Whole house surge protectors reduce electrical fire risk by 60%, protect appliances, save $10,000 in potential damages, and ensure stable power.

Voltage Clamping

When it comes to surge protection for photovoltaic (PV) systems, an important principle is voltage clamping.  Voltage Clamping – The voltage clamping capability of a surge protector will ensure that the voltage remains within safe limits during transient voltage spikes.  It is important to protect sensitive components of photovoltaic systems from damage.  This feature helps do that.

To adequately clamp these voltages, a good PV surge protector may use a metal oxide varistor (MOV). The function of the MOV is to detect overvoltage conditions and quickly reduce its resistance, releasing the excess voltage from the PV system.  For example, this could result in a transient voltage spike of 1.500V being clamped by a surge protector to a safe limit (e.g. microseconds of 600V).

Energy absorption
The amount of energy a protector can absorb before failing.  This is an important feature since photovoltaic systems are often affected by such spikes.  Surge protectors used on photovoltaic systems must be able to handle high-energy events, such as lightning strikes that can deliver thousands of joules of electricity.

Common photovoltaic surge protectors have an energy absorption capacity measured in joules. In other words, a surge protector rated at or near 20,000 joules will absorb enough energy to ensure that the PV equipment connected to it is not damaged during a severe power outage.

Response time
In photovoltaic systems, the response time of the SPS is very important because it determines how quickly the device reacts to surge currents.  The faster the response time, the greater the protection for the more sensitive electronics in the PV system.  Ideally, PV applications should use surge protectors with a response time of less than 1 nanosecond.

Combining materials and technology, advanced tools such as gas discharge tubes (GDTs) with transient voltage suppression diodes or TVS enable faster response times.  Best of all, these components may respond to voltage spikes in as little as nanoseconds, instantly protecting appliances.

Cooperation with other protective devices
Surge protectors in a well-designed PV system must work in conjunction with other protective devices, such as circuit breakers and fuses, so that the entire system is protected and no one device is overburdened by a surge.

Coordination is achieved through appropriate selection and placement of surge protectors in the PV system.  For example, surge protectors can be installed at the input and output of the inverter to provide full coverage protection.  Additionally, having a similar voltage rating to other protection devices should be another modification of the surge protector for smooth operation.

Energy Absorption

Energy absorption
Energy absorption is also one of the key aspects of effective surge protection for photovoltaic systems.  Simply put, the principle is that the surge protector is expected to absorb and dissipate the extra energy generated by voltage spikes and keep it from further damaging or affecting your PV system.  High energy absorption levels are necessary to ensure the longevity and reliability of your photovoltaic system

Joule ratings and where they appear
The joule rating indicates how much energy a surge protector can handle without failing.  The higher the joule rating, the better protected your surfaces are actually going to be, especially if you live in a community that has large or severe power surges.  To put this into perspective, a 20,000 Joule surge protector can handle a fairly powerful energy event, such as a lightning strike (which can produce a surge in the tens of thousands of Joules).

In contrast, imagine a photovoltaic system in an area with more thunderstorms.  It's a simple fact of physics: During a lightning strike, the energy surge can quickly reach 10,000 joules.  A surge protector with a higher power rating will absorb all this "extra" energy, protecting critical assets (photovoltaic panels, inverters, etc.) from its effects.

Component life and material selection
The type of material can also make a significant difference in the amount of energy a surge protector absorbs.  Good surge protectors use metal oxide varistors (MOVs), gas discharge tubes, and silicon avalanche diodes, among others.  For this reason, MOVs are the best choice as they can repeatedly absorb and dissipate large amounts of energy without any noticeable degradation!

For example, a surge protector built with MOVs (varistors) rated for 800 volts can withstand large amounts of high-energy surges.  These types of MOVs can absorb thousands of joules of energy through repeated pulses and are highly recommended for use in photovoltaic systems if the system used is located in a high-risk location.  In addition, the use of high-temperature-resistant materials ensures that the surge protector always remains in action no matter how extreme the situation is.

