Created by: Glen Zhu | Updated Date: December 22nd, 2023
Light-emitting diodes, commonly known as LEDs, has found ubiquitous use across all sectors supplanting traditional lighting systems in contemporary society due to its inherent qualities of energy efficiency, longevity, and versatility. Yet, despite the advantages mentioned above, the highly integrated electrical components and systems of LEDs make them more susceptible to damage under certain conditions.
Lightning strikes and transient overvoltages emerge as two primary damaging sources that can inflict significant detriment upon LED systems. This blog delves into the complexities of transient surges and explores the significant aspects of surge protection for LED lighting systems.
A surge refers to a sudden, brief spike in voltage above the designated level in the electrical circuit. The spikes, also known as transients or power surges, can be caused by various factors, including lightning strikes, switching operations on the power grid, circuit overload, or damaged wiring and circuits. The increase in voltage can happen very quickly, typically within a few microseconds, and it is often characterized by a rapid and transient spike in electrical potential.
When the LED lighting lamps or the systems encounter surges within the electrical circuit, the excess voltage travels through the connected equipment within the system, causing irreversible damage to the entire lighting system.
Here are potential outcomes that surges can have on LED lighting systems:
LED Driver Damage: LED lighting systems typically include electronic components like LED drivers, which regulate the voltage and current supplied to the LEDs. Surges can damage these drivers, leading to malfunctions or complete failure of the LED fixture.
Reduced Lifespan: Continuous exposure to surges can contribute to a shortened lifespan of LED bulbs. The internal components, including the LEDs themselves, may degrade faster than under normal operating conditions.
Color Shift: Surges can affect the color stability of LED lights. LED color temperature and brightness are carefully calibrated, and voltage fluctuations can result in color shifts or uneven illumination.
Flickering or Flashing: Surges may cause LED lights to flicker or flash intermittently, which not only affects visual comfort but can also be a sign of internal damage to the LED system.
Increased Heat Generation: Voltage spikes can lead to increased heat generation within the LED fixtures. Over time, elevated temperature can contribute to thermal stress on the components, potentially causing long-term damage.
Surge protection for LED lighting systems varies greatly due to their operation in diverse industries and settings, each presenting distinct power supply conditions and surge loads.
Consequently, it is recommended that customized surge protection solutions for every LED lighting system be implemented, following expert guidance and tailored to specific requirements.
Dirty power refers to an irregular and distorted electrical power supply that deviates from the standard sinusoidal waveform associated with clean and stable power, which can result in various abnormalities, such as voltage fluctuations, harmonic distortions, spikes, and other unwanted elements in the electrical waveform. The irregularities can stem from various sources, including electrical grid issues, fluctuations in demand, and the operation of certain electronic devices.
Voltage fluctuations in dirty power can lead to inconsistent voltage levels, impacting the stability of the electrical supply. Harmonic distortions introduce additional frequencies that are multiples of the fundamental frequency, creating a non-ideal waveform. LED drivers and power supplies may struggle to effectively filter out these harmonics, leading to increased energy consumption, overheating, and potential damage to the LED system.
Power surges and spikes, often present in dirty power, pose a considerable threat to LED lighting systems by causing damage to electronic components like LED drivers and chips, consequently shortening the overall lifespan of the lighting system. Compulsory surge protective devices are essential for LED drivers as they serve as the heart of the whole system.
Dirty power also introduces electromagnetic interference (EMI), generating electrical noise that can disrupt the proper functioning of LED lighting systems, which can affect the color accuracy and uniformity of LED lighting. LED systems rely on precise voltage levels for consistent color temperature and illumination. Dirty power may cause color shifts and uneven lighting, compromising the visual quality of the illuminated space.
To mitigate the impact of dirty power on LED lighting systems, the implementation of power conditioning devices becomes crucial. Voltage regulators and surge protectors are instrumental in stabilizing the power supply, filtering out harmonics, and sustaining a clean and consistent electrical environment for optimal LED performance and longevity. Regular maintenance, monitoring, and prompt identification of power quality issues are essential practices to preserve the reliability and efficiency of LED lighting systems.
Figure 1 – Clean electricity vs. Dirty electricity
Common mode surge and differential mode surge are critical considerations in safeguarding LED lighting systems from potential electrical disturbances. Common mode surges occur when an elevated voltage affects both the live and neutral conductors simultaneously, creating an imbalance with the ground. The surges can induce harmful currents in the conductive paths of LED systems, posing risks to electronic components. Mitigating these risks involves proper grounding practices and the use of surge protection devices (SPDs) specifically designed for common mode protection.
On the other hand, differential mode surges result from an elevated voltage between the live and neutral conductors, causing a potential imbalance within the circuit. LED systems, particularly their drivers, are more susceptible to surge issues due to their complex electrical design. To address this, industry standards like IEC61000-4-5 and IEEE Std C62.41.2 regulate surge protection levels for LED drivers. Outdoor LED usage demands specialized surge protection circuitry, typically composed of MOVs (metal oxide varistors) and GDTs (gas discharge tubes).
In electromagnetic compatibility, both surge common mode and differential mode suppression are very important. Interference from surge common mode or differential mode signals can affect equipment for a variety of reasons, such as ground potential differences, incorrect grounding, and failure of surge suppression circuits.
Therefore, in the design of electronic circuits, it is necessary to reduce these interferences and improve the reliability and stability of the equipment by means of suitable suppression methods, especially differential-mode suppression methods. At the same time, for applications that require data reception on differential signal lines for high-speed transmission, the proper selection of differential mode suppression methods is even more critical.
Figure 2 – Common mode surge and Differential mode surge
In the lightning protection zone (LPZ) concept, lightning protection is practiced according to the level of threat posed by lightning. LPZ concept divides lightning protection into distinct areas based on the varying levels of lightning threat. The zones are designated to manage and mitigate the risks associated with lightning strikes.
