SPD with MOV & GDT Technology: A Comprehensive Guide for 2025

What is an SPD with MOV and GDT Technology?

An SPD with MOV & GDT technology incorporates protective functions of both MOV and GDT components into one device. The combination of MOVs’ fast response time and the high energy capacity of GDTs makes this hybrid design withstand voltage surges even better.

What is the Function of MOV and GDT Technology?

1. MOV:

Voltage clamping MOVs are classed as a variety of resistors whose activity depends on the voltage present. With MOV, the voltage clamp breaks when the excess voltage received is too high. The MOV ensures the resistance during discharge diminishes fully to ensure no buildup of extra voltage. MOVs, unlike GDTs, do deplete frequently with continued surges. This could lead to ineffective MOVs due to surges in cascading charge voltage.

2. GDT (Gas Discharge Tube)

A GDT is recognized as a charge pulse device that possesses a gas charge within a cylinder and is termed “box” and opens under a specific degree of added voltage. Capable of sustaining energetic shock surges, surpassing the moving limiters mark, GDTs tend to have a longer afloat time than MOVs. On the other hand, they also respond way slower and are not appropriate for all applications.

3. Hybrid Integration:

Combining MOVs and GDTs in hybrid SPDs allows for the extraction of benefits from both technologies. The MOV mitigates the initial surge, while the GDT mitigates the sustained high-energy events. That is why MOVs in hybrid SPDs are robustly protected and have longer life spans.

Advantages of SPD with MOV & GDT Technology

• Protection is Greater:

They have superior protection against a wide variety of transient voltage surges.

• Life Span is Extended:

Reduces wear on MOVs due to GDTs being able to handle high-energy surges.

• Size:

Combining both technologies into a single device results in both space and simplification in its installation.

• Multipurpose:

Suitable for various applications such as residential, industrial, and telecommunications systems. IEC Supply.

Uses of MOV & GDT Technology Bundled with SPD

1. Residential Utilization:

Protects domestic appliances, electronics, and home automation devices against power surges caused by lightning or issues with the electric grid.

2. Industrial Utilization

Safeguard industrial machinery alongside control systems and PLCs from volatile Transient Voltages that can disrupt operations or damage equipment.

3. Telecommunications

Guarantees full operating capacity of communication equipment by avoiding damage from voltage spikes.

4. Northern Energy Systems

Solar inverters and wind turbines are protected from surges, which improves the longevity and efficiency of renewable energy installations.

Take into Account the Following Technical Specifications

When picking an SPD with MOV & GDT technology, pay attention to these technical parameters.

• Compliance with Standard IEC 61643-11:

Validates the international device standard for surge protection compliance on electronic products.

• Type Classification:

Type 1 (Class B)—Withstanding direct lightning strikes; Type 2 (Class C)—Surge protective devices against Transient Overvoltages; Type 3 (Class D)—Point-of-use protective measures.

• Impulse Current Rating (Iimp):

Defines the capability of the apparatus to withstand surge currents.

• Nominal Discharge Current (In):

Characterizes the nominal value of surge current that the device will withstand.

• Voltage Protection Level (Up):

Describes the minimum voltage above which the SPD will short circuit, while protection is still allowed to pass through to the protected equipment.

Selecting the Appropriate Surge Protection Device

Selecting the most efficient device for your system is critical for guaranteeing optimal sustained protection and functionality for your electrical systems. Considering the numerous options available for SPDs, particularly those designed with MOV and GDT technology, the ideal selection depends on the precise needs of your system.

1. Assess the Potential Surge Threat

Identify the existence of voltage surge possibilities in the area. High-risk regions—like those considered to be struck frequently by lightning or having unreliable utility grids—need type 1 and type 2 classified SPDs, which can withstand higher impulse current Iimp.

2. Choose the Right Type

• Type 1 SPD (Class B) – Intended for the main service panels, protects surge SPDs that are directly lightning-induced.

• Type 2 SPD (Class C) – Protects against residual surges after primary ones.

• Type 3 SPD (Class D) – Works best when used for point of use protection – in wall sockets or very close to sensitive appliances.

3. Check Standards and Ratings

Ensure compliance with the following standards: IEC 61643-11. Check if the nominal discharge current (In) and the maximum discharge current (Imax) will work with your load capacity. For better performance, also check for low leakage current and high surge current protection.

4. Application-Specific Needs

Movable and protective SPDs for industrial applications, for solar power systems, and even for data lines exist.

Installation and Maintenance Tips

Avoid installation as a one-time task and incorporate routine maintenance sessions to significantly boost the lifespan and efficiency of your SPD system.

1. Correct Placement

Locate SPDs as near as possible to the power source while installing electrical power entry into the facility. For multi-stage protection, combine Type 1, 2, and 3 SPDs throughout your distribution system. 

2. Grounding is Crucial

Double-check that the SPD is grounded correctly. Without proper grounding, the surge energy cannot be safely dissipated, increasing the chances of destruction to the downstream equipment.

3. Cross-Check Wiring and Distance

Increase routing efficiency by shortening lengths and minimizing sharp wire bends. For a lowered clamping voltage, the SPD should be connected to the power panel directly.

4. Round Surveillance

SPDs that include MOV and GDT are notorious for being robust, but over time, wear and tear occur. Look for visual indicators such as status LEDs or a thermal disconnect. Regularly DISREGARD MOV failure modes and GDT voltage breakdown changes.

5. Everything will Break Eventually

Obsolete will be the newly used term for SPDs showing signs of wear and post-surge malfunction. While overloaded or aged SPDs might, in fact, still pass voltage, they will do so powerless to truly protect. 

Conclusion

The remarkable ability of SPDs with MOV & GDT technology to shield systems from elemental voltage peaks is unparalleled. With full knowledge of their functions, benefits, and applications, decisions regarding the protection of your equipment, along with the infrastructure, become elementary. For more information, visit Telebahn.