Earthing equipment
Auxiliary equipment of cathodic protection systems / earthing equipment:
For cathodic protection stations with rectifier transformer, a separate earthing system is considered. The earthing system of the cathodic protection station consists of the following components:
1- Two 1/2 meter earthing rods with a diameter of 15 mm (earthing rods are made in two types of all copper and copper coating, which are used in accordance with the standards of cathodic protection system of all copper type). 2- Steel tip. 3- Mediator. 4- Cable clamp. 5- Steel impact head. 6- Communication cables
According to the surrounding soil and the specified resistance value of the earthing system (according to the design circuit), the number of relevant earth wells is different and the number of earth wells must be increased to achieve the specified resistance value.
Earthing system installation method
The installation steps of the earthing system are as follows:
a) First, the tip and head of the steel impactor is tied to the first earth rod and hammered into the ground.
b) After running the first rod in the ground, open the impact head and connect the intermediate, then connect the second rod and connect the impact head again and hammer the second rod into the ground as before.
c) Dig a pit of 500 x 500 x 500 mm around the earth rod and level and compact the bottom of the pit.
d) After passing through a 2-inch PVC pipe, harness the earth cable in the bottom of the pit and place the concrete mold made according to the following plan inside the pit. After leveling the concrete form, return the excavated soil to the pit.
e) Install the earth cable with a clamp on the earth rod. Finally, make and paint a metal valve according to the drawing below and install it on the foundation of the earthing system.
It is very difficult to hammer the earth bar in hard and rocky ground. To solve this problem, first dig a pit to reach the surface of soft soil, then implement the earthing system according to the mentioned steps. Considering that the specific resistance of the soil is high in rocky and hard lands, to reduce the resistance of the earthing system, use charcoal and salt for the earth well around the earth rod.
Executive requirements:
If possible, it is better to implement the earthing system in places with low resistance or in the vicinity of moisture (such as: garden, soft ground, etc.).
Usually, the earthing cable is chosen without a cover, which is used due to the reduction of the total resistance of the earthing system.
The implementation plan of the earthing system according to IPS-TP717 standard is shown below.