Maximum ProDesign and configuration protection
However, achieving truly effective surge protection requires more than a large Joule rating.  In fact, getting the job done right requires smart design and proper configuration.  Surge protectors should be installed at key parts of the photovoltaic system to provide good protection.  Configure the inverter surge protector and main service board surge protector at the input and output ends of the inverter to provide multi-layer surge protection.

For example, in a commercial PV installation, you might specify a 20,000 Joule primary surge protector at the main service entrance and a secondary protector rated at 10,000 Joules at the inverter. “The layered approach also ensures that any remaining energy not absorbed by the primary protector introduced into the SHA will still be handled by the secondary protector that protects all components of the PV system.”

Regular maintenance and inspection
For optimal energy absorption, regular maintenance and monitoring of surge protectors is essential.  The bottom line here is that surge protectors don't last forever.  After a few years of surges and lightning strikes, a component within a surge protector will no longer be effective—and performance will certainly degrade over time. 2.) Routine Inspections - Having a schedule for routine inspections can help identify and replace worn parts before they become unusable.

For example, quarterly inspections might include verifying the status indicator on the surge protector and checking the clamping voltage when replacing any MOVs with obvious hot spots.  Proactive maintenance ensures that your surge protector continues to be able to absorb high-energy surges and extends the life of your PV system.

Response Time

The response time of a photovoltaic surge protector is a decisive criterion for its effectiveness.  It can be thought of as an indication of how quickly the floodgates close after opening.  The shorter the response time, the more protection your PV system has.

Why response time matters
In photovoltaic systems, modules are susceptible to voltage surges.  Because a delay of just a few nanoseconds can cause serious damage to the inverter, panels, and any other connected equipment. Transient overvoltages lasting as little as 5 nanoseconds can completely destroy delicate electronic components, unless the surge protector reacts faster than that.

Factors affecting the derivation steps
The response time of a surge protector depends on the components within it.  Uses common GDT, MOV and TVS. 5. TVS diodes have the fastest response times, sometimes in the picosecond range.  making them ideal for protecting extremely sensitive electronic components

Compare this to a MOV of a few nanoseconds - Solar flare area captured on AN/PVS-7 Cat 3 goggle display using our expensive high quality possibly triple unit compensated scope shot from the lab roof Sunset at noon.  In summary, the final decision on which component to choose depends mainly on how the PV system is set up, taking into account the sensitivity of the equipment connected at the same time.

Optimize response time
As soon as possible, don't catch fire, or worse.  Therefore, the most effective surge protectors will have very fast response times. The selection of such components itself provides fast response characteristics, and their arrangement in the explosive configuration guarantees rapid activation of the detector. The combination of TVS diode and MOV is probably balanced because the TVDS handles the spike immediately and then the MOV absorbs the rest.

Take, for example, a photovoltaic system that is equipped with both TVS diodes and MOVs at critical points. TVS diodes will react within picoseconds to clamp the initial surge, protecting the most sensitive components.  The MOV can then respond within nanoseconds, absorbing most of the surge's energy.  This multi-layered protection provides complete security.

Testing and Validation
Therefore, surge protector manufacturers conduct a series of testing procedures to ensure that their products meet the required response times.  Many of these tests focus on intentionally creating simulated overvoltage events to which the surge protector must respond.  A typical test is to subject the surge protector to a voltage spike of 1,000V and measure how long the voltage is allowed to pass.

Actual testing provides us with the most useful data on how a surge protector reacts under normal operating conditions.  According to the results of one specific study, surge protectors containing TVS diodes have a response time of less than 1 picosecond.  This proves their suitability for high-speed protection applications.

Coordination with Other Protection Devices

Without cooperation with other protection devices, photovoltaic systems cannot achieve comprehensive protection of the full spectrum.  Effective coordination – Ensures all protection devices work together to protect the entire system from surges and faults.

Circuit breakers provide important protection for photovoltaic systems as they interrupt the flow of electricity in the event of a fault.  This will require the surge protector to be paired with the overcurrent device so that they do not interfere with each other's activation.

