Earthing Systems
Earthing systems, also known as grounding systems, are one of the most important aspects in the installation of electrical systems. Their correct implementation guarantees not only the safety of people and equipment, but also the stability of the electrical grid.
What is an Earthing System?
EARTHING SYSTEMS
Design and installation service for earthing systems
At Procainsa, we have been designing and installing earthing systems for industrial, energy, and critical infrastructure facilities for over 30 years. Each project starts with a soil resistivity study and adapts to the applicable regulations — REBT, IEC 60364, or sector-specific ones — to guarantee a durable and safe solution.
What does our service include?
From the preliminary study to commissioning, we manage all project phases:
- Soil resistivity study
- System design
- Electrode installation
- Verification and measurement
- Technical documentation
Sectors we work in
We have experience in earthing projects in particularly demanding environments:
- Refineries, tank farms, and petrochemical plants
- Wind farms and photovoltaic plants
- Data centers and telecommunications
- Industrial and tertiary buildings
- Port infrastructure and marine environments
Types of Earthing Systems
Protective Earthing System
Functional Earthing System
Combined Earthing System
Applicable Regulations for Earthing Systems
The design and installation of an earthing system must comply with local and international regulations. Some of the most relevant are:
- IEC 60364-5-54: International standard detailing earthing requirements in low-voltage electrical systems.
- NFPA 70 (National Electrical Code): Applied in various regions for safe and efficient installations.
- Low Voltage Electrotechnical Regulation (REBT): Specific regulation in Spain for low-voltage electrical installations.
Types of electrodes for earthing systems
Star-plates and plates
Earthing systems using star-plates, plates or similar are installed in artificial pots based on opening a pit or trench of 2 to 3 m³ and filling it with topsoil and other additives to reduce soil resistivity (Ledoux treatment).
The electrical earthing resistance values obtained in these installations can be considered acceptable for high resistivity soils. Due to the lack of soil compaction, these values tend to improve some time after installation, remaining stable for a period ranging from 5 to 10 years.
Conventional rods or stakes
Rods or stakes are the most widespread earthing system due to their easy installation. Considering that their introduction is done by driving, the earthing resistance values are obtained immediately, and are better than those of the plate system. However, these values should be understood as exclusively circumstantial, since due to the effect of corrosion on steel, the rate of loss of initial resistance is very rapid, and even more so when the quality of copper or zinc coatings has been reduced or deteriorates during the driving process.
Rigid graphite electrodes
The configuration of the rigid graphite electrode in the form of an anode, with a filler activator-conductor to improve intimacy with the ground, makes this earthing system highly reliable. Being an electrode made entirely of graphite, it is not intensely affected by corrosion, unlike metals.
Regarding remote earthing resistance values in soils of different resistivities, their behavior is very similar or even better than that of star plates, and much better than conventional rods. In parallel, the evolution of these values over time is unbeatable given their low corrosion wear rate, and therefore their service life is in principle unlimited compared to traditional systems. Thus, the very nature of the electrode, its dimensions, and the surrounding conductive activator mean that it does not require any maintenance (watering or mineralization) as is so frequent in other systems.
Due to all these characteristics, the rigid graphite electrode is ideal for shallow and deep earthing systems as it guarantees long durability and more than acceptable performance.
Zinc stakes
Zinc stakes are an ideal solution for cathodic protection against corrosion of earthing systems when these are made of galvanized steel conductors. They also prevent the galvanic couples so frequent in earthing systems of steel structures (buried tanks, or bases of above-ground tanks) against bare copper conductors.
Recent MIE-ITC-01 and MIE-ITC-02 standards mandate the installation of earthing systems with galvanized steel conductors (or insulated copper) and Zinc stakes in refineries and fuel storage tank farms. These technical considerations are extendable to installations such as gas stations (MIE-ITC-04), chemical plants, etc.
The main characteristics of these stakes are:
- Good performance due to their low electrical resistance.
- Large dispersion surface and good intimacy with the ground as they come with a bag filled with a bentonite-based activator-conductor.
- Easy handling and easy installation by any user.
- Possibility of determining their degradation status without unearthing them.
Picron Electrodes
PICRON electrodes have been designed for high-performance earthing systems, especially for deep or semi-deep earthing, in marshy terrains, with high water tables (deltaic areas) and even in very aggressive waters (marine environments or directly in seawater), for high and low voltage electrical installations, lightning rods, and IT or robotics equipment.
PICRON electrodes can be considered the earthing system with the highest guarantee and stability on the market.
Their main characteristics are:
- Unlimited duration (>30-year life), due to minimal degradation by corrosion.
- They can be used as single electrodes or chain electrodes, for installation in vertical boreholes from 160 x 3000 mm diameters, or they can be installed directly deposited on marine sediments.
Zero maintenance, as they do not require periodic watering to establish their conductivity
Earthing for building slabs
Frequently asked questions about earthing systems
What is the difference between 'puesta a tierra' and 'toma de tierra'?
‘Puesta a tierra’ and ‘toma de tierra’ are two terms that designate the same concept: the electrical connection between an installation and the ground to dissipate fault currents and protect people and equipment. The difference is solely terminological and geographical.
‘Puesta a tierra’ is the predominant term in Spain and is included in the Low Voltage Electrotechnical Regulation (REBT). ‘Toma de tierra’ is used as a synonym in some regulatory contexts and is more frequent in certain Latin American countries.
In practice, both expressions refer to the same system: buried electrodes, protective conductors, and equipotential connections that ensure the safety of the installation.