I'm seeing Mike's battle

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Gary11734

Gary11734

Senior Member
Location
Florida
Going through this since I became an electrician was always a battle.

Sometime in the eighties, I finally got the wording so I knew when the code said, "grounding" and sometimes said "Grounded", I had it down. Then, somewhere they changed those meanings to now something that is not exactly the same as then.

The industry looks like its finally got their act together and defined the terms better. Now, if they would just stick to them I wouldn't have to relearn this stuff all over...

Once we figured out those grounds rods in the back yard at the service were for lightning strikes and not tripping breakers, the rest got easier real fast...
 
J

JPinVA

Senior Member
Location
Virginia
gadfly56 said:
So, by your explanation, if I had no electric service to my house of any kind, I'd still have to ground the rebar in my foundation?
Click to expand...

Electrical service is not necessarily relevant to the need for a ground. It's the existence of anything that can build up a charge in isolation to ground, or in isolation from other such devices. If we have wires and motors and an assortment of other like devices in our house...then yes, they can build up charges even with no electrical service to the house.

It can come from lightning, or even from the presence of a charged cloud over your house. A positive charged cloud over your house, will induce a negative charged "mirror" image of charges on the ground below. Lightning is what occurs when the air gap threshold between cloud and ground is exceeded. A strike attempts to equalize charges. If the air gap threshold isn't exceeded...no lightning occurs...but the charge build up is there...or moves along with the cloud. And lightning between clouds establish magnetic fields that couples with things in the house

Some belt driven motors can create substantial static build up...enough for a resulting spark to start a fire.

Charges are all around us. We only notice their existence when something happens. That bite of static discharge between hand and door knob. The crackle of static as we pull apart socks fresh from the dryer. And yes...that smack of lightning during a thunder storm.

Basically, we want to make sure that anything in our house that can build up charges has a way to discharge those charges in an orderly manner. Bounding all this stuff together, and then making a connection with ground, goes a long way to achieving the goal.
 
Sahib

Sahib

Senior Member
Location
India
More than grounding and bonding in a building, certain objects such as lamp posts may require additional protection of bonding: suppose a person is in touch with a metal lamp post, properly grounded, when the phase conductor shorts to lamp post. The person would be subject to a shock voltage for a duration till the associated protective device cuts off supply to lamp post. This could be dangerous. So in such condition it may be prudent to provide a small earth mat bonded to lamp post.
 
mbrooke

mbrooke

Batteries Included
Location
United States
Occupation
Technician
GoldDigger said:
And if implemented incorrectly it can actually increase the risk oof step potential injury.

Sent from my XT1585 using Tapatalk
Click to expand...

I think you just created a new thread :D

But you can explain it here if you think its fitting. Honestly, you have peaked my interests.
 
A

Adamjamma

Senior Member
Location
Jamaica and london
If one makes a mat or grid at the base of the lamp for grounding, yet does not bond it to the rest of the installation, then one in theory could have two areas of different voltage in the ground... but the same is theorized about failing to bond the ground outside the dairy barns to the floor of the dairy barns...
i thin’ current best practice is if you have steel in a driveway or a sidewalk or a stairs, then you should bond it to the rest of your grounding system to keep the potential equalized as much as possible.
But, I could also be mistaken as this section seems to constantly be changing in how it is interpreted. I have seen some claiming that when we bond Antennas and Light Posts to our grounding systems all we do is increase the way lightning can enter our structures.
I am so confused about it that I am just at the point of.. if the steel is there and not connected somehow to ground, it needs connected to ground..lol..
 
G

Galt

Senior Member
Location
Wis.
Occupation
master electrician and refrigeration service tech.
In my experiences over the years lightning does the most damage when it hits something made of conductive material then jumps to something that is well connected to the neutral. everything made of metal on a farm should be connected with a wire one giant piece of conductor no jumping.
 
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