Copper Bonded Earthing Electrode

Solid copper is always the best conductor.

Some local codes require multiple ground rods, with an unbroken ground wire between rods,depending on soil conductivity,and CAD(Thermite) welding the wire to the rod(s). Check with the Authority Having Jurisdiction.

The <...resistance...> can be lowered by pouring a road-tanker-full of seawater over the earth pit.

Since you are using chemical earthing,here is a link to a common provider of chemical ground rod systems.

https://www.erico.com/category.asp?category=R2500

There are places,such as the desert,where it is very difficult to produce a good ground to Earth.These chemically saturated systems must be constantly maintained for continuous reliability.

Simply saturating the surrounding area from the surface is not reliable in these cases.It will dry out quickly.

Sadly, several soldiers were electrocuted in Iraq and Afghanistan by ineffective grounding and bonding conditions,esp. in the bathrooms/showers.

The goal of grounding is to provide a single source for all grounds to prevent a differential in potential between any two points.

In a service station all devices lower than 4 ft above ground must conform to Class1 Division 1 hazardous regulations.

There is no limit to the depth of this zone.

The conduits must be sealed at the pumps to the panel and all conductors,including neutral must be broken by the circuit breaker when switched off or tripped.

The work must be performed by a qualified electrical contractor.

"Know safety,No Pain."

"No safety,Know pain."

What does your local codes say?

Often copper clad steel rods are chosen for locations where driving grounding rods is difficult enough that they might bend. Buried (as opposed to driven) pure copper rods are my preference but I live on a fairly large sand bar. Even when one finds a clay layer a post hole digger will still work very well to make a sufficiently deep hole.

Chemical earthing does initially provide a low impedance earthing but far too often the chemical can leach away from the electrode degrading the earthing connection, as this video shows.

It all depends on the local conditions and code standards.

Redfred, the copper-clad rods are commonly used these days for exactly the reason you say, for more effective driving into the soil conditions. But the actual bulk material of the rod is not as big a factor for grounding as the length and diameter of the rod (whatever material) and the composition of its surface layer for current transfer to the soil. The larger the diameter and length of the grounding "surface" the better connection to earth. Clad ground rods will have a current rating, usually coordinated with commonly used grounding cable gauges (e.g., #4/0 Cu or 19-#9 Copperweld) so that the fusing current is similar no matter what material you use.

So the choice of using copper-clad rather than solid copper usually comes down to ease of driving into the soil and lower likelihood someone would want to steal them for the copper content.

Yes, the contact surface area is far more important than what ever material is not in contact with the soil. My mild preference for solid copper comes from an apprehension of too much copper cladding being scraped off at some point in time.

Having driven miles of earthing rods, use copper clad earthing rods of the type that can be coupled together to enable deeper driving. Use the correct joiner consisting of a steel pin and a copper sleeve which is driven over the rods by the action of the pneumatic driver.

Have driven 2.4m earth rods up to 24m into the ground to get the required value of earth continuity. All rods should be connected to the earth cable with a thermite welded bond. Some areas require the use of steel only with steel flat strip welded to the steel rods. Particularly in areas where copper may set up a cathodic reaction with steel underground pipes.

To get a better earthing effect bentonite is used as a trench filler in high silicon soils and salt can be added to the bentonite to make it more conductive but don't overdo it.

Remember to make sure you know where underground services exist. It would be no good driving an earth rod through a gas line or worse still the local metro.

The National Electrical Code (USA) specifies a resistance of less than 25 ohms to ground,referenced to at least 2 different testing ground rod points.

Imagine a sphere equal in radius to the depth of the ground rod and you will have a mental picture of the theoretical grounding volume.

Testing is performed by using at least 2 other ground rods,spaced equilaterally from the main ground rod and each other, at about 10 ft. with no other connections to the main grounding rod allowed(water,gas pipes,et.)

Some contractors have been known to cheat by cutting off the ground rod when the ground becomes hard to penetrate,or simply to save money, but the inspectors can tell and there is a $$ penalty for doing this,as well as being put on the inspectors' "radar". Every detail of all of your work will be minutely inspected from then on.

They can go back as many years as they desire and check previous installations,so past sins will come back to haunt you.

Rocky soils or other hard to penetrate areas are allowed to bury a ground rod on a diagonal or horizontally as long as it passes the testing protocol and the common sense judgement of the inspector.

Grounding and bonding are more complicated that appears at first glance to the untrained and unqualified.

Chemically modified earth needs to be periodically maintained and checked to prevent a decrease in effectiveness,which I mentioned in my previous reply.

As usual,the local AHJ (Authority Having Jurisdiction) has the final word on everything,so check with the local code authority.

I’ve used copper bonded electrode rods and found them very reliable with great conductivity and durability. Helpful blog!