A DC surge protector, also called a DC SPD or DC surge protection device, limits transient overvoltage on direct-current power circuits. Correct selection depends on the DC source, maximum continuous voltage, SPD type, discharge ratings, protection level, wiring and certificate scope—not one kA number alone.
For solar PV, first confirm the maximum DC voltage and select a PV-rated SPD with suitable Ucpv. Then check Tipe 2 atau Tipe 1+2, In, Imax, Iimp where required, Up, wiring configuration and exact certificate scope.
Daftar Isi
Which DC Surge Protector Should You Choose?
Start with the electrical system, not the product catalogue. This decision table gives engineers, PV combiner-box manufacturers, panel builders and technical buyers a fast first check.
| Your System | Check First | Arahan SPD | Confirm Before Approval |
|---|---|---|---|
| 600V PV system | Maximum calculated PV string voltage | Review a PV SPD with suitable Ucpv in the 600V group | Type 2 or Type 1+2, Up, wiring mode and certificate scope |
| Sistem PV 1000V | Maximum string Voc at the lowest design temperature | Review a 1000V Ucpv PV SPD when suitable for the calculated voltage | In, Imax, Iimp if required, Up, poles and installation position |
| Sistem PV 1500V | Maximum string voltage and inverter DC-input design | Review a 1500V Ucpv PV SPD for suitable high-voltage PV architecture | Lightning protection concept, SPD type, Up and exact certificate scope |
| Daya DC tegangan rendah | Maximum operating or charging voltage and source characteristics | Use an SPD explicitly suitable for the actual DC power system | Uc, Up, fault current, grounding and protection mode |
| Battery / other DC source | Maximum DC bus voltage and available fault current | Do not assume a PV SPD is automatically suitable | Applicable standard, source behavior and manufacturer approval |
DC SPD Selection in Six Decisions
Identify the DC source
PV, battery, DC distribution or another DC power source.
Confirm maximum voltage
Use the highest real voltage at the SPD terminals.
Pilih tipe SPD
Choose Type 2 or Type 1+2 from the lightning protection concept.
Compare surge ratings
Read In, Imax, Iimp and Up together.
Match the topology
Confirm DC+, DC−, PE, poles and protection modes.
Verify evidence
Match the exact model with datasheet and certificate scope.
What Is a DC Surge Protection Device?
A DC surge protective device is connected to a direct-current power circuit to limit transient overvoltage and divert surge current away from protected equipment. Under normal conditions, the SPD remains in a high-impedance state. When a transient exceeds its protective threshold, the protection elements conduct and provide a lower-impedance path for surge current.
Typical DC protection points include photovoltaic strings, combiner boxes, inverter DC inputs and DC distribution equipment. Other DC applications may also require surge protection, but the SPD must be suitable for the characteristics of the actual DC source.
Why AC and DC Surge Protectors Are Not Interchangeable
AC and DC circuits behave differently during abnormal current conditions. AC current naturally passes through zero every cycle, while a DC source does not provide the same natural zero crossing. This affects fault interruption, thermal disconnection and end-of-life behavior.
A photovoltaic circuit should therefore use a surge protective device designed and tested for PV DC service. Do not select an ordinary AC SPD merely because its printed voltage appears similar.
How to Select a DC SPD Step by Step
Identify the application before choosing a voltage
Determine whether the circuit is photovoltaic or another DC low-voltage power system. PV SPDs have a dedicated product standard, and photovoltaic source characteristics differ from batteries, rectifiers and other DC supplies.
Confirm Uc or Ucpv against the maximum DC voltage
For photovoltaic applications, Ucpv is the maximum continuous operating voltage of the PV SPD. It must remain suitable for the highest voltage that can appear at the device terminals.
Module open-circuit voltage increases as temperature falls. PV design should therefore consider the maximum string voltage at the lowest relevant temperature rather than only nominal array voltage.
Lihat DC SPD Ucpv selection guide for the detailed voltage-selection logic.
Choose Type 2 or Type 1+2 from the lightning protection concept
Type 2 PV SPDs are used for induced and switching surge protection where lightning-current duty is not required. Type 1+2 devices add lightning-current capability tested using a 10/350 μs impulse.
The decision should consider the external lightning protection system, lightning protection zones, separation distance, installation position and project specification.
Read In, Imax and Iimp as different ratings
In is the nominal discharge current associated with the defined 8/20 μs test waveform.
Imax is the maximum discharge current under the defined 8/20 μs test.
