Created by: Glen Zhu | Updated Date: November 27th, 2023
Petrol stations are generally located on the side of the highway, mostly in open areas of isolated buildings, vulnerable to lightning strikes.
Another feature of petrol stations is they store and dispense large quantities of highly flammable substances like gasoline and diesel. These fuels can easily vaporize and form a flammable mixture with the air, making them highly susceptible to ignition.
A comprehensive lightning and surge protection system can be the solution.
Lightning strikes events affect petrol stations in various aspects. There are several main threats:
Direct Strikes: Remote location and open-air design increase the likelihood of lightning damage. There is not enough protection zone against the effects of lightning.
Lightning Electromagnetic Pulse: Generally, the 380V AC power supply lines of gas stations are connected by overhead open wires to the station area and then buried underground and introduced into the building. In rural areas and mountainous areas, necessary grounding system is ignored. Therefore, it is very vulnerable to lightning wave intrusion and lightning electromagnetic pulse.
Anti-flash: Telephone lines, monitoring equipment and other weak power lines introduced into the petrol station are usually also introduced by the outdoor overhead wires, and usually do not install a special signal surge protector to do anti-flash measures.
Static Electricity: Fuel dispensers or fuel nozzles failed to ground or poor grounding, leading to high resistance. And the breathing valve of the petrol station is not connected across or the resistance value of the cross-level is high.
With the widespread adoption of gas-powered automatic vehicles, there is an increasing demand for fuel. However, petrol stations could face a significant risk of explosions due to lightning strikes, which can ignite flammable liquids or vapors, leading to substantial losses.
To mitigate these risks, strict regulations and guidelines are in place to ensure the safety of petrol stations.
These measures include the installation of necessary lightning rods to protect petrol station buildings, as well as the implementation of proper grounding and bonding systems to prevent damage to under-earthed systems. Additionally, reliable surge protective devices are utilized to maintain the power supply system and terminal devices in the petrol station.
Making a risk assessment is helpful for the whole installation of protection. The lightning protection zone (LPZ)concept complies with IEC 62305-4:2010 and regulates how to plan, implement, and monitor protection measures.
The level of protection should also be based on the geographical location of the petrol station, then the type of surge protectors can be determined. (As shown in Figure 1)
Figure 1 – Petrol station with lightning protection system, earth-termination system, equipotential bonding, and surge protective devices
Physical damage is the most evident damage caused by lightning strikes. Direct lightning strikes can cause fire to the entire structure and even blow off the building. As a public infrastructure, petrol stations must be installed with an effective lightning protection system.
The canopies of petrol stations are the major areas vulnerable to direct lightning strikes. Modern petrol stations often use a combination of steel and concrete or other metal materials for their top structures. Its conductivity helps lightning currents travel through down conductors in columns to the earthing system so that overvoltage dissipates to the earth.
Convenience stores also need lightning protection. Free-standing lightning rods can be carried out on the roof of the store to against possible direct lightning strikes.
The fuel dispensers are located underneath a projecting metal roof and are thus protected against direct lightning strikes (Figure 1).
To ensure an effective lightning and surge protection system, an earthing system plays an important role in offering a low-resistance pathway for electrical current to flow into the ground, thereby preventing damage to electrical equipment and electrical shock.
The petrol station has two critical electronic systems that are very sensitive and need dedicated earthing: the Automated Tank Gauging (ATG) system and the Power Supply System (UPS).
The Automated Tank Gauging (ATG) provides real-time monitoring and management of fuel tanks, ensuring accurate inventory control and enhancing overall safety.
This system is usually backed up with a regulated power system or UPS because any switching surge, lightning strike, or unregulated power supply can damage it.
To protect this ATG and UPS there must be separate earthing and lightning protection systems. The fuel dispensing machines are also automated electronic systems with regulated power supply.
A well-designed earthing system for petrol stations is:
The ground ring electrode or ground loop must be supplemented by one or more grounding electrodes for safety. The number and size of electrodes depend on the station’s electrical load and the soil resistivity.
Earthing at petrol stations must have cathodic corrosion protection and spark gaps in hazardous zones. According to IEC 62305-3, it regulates the earthing system should have an earth resistance lower than 10 ohms.
Figure 2 – Basic principle of impressed current cathodic protection
Lightning damage occurs when current flows due to the difference in potential at two different locations. The difference in potential at the two locations can damage your electrical systems. Equipotential bonding is an important aspect of maintaining an equipotential zone within the petrol station.
The electric potential difference happens because of the presence of electric charges, specifically electrons, in a conductive material.
The flammables in petrol stations can take up the charge from the lightning strike. These charges are often not released within the strike neutralization period and remain in the material. Once the surroundings are neutralized, the difference in potential causes an arc called the Secondary arc, which can result in the fire of the flammable liquid.
Therefore, to ensure that the charges are neutralized and for protection of the different operating systems equipotential bonding and earthing must be provided according to IEC 62305.
All metallic constructions, metallic pipes, fuel tanks, etc. must be bonded and connected to the earth termination system. This prevents the buildup of static electricity and eliminates the risk of sparks that could lead to a fire or explosion in the presence of flammable vapors.
