LDSP1s9 High-Iimp Type 1+2 DC SPD for Solar PV Systems

LDSP1s9 High-Iimp Type 1+2 DC SPD for Solar PV Systems

The LDSP1s9 combines Type 1 impulse-current capability and Type 2 surge protection in one DC SPD series.

For solar PV projects, this means the product is specified not only by In and Imax under an 8/20 μs surge waveform, but also by Iimp and Itotal under a 10/350 μs impulse waveform. These ratings are especially important when the surge-protection design requires a Type 1+2 DC device rather than a Type 2-only SPD.

The series is available for Ucpv values from 600V to 1500V DC. Iimp, Itotal and Up vary with the selected voltage model, allowing the SPD to be matched more closely to the electrical and impulse-current requirements of the PV system.

Key Features

• Type 1+2 DC surge protection for photovoltaic systems

• Ucpv options from 600V to 1500V DC

• In 20kA and Imax 50kA under an 8/20 μs waveform

• Iimp up to 12.5kA under a 10/350 μs waveform

• Itotal up to 25kA

• 3+0 DC protection configuration

• High-energy MOV voltage-limiting technology

• Pluggable protective modules

• Internal thermal disconnection

• Green/red operating and fault indication

• Optional remote signalling contact

• Iscpv 10kA

• 125A–160A gPV backup fuse range stated in the technical data

• 35mm DIN-rail mounting

• IP20 thermoplastic enclosure

• Main terminal capacity from 2.5mm² to 25mm²

Technical Specifications

Model Selection by Ucpv and Iimp

The correct LDSP1s9 model should be selected by checking Ucpv, Iimp, Itotal, and Up together.

Although the listed models share the same In and Imax ratings, their 10/350 μs impulse-current capability changes with the DC voltage.

Do not assume that every LDSP1s9 version has a 12.5kA Iimp rating. The 600V and 800V models provide the highest Iimp values in the series, while the 1000V, 1200V and 1500V versions have their own model-specific ratings.

Higher Impulse-Current Capability Across the LDSP1s9 Series

The main reason to consider the LDSP1s9 is its higher Type 1 impulse-current capability within the YQNT DC Type 1+2 product range.

For example, the 600V and 800V versions provide an Iimp rating of 12.5kA and an Itotal rating of 25kA. The 1000V version provides 9kA Iimp and 18kA Itotal, while the 1200V and 1500V versions provide 6.25kA Iimp and 12.5kA Itotal.

This makes the LDSP1s9 relevant to projects where the required 10/350 μs impulse-current rating is higher than that offered by a lower-Iimp Type 1+2 DC SPD.

The final model should still be selected from the actual PV voltage, required Iimp, voltage protection level and overall surge-protection design—not from the highest kA number alone.

Iimp, In and Imax: What Buyers Should Compare

The LDSP1s9 carries several different current ratings, each describing a different test condition.

Iimp – Impulse Discharge Current

Iimp is specified with a 10/350 μs waveform and represents the Type 1 impulse-current capability of the SPD.

For the LDSP1s9 series:

• 600V DC: 12.5kA

• 800V DC: 12.5kA

• 1000V DC: 9kA

• 1200V DC: 6.25kA

• 1500V DC: 6.25kA

In – Nominal Discharge Current

In is specified using an 8/20 μs waveform. All listed LDSP1s9 models have an In rating of 20kA.

Imax – Maximum Discharge Current

Imax is also based on an 8/20 μs waveform. The listed LDSP1s9 range uses an Imax rating of 50kA.

When comparing Type 1+2 solar SPDs, Iimp, In and Imax should not be treated as interchangeable ratings.

3+0 DC Protection Configuration

All listed LDSP1s9 models use a 3+0 configuration with DC+, PE and DC− connections.

The product uses three protective modules and provides surge-current paths between the DC conductors and protective earth according to the supplied wiring arrangement.

The correct SPD configuration should be considered together with the photovoltaic system voltage, earthing arrangement and overall protection design.

Solar PV Applications

The LDSP1s9 is intended for surge protection on the DC side of photovoltaic power systems where Type 1+2 protection is specified.

