Solar SPD for Photovoltaic Surge Protection
A solar SPD is a surge protective device installed in photovoltaic systems to protect PV panels, combiner boxes, inverters, and AC distribution equipment from lightning-induced surges and transient overvoltage.
LEEYEE supplies DC and AC solar surge protective devices for rooftop, commercial, and utility-scale PV systems. This page helps buyers understand solar SPD types, voltage ratings, installation positions, and product selection. For complete system-level protection design, view our Solar PV Surge Protection Solution.
Quick Answer
Solar SPD means solar surge protective device. It limits transient overvoltage and diverts surge current away from sensitive PV equipment.
In a solar PV system, DC SPDs are installed between the PV array and inverter, while AC SPDs are installed after the inverter on the AC output side.
Definition
What Is a Solar SPD?
A solar SPD, also called a PV surge protective device or solar surge protector, is used to reduce the risk of equipment damage caused by lightning, switching operations, and transient overvoltage in photovoltaic power systems.
Why It Matters
Why Solar PV Systems Need Surge Protection
Solar PV systems are usually installed outdoors, with long cable routes and sensitive inverter electronics. This makes surge protection an important part of the system protection design.
Outdoor Exposure
PV modules, DC cables, and combiner boxes are exposed to outdoor lightning-related surge risks.
Long Cable Runs
Long DC cable routes can pick up induced surge voltage, especially in rooftop and ground-mounted PV systems.
Inverter Protection
Inverters contain sensitive electronics. Surge damage may cause downtime, replacement cost, and power generation loss.
System Continuity
Proper SPD selection helps reduce unexpected failure in PV strings, DC boxes, inverter cabinets, and AC panels.
Installation Position
Where Is SPD Installed in a Solar PV System?
Solar surge protection is usually arranged on both the DC side and the AC side. The DC SPD protects the PV array and inverter input. The AC SPD protects the inverter output and downstream distribution system.
DC Side vs AC Side
DC Solar SPD vs AC Solar SPD
A complete solar surge protection design usually considers both sides of the inverter. DC and AC SPDs are not interchangeable because the circuit characteristics and applicable standards are different.
DC Solar SPD
DC solar SPD is designed for photovoltaic DC circuits and is commonly used for 600V, 1000V, or 1500V DC PV systems.
- PV string combiner box
- DC distribution box
- Inverter DC input side
- Photovoltaic DC circuits
AC Solar SPD
AC solar SPD is installed after the inverter to protect AC low-voltage power circuits and distribution equipment.
- Inverter AC output
- AC distribution cabinet
- Main low-voltage panel
- Grid-connected PV systems
Selection Guide
How to Choose a Solar SPD
Choose a solar SPD according to the installation side, PV system voltage, SPD type, discharge capacity, wiring method, and project lightning exposure.
| Selection Point | What to Check | Recommended Direction | Why It Matters |
|---|---|---|---|
| Installation Side | DC side or AC side | Use DC SPD before inverter; use AC SPD after inverter | DC and AC circuits require different SPD designs |
| PV System Voltage | Maximum calculated PV string open-circuit voltage at the minimum design temperature | Select an SPD with a suitable Ucpv above the calculated maximum string voltage | Module Voc, modules per string, and low-temperature voltage rise must be considered |
| SPD Type | Lightning exposure, external lightning protection, and risk assessment | Type 2 for induced and switching surges; Type 1+2 where partial lightning current may enter the system | The required SPD class depends on the actual lightning-current exposure of the installation |
| Discharge Capacity | In, Imax, or Iimp rating | Select based on project protection design | Higher surge risk may require higher discharge capacity |
| Wiring / Poles | PV wiring structure and grounding method | 2P, 3P, 4P, or project-specific configuration | Correct pole configuration supports safe surge discharge |
| Installation Method | Cabinet, combiner box, or DIN rail mounting | 35mm DIN rail pluggable SPD is commonly used | Easy replacement and maintenance reduce downtime |
| Standard Reference | PV DC side or AC power side | IEC/EN 61643-31 for PV DC SPD; IEC/EN 61643-11 for AC SPD | Standards help define testing and performance requirements |
Do not select the DC SPD only from the nominal PV system voltage. Module Voc, modules per string, and the low-temperature voltage correction should also be considered. Final SPD selection should be confirmed according to the actual PV design, grounding system, cable length, lightning risk level, and local electrical requirements.
Product Selection or System Design
Do You Need a Solar SPD or a Complete PV Protection Solution?
Choose a solar SPD product when you already know the required installation side, system voltage, SPD type, and wiring configuration. A complete PV surge protection solution is recommended when the system architecture still needs to be evaluated.
Choose a Solar SPD Product
Use this page when the main task is to compare DC or AC SPD types, voltage ratings, discharge parameters, pole configurations, and common installation positions.
- DC or AC side is already known
- System voltage and wiring are confirmed
- Required SPD type is already defined
- A product model or quotation is needed
Choose a Complete PV Protection Solution
Use a system-level solution when you still need to determine how the DC side, AC side, cable routes, lightning protection system, and communication lines should be protected together.
- Type 2 or Type 1+2 is not yet determined
- SPD installation positions need to be planned
- Long cable routes may require protection at both ends
- RS485, Ethernet, or monitoring lines may need protection
Product Options
Solar SPD Product Types for PV Projects
LEEYEE provides solar SPD options for DC-side and AC-side protection in PV systems, helping buyers match surge protection devices with real installation requirements.
SPD
DC Solar SPD
For PV strings, combiner boxes, DC protection boxes, and inverter DC input protection.
