at the inexpensive power strips that don't meet UL 1449 or that were manufactured before 2009 when the current version of that standard went into effect.  In addition to UL 1449, IEEE C62.62 establishes methods for testing and measuring the performance characteristics of Surge Protective Devices but doesn’t specify limits or ratings of any sort. IEEE 62.72 is a guide for manufacturers to aid in the selection of SPD’s for use on the AC mains, which is heavily biased towards MOV performance.  Those old strips are still powering a lot of stations - the author found two bad strips in his own collection, for example.  If you can't be sure the surge protection is up to current standards, remove them.

     

    Building Your Own Power Distribution Box

    Some readers asked about where to get multi-outlet cover plates.  The words to use in an Internet search are "5-gang duplex receptacle wallplate" - you will discover a number of sources.  Wallplates are available with quite a variety of configurations and sizes.  Here is a 5-outlet wallplate similar to that shown in the book.

     

    Building the power distribution center requires attention to detail if you want the one you build to be safe.  Using in-wall back boxes is not OK in a wet environment, for example.  Be SURE the ground conductor is securely attached to the metalwork and can't come loose.  Plastic-housed strips meeting current standards are OK in this regard although they can't be grounded directly to an entry panel.

     

    AC Surge Protector

    The "dedicated ac surge protectors" provide surge/transient protection for an entire branch circuit and are mounted on a grounded panel or surface.  The Tripp Lite and Polyphaser guides to surge protection might be helpful in selecting an appropriate model.

    DX Engineering sells panel-mounted ac line protectors for the amateur station
    Tripp-Lite manufacturrs a wide range of ac surge protectors and line conditioners such as the 600 W 120 V panel-mountable LS604WM.
     

    Portable GFCI - "GFCI In a Box"

    Correcting material in the book - individual GFCI outlets are not intended for outdoor or portable use but there are portable GFCI units available (such as this one from Woodhead) that don't require assembly. The are designed to require line voltage be present before they can be "set" to operate, and disconnect automatically if either the hot or neutral connections are lost.

    The GFCI-in-a-box as pictured is unsuitable for permanent outdoor installation, which wasn't the intent, but building the unit to be weatherproof can't hurt.  Your local electrical aisle will have suitable weatherproof boxes and covered outlets such as these from Lowe's:

    Electrical box  (you'll need a plug for the holes, too, or a sealed plastic box can be used)
    Weatherproof cover
    Sealed cord strain relief

    You can also buy GFCI kits for outdoor use and installation - here's a photo of mine.  This box is sealed and has a waterproof cable entry, as well.

     

    Installing a GFCI Receptacle - this downloadable PDF is a leaflet included by many manufacturers with GFCI receptacles purchased separately.

     

    If you do build the GFCI-in-a-box or add a GFCI to a homemade power distribution box, the NEC specifically prohibits connecting multiple GFCIs in series. Standalone GFCI boxes should not be plugged into another GFI or GFI protected outlet, which should be present in any situations where water is within 3 feet of an outlet (RVs, park shelters, etc.)  Field Day generators may or may not be GFCI-protected - the popular Honda EB2000i generator outlets are GFCI-protected, for example - so check first.

  • Contributed Examples of Grounding & Bonding

    If you would like to contribute an example of your own, please contact the author at n0ax@arrl.org or pubsfdbk@arrl.org.

     

    Bonding

    Jim Brown, K9YC, sent this photo of grounding jumpers (green wires) in the back of a nice portable station built by Glen Brown, W6GJB, for the California QSO Party.  The jumpers are all short and direct, keeping the equpment bonded together at RF.  Note the use of Powerpole connector to make disconnecting easy. The use of the standard green insulation and connectors for equipment ground wiring also makes the wires easy to identify as ground.

     

    Single-Point Ground Panel (SPGP)

    Contest operator K4RO decided to install a large SPGP to improve his station's ability to deal with lightning and to minimize RF voltage differences throughout the antenna switching and filtering system.  The panel is installed on an exterior garage wall under his station - which is effectively a second-floor station.  The ground conductor is attached at the upper right to ground rods installed outside the wall.

     

    RF Ground Plane

    Ken Chechura, KC9UMR, was rebuilding his station and got a great deal on some surplus wire rack shelving.  Not only does the wire mesh act as an RF ground plane, it provides for airflow that ventilates and cools the equipment, as well.

     

    Lightning Protection

    This shows a set of DX Engineering lightning protectors mounted on an aluminum angle bracket at the author's station.  The bracket is then attached to a grounded aluminum panel.

     

     

     

     

  • Errata - 29 August 2017

    Page 3.16 - References to GFCI on this page are to Ground Fault Circuit Interrupters which are discussed beginning on page 3.20.

     

    Page 4.31 - The guidelines for minimum conductor bend radius for above-ground wiring require an 8" minimum radius, not 12".  The larger radius may apply to buried conductors according to a variety of industrial recommendations that depend on the application and local building codes.