Typical applications may include:

• PV combiner boxes

• Solar array DC protection

• Photovoltaic DC distribution panels

• Solar inverter DC input circuits

• Commercial rooftop PV installations

• Industrial photovoltaic systems

• High-voltage PV DC systems up to 1500V

For projects with higher lightning exposure or specified 10/350 μs impulse-current requirements, check the required Iimp against the exact voltage version before ordering.

Pluggable Modules, Status Indication & Remote Signalling

The LDSP1s9 uses pluggable MOV protection modules, making inspection and module replacement more convenient without replacing the complete base assembly.

Internal thermal disconnection is integrated into the design.

The front status indicator provides a quick local check:

• Green: normal operating condition

• Red: fault or replacement condition

An optional remote signalling contact can be used where SPD status needs to be monitored from a control cabinet or centralized monitoring system.

The technical data lists NC, COM and NO contacts with a maximum load of:

• 250V / 0.5A AC

• 30V / 3A DC

Installation and gPV Backup Protection

The LDSP1s9 is designed for 35mm DIN-rail mounting and uses screw terminals for main conductors from 2.5mm² to 25mm².

The supplied technical data specifies a maximum backup fuse range of:

125A–160A gPV

Backup protection should be coordinated with the selected SPD model and the electrical conditions of the PV installation.

When preparing the installation, verify:

• Maximum PV DC voltage

• Selected Ucpv

• Required Iimp and Up

• 3+0 connection arrangement

• PE connection

• Conductor size

• Upstream short-circuit protection

• Cable routing and connection length

Installation should be carried out by qualified electrical personnel using the confirmed product documentation and applicable project requirements.

OEM & ODM Type 1+2 DC SPD Solutions

YQNT supports OEM and ODM projects for solar equipment suppliers, electrical distributors, panel builders and private-label electrical brands.

For the LDSP1s9 series, available project discussions may include product marking, private labels, packaging, documentation, voltage-model selection and optional remote signalling.

For an accurate product recommendation, send us:

• PV system voltage

• Required Ucpv

• Required Iimp rating

• Required voltage protection level

• Remote-signal requirement

• Target-market documentation requirements

• Estimated order quantity

Our team can then help identify the appropriate LDSP1s9 model and confirm the available customization options.

FAQs

What makes the LDSP1s9 different from a standard Type 2 DC SPD?

The LDSP1s9 is a Type 1+2 DC SPD. In addition to In and Imax ratings under an 8/20 μs waveform, it has an Iimp rating under a 10/350 μs waveform.

This additional impulse-current rating is one of the key differences between the LDSP1s9 and a Type 2-only solar SPD.

How does the LDSP1s9 differ from the LDSP1s6.25?

Both series are Type 1+2 DC SPDs, but their model-specific Iimp ratings are different.

The LDSP1s9 provides higher Iimp values across the corresponding voltage options—for example, 12.5kA at 600V and 800V, and 9kA at 1000V.

This makes the LDSP1s9 the higher-impulse option when the project specification requires these ratings.

Which model should I choose for a 1000V PV system?

The LDSP1s9-DC1000 is the 1000V DC version. Its listed ratings are In 20kA, Imax 50kA, Iimp 9kA, Itotal 18kA and Up ≤3.8kV.

The actual maximum DC operating voltage of the PV system should still be confirmed before selecting Ucpv.

Which models provide 12.5kA Iimp?

The LDSP1s9-DC600 and LDSP1s9-DC800 versions are rated at Iimp 12.5kA under a 10/350 μs waveform.

Is there a 1500V DC version?

Yes. The LDSP1s9-DC1500 has Ucpv 1500V DC, Iimp 6.25kA, Itotal 12.5kA and Up ≤5.2kV.

Is remote signalling available?

Yes. Remote signalling is optional, with NC, COM and NO contacts for connection to an external monitoring circuit.

What backup fuse is specified?

The supplied technical data lists a maximum backup fuse range of 125A–160A gPV.

Related Solar DC Surge Protection Products

If a different impulse-current level or SPD classification is required, compare the LDSP1s9 with other YQNT solar DC protection products, including:

• Lower-Iimp Type 1+2 DC SPD series

• Type 2 Solar PV SPDs

• PV fuse links and PV fuse holders

• DC circuit protection products

Send us your PV voltage, SPD classification, required Iimp, and order quantity for model selection and quotation.