Mitigating LED luminaire failures due to electrical surges

As LED lighting becomes more widespread in offices, hospitals, schools, and industrial buildings, the risk of luminaire failures due to electrical surges is increasing. Understanding the causes and prevention of these surges is essential for those involved in LED installation and maintenance. In this blog post, we'll explore what electrical surges are, their impact on LED lighting, and how to prevent failures.

Reading time: 4'00"

What is an electrical surge?

An electrical surge, also known as a transient voltage or spike, is a sudden and temporary increase in the voltage of an electrical circuit. These short peaks can occur in the mains voltage from neutral, phase, and/or protective earth, often exceeding the standard operating voltage of electrical devices.

Common sources of electrical surges

1. Switching heavy machinery: In industrial environments, turning heavy machinery on or off can generate significant electrical surges.
2. Frequency drives: Devices like elevators and ventilation systems use frequency drives to adjust the speed of AC motors, which can introduce surges into the electrical system.
3. Circuit interaction: Surges can spread to other circuits via distribution boards or through closely running cables in conduits.
4. Rapidly switching loads: Frequent on-off switching of loads.
5. External sources: Surges can travel through the electrical grid from external sources, impacting buildings not directly connected to the surge source.
6. Lightning strikes: In extreme cases, lightning strikes can cause massive surges, leading to widespread electrical device failures.

Why are electrical surges harmful?

• High voltage peaks: Surges often involve voltage peaks significantly higher than the normal 230VAC mains supply voltage.
• LED driver sensitivity: LED luminaires rely on LED driver electronics to convert AC voltage to a stable low current. These drivers can tolerate limited voltage peaks, but excessive surges can travel through the electronics and cause irreversible damage.
• Fluorescent lighting vs. LED: Older fluorescent lighting systems were less sensitive to surges due to their basic electronics and higher default operational voltages.

Effects of excessive surges

• Localized damage: Generally, not all devices in a circuit fail simultaneously from a surge. More common are sporadic failures over time due to cumulative damage from smaller surges.
• Absorption of surges: All devices and cabling in a circuit absorb parts of the surge, spreading the impact and potentially causing gradual damage over time.
• Misconceptions: While extreme events like lightning strikes can cause mass failures, most surges lead to isolated luminaire failures.

What are the best strategies for protecting against electrical surges?

Choosing the right LED luminaire

LED luminaires are available with different surge immunity levels. For indoor applications, luminaires with 1-2 kilovolt (kV) surge immunity are typically sufficient, whereas industrial and outdoor lighting applications should use luminaires with 2-4 kV immunity.

Tackling surges at the source

1. Identify and suppress: The best approach to managing surges is to locate and suppress the surge at its source. This may require expert analysis and intervention.
2. Improved cable routing: Proper cable routing can prevent surges from spreading between circuits.

Additional protection measures

1. Utility operator involvement: Engaging with your utility operator can provide insights in the source or surges and ensure compliance with norms regarding electrical supply cleanliness.
2. Surge protection devices (SPDs): Installing SPDs in the electrical system can dampen surges. These devices come in various types and specifications, requiring expert advice for optimal selection and placement.
3. Integrated surge protection: Some industrial luminaires can be equipped with additional internal surge protection devices, which can be more manageable than external circuit protection. 

What should be considered when evaluating surge protection devices?

• Finite lifespan: Many SPDs can only handle a limited number of surges before needing replacement.
• Partial protection: Depending on the surge source and severity, SPDs might not be able to protect the entire circuit length.
• Data monitoring: Smart SPDs provide valuable data for identifying surge patterns and sources.

 
Electrical surges pose a significant threat to the longevity and reliability of LED luminaires in various environments. These surges can seriously shorten the lifespan of LED lights in many settings. To keep your LED luminaires running smoothly, it’s important to understand where surges come from and how they affect your lighting.

By choosing the right luminaires and implementing effective protection measures, you can greatly minimize the risk of LED failures. Working with experts and using the latest surge protection technologies are key steps to ensuring your LED lighting stays strong and lasts for years to come.