SPD for DC power supply are the devices specified for DC power systems to protect electric equipment from voltage spikes or fluctuations. The device detects the voltage surge within less than a second, uses its specific components for voltage clamping, and diverts the excess energy after absorbing it.
They come in different types as per variable requirements. The most common are SPD type 1, SPD type 2, and SPD type 1+2. In today’s blog, we will summarize them so as to make the selection easy for you.
DC Surge Protective Device
What Are Type 1 And Type 2 Surge Protective Devices?
As mentioned above, they are the main SPD types used for on-time detection, absorption, and diversion of excess voltage resulting from lighting or other internal disturbances.
They work on different grounds with variable techniques and play their designated role in securing the electrical system. Type 1 Surge Protection Device leads the protection system and is the foremost barrier in the way of voltage spikes due to direct lightning. The type 2 Surge Protection Device acts as a helper to the type 1 in managing the residual voltage fluctuations that have escaped from the type 1 protection system.
1000v Type 1+2 SPD
And if you want a single solution with type 1 & 2 surge protection characteristics, type 1+2 is your go-to option. Possessing the characteristics of both type 1 and type 2, this type of SPD protects against direct and indirect voltage surges, being a more budget-friendly and convenient option.
1500v Type 1+2 SPD
Differences Between SPD Type 1,Type 2, And Type 1+2
Although the primary purpose of all the types of SPD protection remains the same, their working areas and purposes may differ according to their manufacturing techniques. The types of DC SPDs can easily be differentiated based on their purpose, capacity, technology, application, and level of protection. Let us have a brief overview of the points of difference among them and help you about how to choose DC SPD.
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Design and Construction
The types of SPD are designed with the requirements of the electrical system and the place of installation in view. They are designed with high-quality flame-retardant plastic to withstand high voltage. The material makes them compatible enough to be functional in harsh outdoor environments and high-intensity surges. Moreover, a well-designed premium quality SPD is also equipped with a disconnector in case it fails to work, so as to prevent severe damage.
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Purpose Of Installation
The Type 1 SPD acts as a first line of defense. They are installed to handle a high range of surges. In contrast, type 2 SPDs are installed to handle comparatively lower surges that either occur due to any internal fault or are already weakened by type 1 SPD. The purpose of installing type 1+2 SPD is to attain both benefits in one unit and remove the need for separate installation of type 1 and type 2 SPDs.
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Variation In Technology
The technology used in Type 1 SPDs to control and divert the surge is the spark gap or the discharge gap. The two rods in it ionize the gap between them, thus creating a conduction circuit to divert the excess current. The Type 2 SPD uses a Metal Oxide Varistor (MOV) to control transient overvoltage. In case of a surge, the resistance of the Varistor is decreased, conducting the excess voltage away from the equipment. And in the case of type 1+2 SPD, both technologies are used to tackle the high and low spikes.
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Area Of Application
Where should the DC SPD be connected? The area of operation is different for each type. The Type 1 SPD is generally installed at the main entrance or outdoor panel. It is preferred for areas having lightning strikes that are too frequent. Type 2 SPD is suitable for installation at the indoor distribution panels or before expensive electrical equipment to maximize protection. Meanwhile, the type1+2 SPD type provides dual protection of both types in one device and can be installed at the primary or distribution panels.
Area of Application for SPDs
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Level Of Protection
Type 1 SPDs provide the highest level of protection. They have the capability to tolerate high-voltage surges originating from direct lightning. On the other hand, type 2 SPDs have a lower surge tolerance capacity to withstand the surges resulting from internal causes or indirect lighting. Type 1+2 SPD provides more comprehensive and complete protection against direct and indirect lightning.
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Difference In Waveform
The type 1 SPD is based upon a 10/350 waveform. It takes 10 microseconds to reach its peak current and an extended 350 microseconds to half the value. The Type 2 SPDs have a waveform of 8/20, taking 8 microseconds to peak current and 20 microseconds to half it. The type 1 +2 SPD is manufactured with a capacity to handle both waveforms.
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Handling Capacity
The types of SPD devices have different handling capacities as per their specifications to handle various scenarios and surges. The type 1 SPD, with its waveform capacity (10/350), is designed to handle high energy surges and direct lighting that can damage electrical equipment and circuits. While type 2 SPD can handle moderate surges and overvoltage that can still cause damage to equipment and are more common. The type 1+2 SPD is a complete protection plan for direct lightning or overvoltage spikes.
To make things more concise and accessible, here is a table showing the differences between the SPD types.
| Characteristics | TYPE 1 Surge protector | TYPE 2 Surge protector | TYPE 1+2 Surge Protector |
| Level of protection | High protection | Moderate protection | Dual protection |
| Technology used | Spark gap | Metal Oxide Varistor | Both technologies combined |
| Waveform variation | 10/350 | 8/20 | Both waveforms |
| Location | Main panel | sub-distribution | Main panel |
| Primary purpose | Lighting surges | Switching or voltage surges | Both purposes |
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Lifespan
The average lifespan of the SPD types depends upon their nature of use. As a type 1 SPD surge protection device is installed for high-intensity surges, its average life span is 5-10 years, while the type 2 SPD may last somewhere between 8-12 years. The type 1+2 SPD protector’s average lifespan is 5-8 years as it experiences high and moderate surges. Sometimes, the SPDs may last you 3-5 years if they are more and more frequently prone to voltage spikes.
Which Is Better, Type 1 Or Type 2?
Although DC SPD type 1 is designed to handle high-intensity surges it can not claim to protect the entire system solely by itself. They are the main source of surge protection, managing the significant spikes from direct lightning. However, the residual part of the surge still needs the functionality of DC SPD type 2 for double protection and reassurance.
Neither type 1 nor type 2 can be regarded as better than others, as each type has its own purpose and area of operation. Your most expensive or sensitive equipment may need you to install type 2 SPD even when type 1 SPD is working already. You cannot be entirely sure of your equipment being secured enough using either type. In fact, both the types installed or, to be more comprehensive, the combined type 1+2 must be used to guarantee the maximum surge protection.
What is Type1, Type2 & Type 3 SPD?
Wrap Up
To cut it short, the biggest threat to the smooth operations of your electrical system is the voltage spike, be it due to the direct lighting or the fluctuation in current. The key to the safe and smooth operation of your electrical equipment is the installation of SPDs.
We are a genuine DC SPD manufacturer in China with over 20 years of experience in the field and export to 48 countries. With compliance with the international standards IEC 61643-31:2018 and EN 61643-31:2019, our SPDs can manage high-energy surges and fluctuations with the assurance of reliability and safety.
