Solar PV Surge Protection
Type 2 DC SPDs that protect inverters, PV modules and combiner boxes against induced lightning and switching overvoltage. Factory-direct from Soltree, with CE, TÜV and CB certification and OEM from 100 pieces.
Type 2 / Class II
For induced lightning and switching surges
In 20kA / Imax 40kA
8/20μs discharge ratings
600V 2P / 1000V 3P
Two core PV configurations
Pluggable design
35mm DIN rail mounting
CE · TÜV · CB certified · MOQ 100 pcs · 7-day lead time · Custom color, logo and packaging
How it works
A DC surge protector (SPD) sits between the PV conductors and earth. Under normal operation it stays at high impedance and has no effect on the system. When a surge appears on the DC line, it responds within 25 nanoseconds, diverts the surge current to earth and limits the voltage that reaches the inverter. Once the surge has passed, it returns to high impedance automatically.
High impedance. No leakage, no effect on power generation.
Conducts within ≤25ns and diverts surge current to earth.
Returns to high impedance and stays ready for the next event.
Product range
Choose between two STD-40-PV Type 2 models: 600V 2P and 1000V 3P. Each has a dedicated product page with electrical specifications, installation information and wiring diagrams to help you review the right configuration for your project.
Type 2 / 600V DC / 2P
A 2-pole Type 2 DC SPD for 600V PV circuits, installed in a string combiner box or near the inverter DC input. Review its specifications, 2P drawings and combiner-box installation example on the product page.
Type 2 / 1000V DC / 3P
A 3-pole Type 2 DC SPD for 1000V PV circuits, for use at the string combiner box or inverter DC side. Review the electrical ratings and wiring diagram against your PV circuit and earthing arrangement before ordering.
Selection
Compare pole counts, PV voltage ratings (Ucpv), protection levels (Up) and discharge current ratings for the 600V 2P and 1000V 3P STD-40-PV models. Use this table to shortlist a configuration, then follow the three-step guide below to review your selection.
| Model | Poles | Ucpv (V DC) | Up (kV) | In (kA, 8/20μs) | Imax (kA, 8/20μs) |
|---|---|---|---|---|---|
| STD-40-PV 600V | 2P | 600 | 2.8 | 20 | 40 |
| STD-40-PV 1000V | 3P | 1000 | 3.8 | 20 | 40 |
STEP 1
Ucpv must be equal to or higher than the highest open-circuit voltage the string can reach. Voc rises as temperature falls, so calculate it at the lowest expected site temperature, not at 25°C.
Compare the calculated maximum string voltage with the selected model: 600V DC for the 2P version or 1000V DC for the 3P version. If the maximum exceeds 1000V, neither model on this page is suitable. Use the module temperature coefficient and site design data for the calculation.
Never choose an SPD whose Ucpv is below the maximum string voltage. It will conduct during normal operation, overheat and fail.
STEP 2
Both models on this page are Type 2 / Class II SPDs for induced lightning and switching surges, with 8/20μs discharge ratings. Confirm that your project requires Type 2 protection before choosing between the 600V 2P and 1000V 3P models.
If the site design requires Type 1, combined Type 1+2 or Type 3 protection, have your designer specify the appropriate device and coordination. These two models are Type 2 only.
STEP 3
Build quality
Two SPDs with the same datasheet can perform very differently after a few seasons outdoors. The difference is in the materials. Soltree lets you specify each one.
| Component | Our premium option | Low-cost alternative on the market | Why it matters |
|---|---|---|---|
| Varistor chip | 34S square MOV (34×34mm), epoxy encapsulated | Smaller round discs, bare chips | Larger chips carry more surge energy; encapsulation resists moisture and flashover |
| Contact pins | Brass (pluggable type) | Iron | Better conductivity, spring force and corrosion resistance |
| Internal conductor | Pure copper | Brass or iron | Lower resistance, less heat during surge discharge |
| Base terminals | Copper | Iron | Stable clamping and lower contact resistance over time |
| Housing | Flame-retardant PC, UL94 V-0 | V-1 / V-2 grade plastics | V-0 is the highest flammability rating in its class |
All materials above are available as options. Tell us your target market and price level, and we will recommend a configuration.
Testing & certification
Requirements: no carbonisation, no fire, no accessible live parts after testing
Applications
Every PV project has a different layout, from a compact rooftop system to a field of string combiner boxes. Find your application below and the project details to share for selection support. Voltage rating and pole configuration depend on the actual PV circuit and wiring diagram.
For the PV DC side of home solar installations, with protection planned at the combiner box or near the inverter input. Allow access for inspection and replacement, even in compact enclosures.
For factories, warehouses and commercial roofs with multiple PV strings. Plan around the combiner and inverter locations, with a layout that supports routine inspection and scheduled maintenance.
For field arrays using string combiner boxes or distributed inverters. Review protection locations alongside the DC cable routes and the site earthing and lightning protection design.
