When designing and carrying out a grounding installation, various situations can arise such as lack of space, high resistivity or aggressive soil which can make it difficult for the grounding resistance to attain the required values.

At conGraph solutions we have developed conGraph GND-20 which:

  • Reduces the grounding resistance value
  • Reduces the size of the installation
  • Provides permanent performance that requires no maintenance
  • Protects the electrodes against corrosion
  • Is a calculation-based solution
  • Is an environmentally friendly product



Access our calculator to determine the grounding resistance value using conGraph GND-20Only a few initial details are required:

The calculator will get the estimated grounding resistance value.

  • It will also work out the number of bags of conGraph GND-20 necessary to achieve the required grounding resistance value.
  • It is an intuitive and easy to use application.
  • It will help in the completion of the design of the grounding system and calculate potential reductions in the size of the facility.

conGraph GND-20 is a combination of cement based and carbonaceous materials which conducts electricity and acquires a high compressive strength.

Given its properties, it is used to reduce the ground’s resistance to electrical installations and increase the longevity of the installation by offering a permanent solution.

The concept of conGraph GND-20 is not to change the properties of the ground itself but to significantly increase the active area of the grounding system’s conductive elements which, in turn, are protected against corrosion.

This enables a reduction of between 30% and 60% in the grounding resistance value when compared with a traditional design.

conGraph GND-20 complies with the UNE EN IEC 62561-7 “Requirements for earthing enhancing compounds”.

Supplied in 20 Kg. laminated paper bags.

For correct application and optimum product performance, we recommend mixing conGraph GND-20 with water at a ratio of 7.5 – 8 liters per 20 Kg. bag in order to attain a sufficiently dense consistency for easy application.

After mixing the product with water, the resultant slurry adheres completely to the electrode and can fill any gaps between the electrode and the soil.

conGraph GND-20 solidifies 24 hours after application in the absence of unfavourable weather conditions.

  1. Drill a hole in the ground. Minimum diameter 65 mm (2½“).  Minimum depth 2 m (6’6’’).
  2. Mix conGraph GND-20 with water.  Use from 7.5 to 8 liters of water (2 US gallons) per 20Kg. bag.  Do not use salt water.
  3. Use the number of bags of conGraph GND-20 recommended by the Table (see table) or the CALCULATOR.
  4. Pour conGraph GND-20 into the hole.
  5. Place the electrode in the center of the hole and insert it.
  6. Wait at least an hour before filling the top of the hole with conGraph GND-20 powder or native backfill.
Diámetro de la perforación (mm)
Hole Diameter (in)
Profundidad Depth   60     80   100 120 140 160 180 200 220 240 260 280 300
(m) (ft) 2.4 3.1 3.9 4.7 5.5 6.3 7.1 7.9 8.7 9.4 10.2 11.0 11.8
2 6.6 1 1 1 2 2 3 4 4 5 6 7 8 9
4 13.1 1 2 2 3 4 6 7 8 10 12 14 16 18
6 19.7 2 2 3 5 6 8 10 12 15 17 20 24 27
8 26.2 2 3 4 6 8 11 13 16 20 23 27 31 36
10 32.8 2 4 5 8 10 13 16 20 24 29 34 39 45
  1. Dig a trench of suitable dimensions.
  2. Mix conGraph GND-20 with water until it forms a paste. Use from 7.5 to 8 liters of water (2 US gallons) per 20 Kg. bag.  Do not use salt water.
  3. Pour a layer of the mixture up to a minimum height of 100 mm (4”).
  4. Place the conductor on the layer of conGraph GND-20.
  5. Pour conGraph GND-20 up to a minimum height of 150 mm (6”). Ensure that the conductor is completely covered.
  6. Wait at least one hour before filling the trench with native backfill.

conGraph GND-20 is an environmentally friendly product which enables a reduction in the grounding resistance value thereby helping to protect the safety of people, property and equipment.

conGraph GND-20 offers permanent performance and is maintenance free. It is not necessary to moisten the ground periodically and the electrodes are protected against corrosion.

conGraph GND-20 is a tested calculation-based product.

  • Reduces the resistance value of the grounding system.
  • Attains a high compressive strength after setting. It protects the metal conductors from theft.
  • Reduces the size of the installation.
  • Is a permanent solution, the grounding resistance values remain stable.
  • Protects the electrodes against corrosion.
  • Absorbs electrical surges.
  • Is maintenance free.
  • Is environmentally friendly.