Grounding for Amateur Radio Harold C. Fleischer, III AE5AS 11/10/2018

V = I x R Voltage = Current x Resistance Grounding For Amateur Radio Ohm’s Law V = I x R Voltage = Current x Resistance 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Ohm’s Law V = I x R Voltage = Current x Resistance V = I x Z Voltage = Current x Impedance 11/10/2018 Grounding For Amateur Radio

Ohm’s Law V = I x R Voltage = Current x Resistance V = I x Z Voltage = Current x Impedance V = ((1/C) ∫ i dt ) + (i x R) + ( L x (di/dt) ) Voltage = Capacitance divided into the integral of Current over time + Current times Resistance + Inductance times the derivative of Current over time This equation is why imaginary numbers and polar coordinate mathematics appear in the license examination for Amateur Extra. 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Battery and Voltage + No Impedance Battery Voltage No Current - 11/10/2018 Grounding For Amateur Radio

Basic Complete Circuit + Impedance Battery Voltage - Current Exists 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Short Circuit + Battery Voltage No Impedance - Current  Infinite 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Open Circuit + Battery Voltage No Impedance - No Current 11/10/2018 Grounding For Amateur Radio

Basic Capacitance Circuit + Capacitance Battery Voltage - DC – No Current 11/10/2018 Grounding For Amateur Radio

Basic Capacitance Circuit + Capacitance Battery Voltage - DC – No Current Can Current jump the gap in a capacitor? 11/10/2018 Grounding For Amateur Radio

Basic Capacitance Circuit + Capacitance Battery Voltage - DC – No Current Can Current jump the gap in a capacitor? Yes, capacitors have a breakdown voltage. 11/10/2018 Grounding For Amateur Radio

Can Electrons Jump Air Gaps? + Battery Voltage Spark Plug - Current Yes, spark plugs in a car, etc., are all about jumping an air gap to create a spark. 11/10/2018 Grounding For Amateur Radio

Lightning Jumps Air Gaps + When Voltage from static electricity gets high enough, electrons will jump the gap and produce thunder and lightning Voltage Currents will be brief, but very high. - Ground 11/10/2018 Grounding For Amateur Radio

Electrons Always Want to go to Ground + Voltage + Radio Transceiver Voltage Ground - - 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Basic Ground Problem Vm + Voltage Impedance Battery - Vc0 Current Exists If Vc0 does not equal Vg, Electrons want to get to ground. - Vg Ground 11/10/2018 Grounding For Amateur Radio

Basic Electrocution Problem Vm + Battery Voltage Impedance - Vc0 Current Exists - Vg Ground 11/10/2018 Grounding For Amateur Radio

Basic Grounding Solution Vm + Voltage Impedance Battery - Vc0 Current Exists Vc0 = Vg, and you are no longer the best path to ground. Grounding Wire - Vg Ground 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Basic Grounding Truth Grounding is like Pregnancy You are Grounded or you are not Grounded. There is no such thing as partially Grounded. Ideally, you have a Ground when the ground resistance value is 0 ohms. NEC requires a ground resistance value of <25 ohms. NEC recommends a ground resistance value of 5 ohms or less for sensitive equipment. Type of soil affects what you have to do to get a good ground resistance value. 11/10/2018 Grounding For Amateur Radio

Ground Resistance Measurements Very complicated; not necessarily inexpensive. Must drive ground rod and then other rods to do measurements. Meters can cost upwards of $200-$300. The default is to follow the NEC. Install ground rods or ground plates. 11/10/2018 Grounding For Amateur Radio

Grounding Rods and Plates Grounding Rod must be: Copper or copper clad aluminum. At least 8’ long with only 3” showing. At no more than an angle of 45 degrees when driven in. Measuring Ground Resistance is complicated. Mechanical Clamp of AWG 6 copper wire or braid. (A high current will melt solder.) Grounding Rod may be placed horizontal in a 30” deep trench if they can not be installed vertically. Grounding Plate must be: 2 feet square ( 1’ x 1’ x 2 sides). ¼” thick if ferrous, 1/16” thick if non-ferrous. Hole in center for bolt, nut, and lock washer. Top of plate must be 5’ below the surface of the ground. (The more square feet in the plate, the more likely Ground Resistance measurement objectives will be met.) 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Grounding in a House Meter Panel Grounding Wire Grounding Rod Black – Hot White – Neutral Green - Ground 11/10/2018 Grounding For Amateur Radio

Example of a House Ground Grounding wire in protective cover 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Bonding Bonding is Grounding Bonding is tying equipment together to eliminate or dampen inter component electrical interaction: Noise 11/10/2018 Grounding For Amateur Radio

Number of Grounds for your Property ONE 11/10/2018 Grounding For Amateur Radio

Multiple Grounding Rods - One Ground Shortest Path matters Ground from Meter/Panel goes straight down to Grounding Rod Ground from Antenna needs to go straight down even if antenna feed cable has to make a turn to the “Radio Shack Ground from “Radio Shack” needs to go straight down Ground from Tower needs to go straight down Tie all ground rounds together with AWG 3/0 buried 18” deep. 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Grounding Example 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Grounding Example Example of Lightning Arrestor (Surge Protector) at bottom of drip loop. 11/10/2018 Grounding For Amateur Radio

Grounding Example Site Plan House Grounding Rod HF Antenna Patio VHF/UHF Antenna Grounding Rod 18” Trench with Grounding Cable Remember: Number of Grounds on Your Property? ONE 11/10/2018 Grounding For Amateur Radio

Grounding with Tower Example House (with no antennas mounted on it) Grounding Rod (Electrical Service) Patio Grounding Rod (Radio Shack bonding) 18” Trenches with Grounding Cable Remember: Number of Grounds on Your Property? ONE Tower Bonded to Antenna, Each Leg with Grounding Rod, Leg Grounding Rods 6’ apart, & Leg Grounding Rods joined by Ground Wire 1’ deep 6’ 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Emergency Generators OSHA Fact Sheet Frame of portable generator may serve as ground if: Generator supplies only equipment mounted on it or cord connected equipment through receptacles mounted on it. Non-current metal parts of equipment are bonded to the frame and grounding conductor terminals are grounded to the frame. Do not connect a generator to a structure except through a transfer switch. Very sensitive situation that may require generator to be grounded. 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio Review You ground to: Protect against an electrical fault Protect against lightning Suppress noise in electrical equipment 11/10/2018 Grounding For Amateur Radio

Grounding For Amateur Radio References ARRL Handbook, Chapter 28.1, 91st Edition, 2014. Silver, H. Ward, N0AX, Grounding and Bonding for the Radio Amateur, ARRL, 2017. Morgan, Jennifer, and Chusid, Michael, Lightning Protection for the Amateur Radio Operator’s Home, QST, ARRL, June 2017. CECOM TR-96-2, Earth Grounding Pamphlet, May 1996. OHSA Fact Sheet: Grounding Requirements for Portable Generators, DSTM 10/2005. 11/10/2018 Grounding For Amateur Radio