For the solar-input side of hybrid inverter systems. Review the independent MPPT circuits against the inverter wiring diagram; battery-side protection requires a separate compatibility assessment.
For compact PV distribution boxes in mobile and standalone solar systems. Review the actual array voltage and available mounting space, rather than choosing by installation size alone.
Our PV combiner boxes ship with DC SPDs and breakers pre-installed. Share your string layout, inverter model and enclosure requirements to discuss a ready-wired configuration for your project.
Browse PV combiner boxesHave a qualified installer confirm the final arrangement against the selected model's instructions and applicable local requirements.
Keep SPD connections short and direct. Check routing and permitted lead lengths against the installation instructions.
Use the conductor sizes and tightening torques specified for the selected model.
Confirm whether backup protection is required and use the DC-rated device specified in the product documentation.
Keep the status window visible and leave service access. Follow the model instructions when the indicator calls for replacement.
For distributors & system builders
Build a DC SPD range around your brand, from housing color and product labels to retail packaging. Share your target specification, market and quantity so the product configuration and brand presentation can be discussed together.
Discuss housing color, on-product branding and packaging together for a coordinated presentation under your own label.
Final lead time depends on the agreed configuration, artwork and quantity and is confirmed with your quotation.
Match the housing to your brand or product family. Share a color reference and the models you want to include.
Add your brand to the housing and labels. Provide your logo artwork, model naming and required label information for review.
Discuss custom packaging for your sales channel. Share the box artwork, pack quantity and any carton marking requirements.
Discuss voltage rating, pole configuration, structure and material options around your application and budget. Confirm the electrical specification before the order.
01
Send the target model or application, quantity, destination market and branding requirements. Include a wiring diagram if the configuration needs review.
02
Review the proposed electrical configuration, color, label content and packaging details together with the quotation.
03
Confirm the agreed specification, artwork, quantities and lead time before the order proceeds. Keep the approved details as the reference for future orders.
Have a specification or packaging brief ready? Include it with your enquiry so we can discuss the details with your pricing request.
Request OEM PricingBefore you specify
Find answers on PV surge protection, configuration and maintenance, plus the details to prepare for an OEM order or project quotation.
A PV surge protection plan should consider the DC side as well as the AC side. Whether protection is required and which type to use depend on local installation rules, site exposure and the lightning protection design. Have your installer confirm the requirements for your project.
Use an SPD specifically rated for the circuit. PV DC and AC devices differ in their voltage ratings, internal arrangements and test requirements. An AC mains SPD is not a substitute for a PV-rated DC SPD.
Choose a Ucpv equal to or higher than the maximum PV string open-circuit voltage. Calculate that voltage at the lowest expected site temperature: if it stays within 1000V, a 1000V-rated SPD can fit; if it exceeds 1000V, neither of the two models on this page is suitable. The protection level Up and circuit arrangement must also suit the equipment. Do not select a voltage class from the inverter nameplate alone. Share the string calculation and inverter data for selection support.
Most rooftop and ground-mount PV systems without an external lightning protection system use Type 2 SPDs, which address induced and switching surges. Where lightning currents can enter the installation, Type 1 or combined Type 1+2 protection may be needed. The external lightning protection system and its separation distance affect this decision. Both STD-40-PV models shown on this page are Type 2; have your designer confirm the protection concept.
Common locations include PV combiner boxes and the DC side near the inverter. Cable lengths, routing and the lightning protection design determine whether additional protection points are needed. Have your installer confirm the locations and connection layout using the selected device instructions.
Pole count alone does not define the protection circuit. Compare the wiring diagrams, protected modes and earthing arrangement. A 3P label does not by itself confirm a Y circuit or suitability for a particular system. Send your inverter model and DC wiring diagram so the configuration can be reviewed.
Not automatically after every event. Check the status indicator and have the device and its connections inspected after a significant surge. Replace a failed unit as instructed by the manufacturer. For a pluggable model, confirm the replacement module matches the base and that the base remains serviceable.
Yes. Housing color, logo, labeling and packaging can be customized, with MOQ starting at 100 pieces per model. Share your artwork, target configuration and quantity. Confirm the final specification and delivery schedule with your quotation.
Send the inverter model, string layout, maximum string voltage if known, quantity and destination market. Include your wiring diagram, required documentation and any color, logo or packaging requirements. If the configuration is still open, tell us which details need review.
Yes. Our PV combiner box range includes configurations with DC SPDs and breakers pre-installed. Share the string count, inverter model and enclosure requirements so the available configuration can be checked against your project.
Send your inverter model, wiring diagram and quantity with your enquiry.
Get a quote
Send us your system voltage, pole count and quantity. Our engineers will recommend a configuration and reply with pricing.
Product selection & quotations
Tell us your product requirements. Our team will help you find the right solution.
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