PV SPD
Type 1+2 Solar SPD
For PV systems where partial lightning current may enter the installation, such as projects affected by an external lightning protection system or identified by risk assessment.
SPD
AC Solar SPD
For inverter AC output, AC distribution boxes, low-voltage panels, and grid-connected PV systems.
Applications
Solar SPD Applications
LEEYEE solar SPD products are suitable for different PV protection applications, from small rooftop systems to commercial and utility-scale projects.
Residential Rooftop Solar
Protects inverter input/output and rooftop PV cable routes from transient surge voltage.
Commercial PV Systems
Suitable for factory rooftops, commercial buildings, schools, hospitals, and public facilities.
Utility-Scale Solar Farms
Supports PV string, combiner box, inverter station, and AC distribution protection design.
Solar Combiner Boxes
Commonly integrated into DC combiner boxes together with fuses, isolators, and monitoring devices.
Inverter Cabinets
Used on DC input and AC output sides to reduce surge-related inverter damage risk.
OEM Electrical Panels
Available for cabinet builders, distributors, solar EPC companies, and OEM protection assemblies.
Technical Reference
Typical Solar SPD Technical Data
The following table gives common selection parameters for solar surge protective devices. Exact values should be confirmed according to the selected model and project requirement.
| Parameter | Common Solar SPD Reference | Meaning for Buyers |
|---|---|---|
| Product Type | DC SPD / AC SPD / Type 2 / Type 1+2 | Choose according to installation side and surge risk |
| Maximum Continuous Operating Voltage | 600V DC / 1000V DC / 1500V DC | Select Ucpv above the calculated maximum string voltage at minimum design temperature |
| Nominal Discharge Current | Commonly selected by In rating | Represents repeated surge discharge capability |
| Maximum Discharge Current | Commonly selected by Imax rating | Represents maximum 8/20 μs surge current capability |
| Impulse Current | Commonly used for Type 1 or Type 1+2 SPD | Important for higher lightning current protection |
| Voltage Protection Level | Up value depends on model and voltage rating | Lower Up helps reduce voltage stress on protected equipment |
| Installation | 35mm DIN rail, pluggable module design | Supports easier maintenance and replacement |
| Standards | IEC/EN 61643-31 for PV DC SPD; IEC/EN 61643-11 for AC SPD | Helps buyers compare SPD performance and application suitability |
LEEYEE / CNSPD
Solar SPD Supplier for Safer PV Electrical Systems
LEEYEE is a specialized surge protection and low-voltage protection supplier, trusted for solar PV, power distribution, telecom, industrial, and OEM applications.
CNSPD is LEEYEE’s surge protection-focused brand platform, built to help global buyers source reliable SPDs and related low-voltage protection products.
FAQ
Solar SPD FAQ
These questions help buyers understand solar SPD selection, installation position, and common protection requirements for PV systems.
What does solar SPD mean?
Solar SPD means solar surge protective device. It is installed in photovoltaic systems to limit transient overvoltage and discharge surge current before it damages PV equipment.
What is SPD in a solar system?
In a solar system, SPD is a protection device used on the DC side, AC side, or both sides of the inverter to protect solar panels, combiner boxes, inverters, and distribution panels from surge voltage.
Do solar panels need SPD?
Solar panels and PV systems are often installed outdoors with long DC cable routes, so SPD is strongly recommended, especially in areas with lightning activity or unstable grid conditions.
Where should SPD be installed in a solar PV system?
DC SPD is usually installed between the PV array and inverter, such as inside the combiner box or near the inverter DC input. AC SPD is usually installed after the inverter on the AC output side.
What is the difference between DC solar SPD and AC solar SPD?
DC solar SPD is designed for photovoltaic DC circuits such as 600V, 1000V, or 1500V DC systems. AC solar SPD is used after the inverter for AC low-voltage distribution circuits.
How do I choose a solar SPD?
Choose a solar SPD according to system voltage, DC or AC installation side, SPD type, discharge current rating, wiring configuration, grounding method, and project lightning exposure.
What voltage solar SPD should I use?
The DC SPD should be selected according to the calculated maximum PV string open-circuit voltage at the minimum design temperature. Module Voc, modules per string, and low-temperature voltage rise should be considered before selecting a suitable Ucpv.
Is Type 2 SPD enough for solar PV?
Type 2 PV SPD is commonly used where protection is mainly required against induced and switching surges. Type 1+2 PV SPD should be considered where partial lightning current may enter the electrical system, such as installations affected by an external lightning protection system or projects identified by risk assessment.
Can one SPD protect both DC and AC sides?
No. DC and AC circuits have different electrical characteristics. A PV system usually needs a DC SPD before the inverter and an AC SPD after the inverter if both sides require protection.
What is the difference between a solar SPD product page and a solar surge protection solution?
A solar SPD product page explains device types, voltage ratings, parameters, and common installation positions. A solar surge protection solution evaluates the complete PV system, including DC-side protection, AC-side protection, cable length, lightning exposure, external lightning protection, grounding, and communication interfaces.
What information should I provide for solar SPD selection?
You can provide PV system voltage, inverter type, DC or AC side installation, grounding method, number of strings, cabinet type, and project location or lightning risk level.
Related Product Topics
Related Solar SPD and Surge Protection Pages
Explore related surge protection products and solar PV protection pages to compare DC SPD, AC SPD, and complete PV protection solutions.
Need Help Selecting the Right Solar SPD?
Tell us your PV system voltage, maximum string Voc, inverter side, application, grounding method, and cabinet requirement. LEEYEE can help recommend a suitable DC or AC solar SPD.