Iimp is the impulse discharge current used for Type 1 lightning-current duty with the 10/350 μs waveform.
These values should not be compared as though they represented the same test condition.
Check Up, not only the discharge-current number
Naik is the voltage protection level. It helps indicate the residual voltage presented to the protected side under the defined test condition.
Effective protection also depends on installation. Long connecting conductors can add inductive voltage during a fast surge.
Match protection modes and pole arrangement
The SPD configuration must match the electrical topology. Confirm the required paths between DC+, DC− and PE rather than selecting a device from pole count or physical appearance alone.
Check fault-current and backup-protection requirements
Review the exact manufacturer's instructions for backup fuse or protective-device coordination, prospective fault conditions, conductor sizes and tightening torque.
Verify the exact datasheet and certificate before approval
A certificate held by one voltage group or model structure does not automatically cover another model. Match the voltage, series, pole structure, standard and certificate reference before tender submission, OEM marking or purchasing approval.
DC SPD Parameters Buyers Need to Understand
| Parameter | Makna | Selection Question | Common Error |
|---|---|---|---|
| Uc / Ucpv | Tegangan operasi kontinu maksimum. | Can the SPD withstand the maximum voltage continuously present? | Choosing from nominal system voltage only. |
| In | Nominal discharge current using the defined 8/20 μs waveform. | What Type 2 nominal discharge performance is specified? | Calling In the maximum surge current. |
| Imax | Maximum discharge current using the defined 8/20 μs waveform. | What maximum Type 2 discharge rating is documented? | Selecting only from the largest kA value. |
| Iimp | Arus pelepasan impuls menggunakan bentuk gelombang 10/350 μs. | Does the project require Type 1 lightning-current capability? | Membandingkan Iimp secara langsung dengan Imax. |
| Naik | Tingkat perlindungan tegangan. | Is the protection level coordinated with the protected equipment? | Ignoring conductor-induced voltage. |
| Mode perlindungan | Electrical paths across which protection is provided. | Does the SPD match DC+, DC− and PE topology? | Selecting from pole count alone. |
| Perlindungan cadangan | Required coordination with fuse or protective device. | What does the exact product instruction specify? | Using another model's fuse value. |
| Lingkup sertifikat | Models and ratings actually covered by the document. | Is the ordered model covered by the submitted certificate? | Using one certificate for an entire product family. |
600V vs 1000V vs 1500V DC SPD
LEEYEE currently organizes photovoltaic DC SPD certification and technical-document groups around 600V, 1000V and 1500V DC. These should be treated as separate voltage and document scopes. Final selection depends on the actual PV design and exact model.
SPD DC 600V
For applicable lower-voltage photovoltaic circuits where the calculated maximum voltage is compatible with the selected Ucpv.
View 600V DC SPD options →SPD DC 1000V
A common PV voltage group for rooftop, commercial and combiner-box applications. Check string Voc, Ucpv and protection class.
View 1000V technical documents →SPD DC 1500V
Used in suitable high-voltage PV architectures. Lightning exposure, protection class and certificate scope remain important.
View 1500V DC SPD options →Verified LEEYEE PV DC SPD Evidence
Technical claims should be traceable to an exact model and document. LEEYEE separates PV DC SPD certificate coverage by voltage group and model rather than presenting one generic certificate for every product.
The information below reflects the current LEEYEE certificate-scope records. Before formal filing, verify the latest certificate copy and exact model coverage.
- Ruang lingkup: SPD DC PV
- Models: LY1-C40PV/2S, LY1-C40PV/2
- Standar: IEC 61643-31:2018
- In: 20kA
- Imax: 40kA
- Iimp: 6.25kA
- Naik: 2.2kV
- TÜV: R 50539472 0001
- CE: AN 50539473 0001
- Ruang lingkup: SPD DC PV
- Series: LY1-C40PV
- Standar: IEC 61643-31:2018
- In: 20kA
- Imax: 40kA
- Iimp: 6.25kA
- Naik: 3.6kV
- TÜV: R 50532288 0001
- CB: HU-003767
- Ruang lingkup: SPD DC PV
- Models: LY1-C40PV/3S, LY1-C40PV/3
- Standar: IEC 61643-31:2018
- In: 20kA
- Imax: 40kA
- Iimp: 6.25kA
- Naik: 5.6kV
- TÜV: R 50539515 0001
- CE: AN 50539518 0001
Technical Documents Available Before Model Approval
LEEYEE's technical-download center provides model-level information for selected 600V, 1000V and 1500V PV DC SPDs so engineers can verify the product before ordering.
