Grounding & Bonding - Ward Silver - N0AX
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- čas přidán 30. 06. 2024
- A lot of folklore and controversy exists concerning proper grounding and bonding for a ham radio station. Learn more about these topic by attending our August 18th DRC on-line meeting presentation.
Well known author Ward Silver, NØAX, will discuss the following topics:
~ The definition and proper use of the terms “Grounding” and “Bonding”.
~ The various requirements for AC safety (the National Electical Code), lightning protection and RF.
~ Issues and techniques for building home ham stations.
~ A common grounding and bonding system that satisfies all the necessary requirements.
~ Comprehensive sources of information about grounding and bonding for amateur radio.
Ward was licensed at age 16 in 1972. Ham radio led him to a BSEE in 1978. Besides being very active in various ham activities, Ward has published many ham related books and even a ham radio novel. He received the ARRL Bill Orr Technical Writing Award in 2003 and again in 2016.
0:00 Intro
1:52 Ham Radio References
4:49 Background References
5:46 What is ground?
9:23 What is bonding?
15:05 AC Safety Grounding
21:44 Lighting Protection
45:02 RF Management
52:53 Ground System Review
53:56 Mobile Station
54:35 Mobile Power
55:33 Fusing, Ampacity, Voltage Drop
58:29 Power Return Connection
1:01:46 DC-DC Boosters
1:02:24 Bonding in Mobile Stations
1:04:08 Mounting Equipment
1:07:35 Mounting Antennas
1:09:39 Q&A - Věda a technologie
Thank you for this video.
The PLDO component and its usage with an isolated/protected PDU in the shack was a component that I hadn't known about. I knew there was an issue there, and I'd even seen some descriptions of AC to DC power supplies that isolated, to an extent, the AC-side and chassis-ground separately from the DC-out to the radio, but this PLDO component was the missing link in how to make this work.
Now the fun part comes in trying to figure out how to make all this apply to my house, including choice of desk location within the house relative to where I want to place the antenna and the SPGP, with relation to the electrical service ground.
This video must be the most extensive and even authoritive source of info on Grounding/Bonding on UToob.
I'll watch this a few more times, take notes, and incorporate those features that are applicable to my installation.
Currently, I'm floating with my TS-590SG and a 40M Iverted ELL EFHW antenna. Per Steve Ellington, where to Ground an EFHW will make a significant difference in antenna wire current distribution. Hence, I will seriously scrutinize this video and Steve's recommendations.
I've downloaded this video and will refer to it often.
Thank you, Sir, for a very well presented presentation.
73 OM . .
Exellent information packed presentation. Very illuminating and helpful. Thank you. NZ5I
Thanks for this presentation Ward - very clear and helpful.
This presentation doesn't seem to correspond with Mike Holts NEC grounding teaching on CZcams. It seems everyone has an opinion about "proper grounding". ...Am I right?
I also have problems with much of this presentation Their should only be one entry point for everything, including water pipes. A "PAN" bar at the service ground configured in the following way:
Producers go on Left. (outside equipment)
Anode or Ground in the middle
Non producers on the right. (inside equipment)
Everything that enters the building is bonded to the PAN bar, Phone, feedlines, power, water pipes etc. These bonds need to be as short as possible. All other ground rods should be bonded to the PAN bar from the outside of the building.
In a lighting strike current is directed to the Anode or ground. Current from the strike does not flow through to equipment on the non-producers side of the bar, because there is no path to ground. There shall be no other connections to ground in the building other than that that comes back to the PAN bar.
If you run a wire through the house to another ground rod, the wire and all of its connections have resistance. This means there will be a difference in potential (voltage) between the ground rods and current will flow through the building. You never want current from lighting to flow through the building under any circumstances.
Yes the voltage will rise and fall during the strike but if it has no path to ground it will be harmless to your equipment. It doesn't matter how high the voltage gets as long as there is no current flow electronic devices will come out the other side unharmed.
After thorough grounding my house from the AC safety rule perspective (NFPA NEC 70), I installed a lightning protection system (NFPA 780) and then decided to get my ham license so I could have a ground station with Winlink as an email backup. The presenter is correct that these are three different but related sets of requirements/standards. They all concern electro-magnetic equipment but at widely different frequencies with widely differing behavior. If someone is just familiar with one area, the others may have details that don’t seem to make sense. My adequate AC house wiring grounding wasn’t enough for lightning issues. So I proudly added a ‘star’ configured Equipotential Ground Bus Bar. (‘PAN’, although that acronym doesn’t appear in NFPA publications). And then realized the wires were way too long for RF frequencies. So I’m back to redesign again. I’m glad this video looks at all 3. Motorola’s R56 publication addresses all 3 also. BTW I do all this work under permit so it’s inspected by my city/AHJ.
Can multiple ground rods be bonded above ground? (i.e. Lightning conductor exoskeleton around top/sides of house, supporting lightning terminals). Like a Faraday cage.