Specifically, outdoor areas are categorized into LPZ 0A and LPZ 0B. LPZ 0A designates outdoor spaces directly threatened by lightning strikes and lacking specific lightning protection measures. These areas are considered more vulnerable to lightning-related risks. On the other hand, LPZ 0B refers to outdoor environments where the risk of lightning strikes is comparatively lower, and some level of protection is implemented to mitigate potential damage.
Figure 3 – Outside of the lightning protection zone diagram
For LED lighting lamps and systems installed at LPZ 0A areas, it is compulsory to install type 1 or combined type 1+2 surge protective devices to the switchgear connected to the lighting systems. Failure to do so can lead to frequent lighting malfunction. To have the whole system better protected, it would be recommended to apply spark-gap-based surge arresters to the circuits involved to reduce extra currents and voltages as much as possible.
Figure 4 – Discharge partial lightning currents via lightning protection for LPZ 0A LED mast lights
The LED outdoor lighting is more vulnerable to be impacted by lightning currents and surges than lighting installed within buildings due to the exposed nature of outdoor installations. Even when situated in a lightning protection zone 0B (LPZ 0B), despite maintaining a safe distance from lightning-prone installations, such as LED mast lights within a protected building, there is a risk of flashover during lightning strikes, posing great threats to LED mast and bulb surge protection. The use of multiple type 2 surge arresters is suggested to minimize damage to the lighting system.
Figure 5 – LED mast lights in LPZ 0B at risk from partial currents
In real-world applications, all lighting systems and components are installed in the areas of LPZ 0B. If the circumstance can’t be met with the standard, lightning rods should be installed to protect systems from potential lightning currents. And type 2 surge protectors are used for this kind of condition.
Figure 6 – LED outdoor lights lightning protection zone 0B
When installing outdoor lighting on the metal facade of a building, utilizing the facade as a natural conductor is possible. This is contingent upon the facade completely enclosing the building, having no unduly wide openings, featuring connections proficient in carrying lightning currents, and being systematically linked to the earth-termination system every 5 meters. Under the specified conditions, it is reasonable to assume that surge protective devices can effectively manage loads, demonstrating comparability with those associated with LPZ 0B.
Figure 7 – LED lights on the building’s metal facade meet lightning protection standards without the need for observance of separation
LED mast lights, frequently employed in public streets and walkways, are notably vulnerable to a variety of surge loads, particularly those induced by lightning strikes. Despite their advantageous metal composition, offering mechanical strength, electrostatic discharge resistance, and heat resistance, there are inherent disadvantages during close-range lightning events. Street lights commonly fall into protective class II, featuring double/reinforced insulation, or protective class I with a protective conductor terminal.
In the context of cable networks, impedances is critical in determining the light protection class for LED mast lights. In TN systems, prevalent in these installations, rapid circuit disconnection is imperative. To achieve the required switch-off time, especially when considering loop impedances, the utilization of fully insulated versions of both conductors and lights becomes instrumental.
In the event of a lightning strike on the lighting mast, although the earthing impedance is elevated, the potential of the masts and lights far surpasses the withstand voltage of the upstream devices. This leads to the occurrence of flashover from the mast to the upstream devices.
Figure 8 – Mast light housing flashover to mains voltage upstream
During lightning strikes, a radial potential gradient forms around LED mast lights, creating a voltage disparity with the remote reference potential, which can surpass the withstand voltage of upstream devices, leading to flashovers. Deploying surge protective devices with gas discharge tubes strategically placed in the functional bonding conductor between the mast and N/PEN conductor mitigates these risks. For instance, data indicates that such surge protective devices have demonstrated a 90% reduction in lightning-induced failures and a significant decrease in downtime due to electrical faults.
Figure 9 – 6 A gG fuse blows, disconnects the short circuit from lightning current
Surge protective devices not only prevent accidental energization but can guarantee safety by blowing the fuse after an overload when it is needed, averting dangerous electric shocks and corrosion currents.
To further diminish the risk of electric shock, manipulating the earth surface potential around LED mast lights proves effective. Installing an earth rod connected to the LED mast light or an earthing conductor above the cable route significantly reduces the likelihood of dangerous electric shocks in the vicinity of LED mast lights. Real-world case studies have demonstrated a 75% reduction in electrical incidents after implementing such earth potential manipulation strategies.
When choosing surge protection devices, it is advisable to prioritize din rail mounted surge protectors for enhanced efficiency.
For the scenario described above, type 1+2 surge arresters like FLP12,5-275/3S+1 and type 2 surge protectors like SLP40-275/3S+1 are recommended. Both devices hold TUV-Rheinland certification. Surge protective devices from LSP, with unique pluggable design and high withstand voltage, they are reliable and effective in protecting lightning and
To ensure enduring and efficient lighting, it is recommended to install an LED Surge Protector on each LED light. They are characterized by a compact design, and are easy to install in any luminaire.
A singular LED light needs the integration of a surge protector, and this necessity extends beyond the well-being of the physical infrastructure. It is important not only for the sustained functionality of the lighting fixture but also for the smooth progression of activities and the safety of individuals involved.
In the LED light remote control line, the installation of a signal surge protector is crucial. With a notable example being the FRD2 series, the selection of the appropriate model depends on a meticulous assessment of the power supply and voltage specifications inherent to the existing system.
For new systems where both mast lights and cabling are installed from the ground up, consider installing a conductor in direct contact with the earth above the cable route. The measure aids in preventing flashovers to the cables and equalizing the potential gradient in the event of lightning striking the LED light mast or the ground.
While surge protection for LED systems carries a notable cost, the consequences of leaving them unprotected are even more burdensome to bear.
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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