A lightning strike always carries an electromagnetic pulse (EMP) that creates a momentary power surge. While the surge only lasts a short time, it has the potential to carry a large amount of voltage into the circuit, making all appliances connected to an electrical system susceptible to over-voltage damage.
Advanced electronics are more susceptible since they have smaller components that are more sensitive to higher voltages.
Surge protection for petrol stations is classified into 3 levels:
The first level of power protection. In the main distribution box of the gas station, a three-phase switching modular power surge protector is installed behind the main circuit breaker (fuse) and in front of the leakage protector, which is used for all electricity consumption in the entire gas station.
The second level of power protection. Install power surge protectors for all IT equipment in the distribution box of the computer room and for fuel dispensers.
The third level is signal protection. Install signal surge protectors to protect the telecommunication and data transmission of ATG system, POS system and CCTV system.
Many telephone lines are introduced overhead, and lightning waves can easily enter through the telephone lines and destroy the telephone set. Therefore, it is necessary to bury the telephone line through a metal pipe in the ground before the telephone line enters the room. The end of the metal pipe should be connected to the ground pole and install a separate telephone lightning arrester.
Gas stations are connected to the local electrical grid, receiving power supply from the utility company. This connection provides the primary source of electricity for the station.
Some gas stations use Uninterruptible Power Supply (UPS) systems to provide temporary power during brief power interruptions. UPS systems offer a short-term power source, allowing essential equipment to operate until the backup generator starts.
Type 1 Surge Protective Device SPD FLP25 series are installed in the power cabinet. A specific model should be adopted for a suitable network system.
Equipment in the forecourt (like petrol price display) has an LED screen to show real-time price updates and allow remote visibility. Due to the location of entry and electricity requirement, Type 2 Surge Protection Device SPD SLP40-275/2 or SLP40-275/1+1 to prevent direct strike.
Fuel dispensers are connected to electrical equipment (display panel, keypad, and payment terminal), and they are protected for the location under the metal canopy against lightning strikes.
Attention should be paid to protecting the power lines from the entrance point to the fuel dispenser electronics, so we need to install Type 2 Surge Protectors SLP40-275/3+1 or SLP40-275/4 at the entrance points of the lines into the petrol station building.
Signal systems in petrol station are crucial to control and monitor the fuel management, payment terminals and communications. To prevent the loss of crucial data and ensure the optimal functionality of each system, considering signal Surge Protection Devices (SPDs) is a wise choice.
POS system is essential tools for businesses to process customer transactions efficiently, fuel dispensers and convenience stores in petrol stations are using this system to make payment.
A typical POS system includes a computer, cash register, barcode scanner, receipt printer, and software that allows businesses to track sales, manage inventory levels, and analyze customer behavior.
Modern POS systems are often cloud-based, allowing businesses to access their data remotely and update information across multiple locations in real time.
Power surges can occur due to lightning strikes, electrical faults, or sudden power outages, and they have the potential to damage POS equipment, leading to data loss or payment failure.
Automated Tank Gauging (ATG) systems consist of sensors, probes, and a central monitoring unit. ATG systems use sensors and probes installed inside the fuel storage tanks. The sensors continuously collect data about the fuel level from inside the tanks. The collected data is transmitted to a central monitoring system via wired or wireless communication methods.
Figure 3 – The principle of ATG system
This communication can be done in real-time, allowing instant access to tank information Operators can easily control the inventory fuel and monitor the change of parameters of each tank (like temperature, water presence, and fuel density).
The failure of the ATG system will affect the complete operation of the petrol station, the best way is installing surge protectors at critical points within the ATG system, such as power supply lines and communication interfaces. Surge protectors can absorb excess voltage and prevent it from reaching the sensitive components.
Many petrol stations are equipped with closed-circuit television (CCTV) systems for security and safety purposes. Cameras are placed in different locations to control and monitor every activity in petrol stations.
A typical CCTV system includes cameras, video recorders (DVRs/NVRs), monitors, and cables. Modern CCTV systems may also feature IP cameras, which can transmit video data over the internet.
The cameras are connected to a central monitoring or recording system through cables (such as coaxial or Ethernet cables) or wirelessly (using technologies like Wi-Fi) to transmit videos.
Ensuring the proper functioning of CCTV system is crucial to prevent unfavorable outcomes. Lightning strikes, for instance, can lead to data loss, and the potential loss of vital evidence can be highly problematic. Installing signal surge protectors plays a significant role in preserving essential evidence when unforeseen circumstances arise.
FRD series are the SPD for signal, data, and telecom RS485, RS422, RS232. COAX-BNC/FM protects video transmission.
PoE SPD (DT-CAT 6A/EA) protects sensitive data-processing equipment connected to a POE++ (Power over Ethernet) network from transient over-voltages.
Petrol stations are exceptionally susceptible to lightning strikes because of the presence of flammable liquids. Employing professional lightning and surge protection has emerged as the most effective solution to ensure the safety of both the premises and the people frequenting these locations.
LSP’s reliable surge protection devices (SPDs) are designed to meet the protection needs of installations against lightning and surges. Contact our Experts!
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