Question: After screwing the flashing to the table, do you tie it to something? You said it's a "ground plane", so connect the flashing to the RF ground?
Fantastic video, The best video I've seen on this subject. I have a simple HF station consisting end fed antenna , 49:1 UNUN. I'm running a IC-7300, My power supply's DC negative is not tied to mains protective earth. So far nothing except the case of the power supply is tied to earth. During rain the other day I found my (disconnected coax sparking shield to centre conductor, from the wind and rain). My mains protective earth spike is fortunately is directly under my antenna. Rather than banging in a second rod can I tie DIRECTLY the antenna UNUN ground , small chimney mounted mast, radio, to the main service ground rod? I feel like the answer is yes being we tie all ground rods together anyway. Should I then be grounding my power supply negative directly back to that steak or through the case or leave it disconnected? I'm thinking ground loops and potential differences if it has to go through the house wiring. Then I start thinking what about if I connect the usb to my pc thats connected via lan to a switch in another room etc... Thanks!
@W1AL
Some great info in this video. Unfortunately it is a myth to think that connecting a station ground to a ground rod outside the shack is a good idea. If lightning didn't exist, MAYBE. But lightning does exist. And if a strike is close enough, the voltage from the strike travels into the ground up the ground rod and its attached wire, and into your shack, likely frying everything connected to it. Ground is not equivalent to as place where lightning goes to die. The ground can and does get charged when struck by lightning, and connecting your radio and ham gear to it increases the danger dramatically. Lesson? Disconnect any buss bars that may be connected together inside the shack from the exterior "ground rod." Think of it this way: certain appliances come with a third wire (the green, for ground) so that it is properly grounded. In the olden days of ham radio, they weren't. What may have been necessary then (to eliminate charging the chassis of that old radio) is unnecessary today. Your ham rig IS grounded if it has a 3-prong plug. What is true for the garden variety appliance is equally true for the rig. Unless you know of an appliance that requires a ground rod being banged into the ground out the nearest window. I sure don't. If one thinks of the logic and physics of it, it really is simple. Now...RF grounding is another myth. BUT, none of these problems were ever solved (or could be) by running a ground wire from anything to an outside ground rod. First of, running a wire creates an antenna, therefore making any problem worse. Far better to put one's energy into ferrite chokes to resolve RFI than messing with "grounding." This old wive's tale needs to be put to bed. The mixup lies in the wording in the NEC code (that "equipment" must be grounded). That doesn't translate into running ground rods to everything that one plugs into an outlet. Why do ham rigs have a "grounding" post? It is for BONDING as you wisely point out. By the way......I live in FL. Lightning is not DIRECTABLE or CONTROLLABLE. Thanks again for your wisdom on this topic. 73 de Scott, W1AL
I have attended talks by Monty Bateman, WB5RZX -- he has a Ph.D. in Physics and works in lightning research for NASA at Huntsville. He advocates for single point grounding, including radio equipment. Also, Motorola wrote the industry standard practices for grounding at communications sites, and they advocate for it too. Where are you getting the information you're talking about?
I have my 3 antennas connected to a 2 position MFJ switch, one position connects to the radio and the other directly to ground with 12ga copper wire. All antennas and equipment are connected to the same buss bar with that connected to a 12 cu ft galvanized window well and bonded to the house ground. Do you see a lightning problem with this setup when all switches are set to ground?
Hello Ward.
I have a Grounding question. I have a copper pipe for grounding all my radios inside my Shack & all other Ham equipment.
Then connecting it to my outside utility box to my copper bar where all my lightning arrestors are.
From the Copper Bar inside the Utility Box connecting to my Ground Rod buried 9' on the ground. Is it safe to connect all my radios & equipment w/ the lightning arrestors?
Some said it's wrong to put them all together. Was wondering about your opinion about this?
Someone suggested that I need a separate Ground Rod for the Radios & Equipment.
That it does not make any sense connecting the Radios & Equipment w/ the Lightning Arrestors for the Antennas?
It is very expensive to put another Ground Rod because my Ground in the Property is Granite. I had to hire 3x Laborers to Sledgehammer the ground rod for 4 hours. Costing me around $400.00 in Labor per hour.
Stay Safe.
73
Ruben Tiosejo
KD6CWI
Kudos - 73 de 2E0IUI.
Great presentation, not that it matters now but after you were interrupted by the "curator"??? tm~1:00:00, your slides went BSC and everything was very hard to follow because of the distraction . I had to watch that portion over again. I noticed another Ham was adamant about not using a ground fuse due to a sudden loss of your vehicle ground circuit which I find rare in today s cars; thanks for the emphasis on battery monitoring circuits also, I have a 2007 GM truck with a current transformer for the ground wiring and you will screw up your charging cycle by bypassing it. Once again best explanation (class) on station and mobile grounding and protection. 73