Combination of fuse disconnectors and switches
Fuse combinations and disconnect study switches are a more important part of safety preparation for other photovoltaic systems. Surge protectors must match the ratings of these devices, otherwise they will be too sensitive and trigger them prematurely, or too slow and cause them to experience excessive stress.

Cross-layer collaborative defense
Larger photovoltaic power plants often use a multi-level protection concept.  For this purpose, multiple surge protectors may be required and installed at different levels, for example.  It consists of inverter, AC and DC array combiner box and main service panel.  Each individual protector needs to be chosen very carefully and coordinated with the other protectors.

For example, a primary surge protector on a service panel may be rated for 40kA, while separate secondary protectors on the inverter and combiner box may be rated for only 20kA.  This arrangement allows the initial protector to absorb most of the surge, and then any remaining energy falls onto the secondary protector, adding another level of protection.

Compatibility test verification
Many manufacturers perform compatibility testing to ensure that the surge protector will fully coordinate with any other protective equipment.  These tests simulate a variety of surge and fault conditions, allowing us to ensure that the protector will not only respond correctly but will not interfere with the proper operation of the circuit breaker, fuse or circuit breaker.

Environmental Resistance

Environmental resistance is another major factor to consider when designing and selecting photovoltaic surge protectors.  In order to reliably protect photovoltaic systems throughout their life cycle, these devices must be able to withstand some very harsh environmental conditions.  Environmental resistance ensures your surge protector is safe and functioning properly no matter where you install it

Weatherproofing and entry protection
"Photovoltaic surge protectors are frequently exposed to severe weather conditions such as heavy rain, snow and dust," the researchers note. To be able to withstand this, it requires a high IP (Ingress Protection) rating.  For example, products with an IP67 rating are completely dust-proof and can be submerged in 1 meter of water for only 30 minutes.

For example, imagine that a PV system is installed in a coastal area where salt spray and humidity are major factors.  Surge protectors are IP67 rated and made from corrosion-resistant materials such as stainless steel parts or UV-resistant plastic, allowing them to operate for years without degradation.

Extreme temperatures and thermal management
Surge protectors for photovoltaic systems must also be able to withstand a wide temperature range.  They need to perform in a variety of conditions, whether it's hot summers or cold winters.  Due to the above factors, surge protectors designed for photovoltaic systems usually need to operate in the temperature range of -40°C-85°C.

“For example, if this solar installation was located in a desert, daily temperatures could rise from below freezing to over 40°C. That said, surge protectors are designed with thermal management in mind—including heat sinks and temperature-resistant components , which can maximize reliable operation even under extreme changes.

Material durability and longevity
The type of materials used to manufacture surge protectors makes a significant contribution to environmental protection.  High-quality materials such as stainless steel, polycarbonate and specially treated plastics are more resistant to the environment. Why these materials are corrosion-resistant and unaffected by UV rays or physical attack.

Consider a photovoltaic system located in a mountainous area where it may be subject to strong winds and hail.  Will a surge protector built into an impact-resistant polycarbonate housing and stainless steel components still protect my system from severe weather?

This will protect you from harmful UV radiation
Surge suppressor components, especially those specifically manufactured for long-term outdoor use, can begin to corrode and be damaged by UV radiation.  Therefore, equipment must be protected using UV-resistant coatings and materials to prevent this degradation.

For example, surge protectors for rooftop photovoltaic installations should be UV protected against year-round exposure to direct sunlight.  Additionally, all of these coatings protect the inner workings from damage caused by UV rays, ensuring your protector continues to function throughout its lifetime.

Meet environmental standards
Surge protectors are designed by manufacturers to meet various environmental standards so that they can be used in various regions of the world.  If you have any further questions about these please let me know.  UL 1449 in North America and IEC 61643-11 for international markets set standards that we can use to define guidelines for resistance to environmental conditions such as humidity, temperature, and UV exposure.