DC SPD Surge Protective Device is a power protection device that protects electrical equipment from potential damage due to overvoltage or current spikes. Activating the protection mechanism to control the inevitable voltage spike takes less than a second. There could be several causes of the voltage spike. The most common ones are lighting strikes, power switching, short circuits, or electrical equipment or wiring malfunctioning.
Let’s get to know its types and various components in detail.
DC SPD Types
The selection of the SPDs is made keeping in view the three standard parameters of the waveform. The types of SPDs are classified according to these waveforms.
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Type 1 DC SPD
Type 1 DC SPD are pluggable SPDs, which means they can easily be plugged and replaced without disconnecting the DC SPD wiring or connection. The type 1 SPD is based upon a 10/350 waveform, which means a 10-microsecond rise time to peak current and a 350-microsecond decay time to half the value.
This SPD is most suitable for areas where there is an increased risk of higher surge current. The type 1 SPD installation is made at the main entrances, tolerates most of the power surge, and serves as the primary protection.
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Type 2 DC SPD
Type 2 DC SPD is based on an 8/20 waveform, which means it takes 8 microseconds rise time to peak current and a 20 microsecond decay time to its half value. They are also available with the perk of being pluggable and are easy to replace.
They are secondary protection devices that provide moderate protection. They are suitable to be installed at sub-distribution boards and provide complete protection against overvoltage to the equipment connected to them.
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Type 1+2 DC SPD
Type 1+2 DC SPD has the combined benefit of both the types, type 1 and type 2, of DC SPD. It works both ways; it can handle and suppress the highest voltage and also the lowest of it. It is suitable for wavefrom 10/350 and has a higher tendency to tolerate extreme voltage fluctuations.
It is practical to be installed in communication and medical equipment as it provides a higher protection rate and is suitable for both direct and indirect surges in industrial and residential setups. It exempts you from the need to install the type 1 and 2 SPDs separately.
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Type 3 DC SPD
Type 3 DC SPD is generally installed solely for the equipment and circuits that must be protected. These SPDs are used in addition to the type 2 SPDs for enhanced and foolproof protection. They are based upon a waveform of 1.2/50 voltage wave and 8/20 current wave.
They are comparatively capable of handling not-so-high energy surges. It is the reason they are being used in combination with type 1 or 2 SPDs for the voltage spike that they have already lowered.
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Photovoltaic Surge Protector
The photovoltaic protector is a DC SPD that protects against voltage fluctuations caused directly or indirectly by lighting or swapping operations. It is mainly DC SPD for solar panels and is used in photovoltaic/PV solar panel systems. They have the capacity to withstand high voltages up to 1500V DC. The PV system converts the energy from the sun directly into electricity.
An unprotected solar PV system can face severe damage from sudden lightning or electrical faults. And here comes the solar DC SPD connection for your rescue, thus expanding the lifespan of your expensive equipment.
Components of DC Surge Protective Device
Let us give you a brief overview of the main components in DC SPD manufacturing, which are more often used.
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Discharge Gap
It is also known as the protection gap. It comprises two metal rods that are at a gap. One is connected to the power supply phase or the device’s neutral line (N); the second rod and ground line (Pe) are interconnected. In case of a rise in voltage, the excess voltage is directed to the ground, providing device protection from potential damage.
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Gas Discharge Tube (GDT)
It is yet another essential component of DC SPD manufacturing. It activates only when the voltage exceeds the nominal limit. It consists of a glass or ceramic tube filled with an inert gas. It has two electrode plates at a safe distance. When there is a rise in voltage, the gas inside the tube is ionized and acts as a current conductor to let it flow through the tube, leading it toward the ground.
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Metal Oxide Varistor
It’s a main component of DC SPD manufacturing. It is responsible for absorbing and diverting away the excess voltage during a surge. The metal oxide varistor of zinc oxide is among the most used types. It has a high resistance against current during the standard voltages. During a surge, its resistance decreases, and it conducts the excess voltage, deriving it away from the connected equipment.
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Suppressor Diode
Suppressor diodes are a vital component in certain kinds of SPD, particularly low-energy consumption. They are a fast-action component in the form of a diode that suppresses and grounds excess current in the voltage spike. The two poles of the diode absorb and clamp the high voltage to a predetermined level.
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Choke Coil
It is among the common suppression devices for DC SPD manufacturing with ferrite at its core. It is often used in combination with suppressor diodes or varistors to enhance the protection against current fluctuation. It consists of two coils of the same size, which are turned around the ferrite core, making it a four-terminal device.
Important Consideration Before Selecting DC SPD
Specific points have to be considered before opting for a DC SPD connection.
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Current Rating
It refers to the capacity of the device to tolerate the current during the surge period. It may be the repeated constant high current during the period or a maximum peak rate that needs to be withstood by the device. The trick is to monitor the possible highest voltage in the area and then buy the device that protects voltage rated above that.
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Response Time
The response time is yet another perk for a device to be competent enough. It is the time that a device may take to activate the protection once the voltage surge occurs. And let us tell you that this must be spontaneous, maybe less than a nanosecond(ns), so as to provide guaranteed protection against the voltage spike.
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Surge Current Capacity
The term refers to the maximum capacity of a DC SPD to handle current during a surge. The power ratings are expressed in kiloamperes (kA). The common ones are 10kA, 20kA up to 60kA, depending on the nature of use.
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Voltage Rating
It is also one of the crucial points to consider when considering a DC surge protection device. It refers to the voltage limit an SPD can pass through during a voltage spike. It is termed clamping or protection voltage. Before purchasing, the voltage tolerance limit of the equipment in your area must be researched, or it may lead to DC SPD failure to tolerate the surge.
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Standards Compliance
Always make sure to select the international quality certified DC SPD. It not only assures you of reliability and maximum workability but is also safe to use. Out of thousands of device manufacturers, always select the one that complies with your DC SPD requirements and capacity.
Quality Assurance and Quality Control
LETOP is all about the complete and on-time protection of your equipment. Our claim is rightly justified by our thoroughly researched products with strict quality control. Our technicians make our devices after comprehensive research by researchers.
Not only that but the final devices are also tested and checked repeatedly for any DC SPD fault to ensure the promised quality. We aim to provide our customers with the most up-to-date solutions. Our DC SPDs are available in DC SPD 1000V and DC SPD 1500V.
We have proved to be one of the most reliable choices for customers, distributors, and wholesalers due to the uncompromising quality at the best possible customer-friendly price you will ever come across.
Just shoot a message and we are here to solve your electrical problems!
Final Words
We have the complete package under one roof. From the production of components to the final products and their testing and packing, we cover it all under strict quality control and professional supervision. We provide high-quality products with customization options that meet your specifications. With 20 years of experience in the field and a front-line DC SPD manufacturer in China, we continuously strive to upgrade our existing products to keep pace with innovative technology and the increasing demand of customers.