Where Is a DC SPD Installed in a Solar PV System?
Typical PV protection positions include the array or combiner-box side and the inverter DC input. Larger installations may require coordinated SPDs at more than one position depending on cable routing, lightning protection zones and the overall protection concept.
Keep SPD connection conductors as short and direct as practical. A technically correct SPD can provide poorer effective protection if unnecessary conductor length or loops add inductive voltage during a fast transient.
Type 2 DC SPD vs Type 1+2 DC SPD
| Keputusan | Jenis SPD DC 2 | Jenis SPD DC 1+2 |
|---|---|---|
| Main duty | Induced surge and switching-transient protection. | Lightning-current duty plus Type 2 surge protection. |
| Test current | In / Imax based on the 8/20 μs waveform. | Includes Iimp based on the 10/350 μs waveform. |
| Typical decision factor | Locations where lightning-current duty is not specified. | Locations where the protection concept requires lightning-current capability. |
| Do not choose from | System voltage alone. | The assumption that every main panel requires Type 1. |
Browse Type 2 DC surge protective devices or the complete DC SPD product collection .
Which IEC Standard Applies to a DC SPD?
IEC 61643-31
Product requirements and test methods for SPDs intended for the DC side of photovoltaic installations up to 1500V DC.
IEC 61643-32
Selection, installation and coordination principles for SPDs connected to the DC side of photovoltaic installations.
IEC 61643-41
Requirements and tests for SPDs connected to general DC low-voltage power systems. PV SPDs remain covered separately by IEC 61643-31.
DC SPD Installation Checks That Affect Real Protection
Common DC Surge Protector Selection Mistakes
Choosing only by kA
Imax alone cannot confirm voltage, Up, SPD type or topology.
Choosing from nominal voltage
The maximum voltage at the SPD terminals is the more important design value.
Using an AC SPD on DC
A similar printed voltage does not make AC and DC SPDs interchangeable.
Ignoring Up
High discharge capability does not automatically mean low residual voltage.
Using the wrong certificate
Certificate scope must match the exact voltage group and model.
Long SPD conductors
Excess conductor length can increase the voltage seen by protected equipment.
What Should a Buyer Send Before Ordering a DC SPD?
Providing the system information first reduces the risk of model mismatch and speeds up technical confirmation.
DC Surge Protector FAQ
What is a DC surge protector?
A DC surge protector is a surge protective device designed to limit transient overvoltage on a direct-current power circuit and divert surge current away from protected equipment.
Is a DC SPD the same as a DC surge protection device?
Yes. DC SPD is the common abbreviation for DC surge protective device. DC surge protector and DC surge protection device are widely used terms for the same general product category.
Can an AC surge protector be used on DC?
Do not use an ordinary AC SPD on a DC circuit unless the exact product is explicitly rated and approved for that DC application. PV circuits should use SPDs designed for photovoltaic DC service.
How do I choose the correct DC SPD voltage?
Determine the maximum voltage that can occur continuously at the SPD terminals and select a suitable Uc or Ucpv according to the product datasheet. For PV strings, account for increased open-circuit voltage at low temperature.
Is a higher Imax always better?
No. Imax is only one rating. Correct selection also requires suitable Uc or Ucpv, SPD type, Up, In, Iimp when applicable, wiring configuration, fault conditions and certificate scope.
Should a PV system use Type 2 or Type 1+2 DC SPD?
Type 2 is generally used where induced and switching surges are the primary concern and lightning-current duty is not required. Type 1+2 is used where the lightning protection concept requires lightning-current capability.
What standard applies to solar PV DC SPDs?
IEC 61643-31 specifies requirements and test methods for SPDs used on the DC side of photovoltaic installations, while IEC 61643-32 covers selection and application principles.
Where should a DC SPD be installed in a PV system?
Common positions include the PV array or combiner-box side and the inverter DC input. Final positions depend on cable length, lightning protection zones, external lightning protection and system design.
How can I verify a LEEYEE DC SPD before ordering?
Check the exact model datasheet, wiring information, dimensions, certificate scope, product label and installation documentation before approving the product.
Need to Confirm a DC SPD for Your Project?
Send the application, maximum DC voltage, installation position, required SPD type, wiring configuration and certification requirement. For PV strings, also provide module Voc, modules per string and the lowest design temperature.
Technical note: final surge protective device selection and installation should be checked against the exact product documentation, electrical system design, applicable standard and local project requirements.
