LDSP1s12.5 Pluggable Type 1+2 AC SPD 275–440V

LDSP1s12.5 Pluggable Type 1+2 AC SPD 275–440V

The LDSP1s12.5 is built for projects that need both Type 1 impulse-current handling and Type 2 transient surge protection in a modular AC SPD platform.

Rather than being limited to one voltage or one wiring arrangement, the series offers four Uc ratings and several protection modes. This gives electrical panel builders, distributors and project buyers more flexibility when matching the SPD to the actual power system, conductor arrangement and surge-protection design.

The product uses MOV voltage-limiting technology with an internal thermal disconnection mechanism. Individual modules are pluggable, making inspection and replacement more practical without changing the complete SPD assembly.

Key Features

• Combined Type 1+2 AC surge protection

• Four Uc ratings: 275V, 320V, 385V and 440V AC

• Type 1 impulse-current capability with 10/350 μs waveform

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

• Iimp up to 12.5kA, depending on Uc

• Six single-phase and three-phase protection configurations

• Pluggable MOV protection modules

• Internal thermal disconnection

• Green/red operating and fault indication

• Optional remote signalling contact

• Isccr 25kA

• 35mm DIN-rail mounting

• 2.5–25mm² main terminal capacity

• IP20 thermoplastic enclosure

• Maximum backup fuse range stated as 160–200A gG

Technical Specifications

Select the Right Uc and Iimp Rating

Choosing the correct LDSP1s12.5 model starts with the maximum continuous operating voltage, Uc.

The four voltage versions do not have identical impulse-current and voltage-protection ratings, so buyers should compare Uc, Iimp and Up rather than selecting the SPD from its model name alone.

The 275V and 320V versions provide the highest Iimp rating in the series at 12.5kA. The 385V and 440V versions are listed at 9kA.

The final Uc should always be matched to the actual electrical system and protection design.

Protection Modes for Single-Phase and Three-Phase Systems

A key advantage of the LDSP1s12.5 series is the range of available protection configurations.

Rather than treating the number of modules as the only selection criterion, check the actual protection paths shown in the wiring diagram.

1+0 and 2+0 Configurations

The 1+0 configuration provides a single protection path, while the 2+0 arrangement provides protection paths for L and N toward PE according to the supplied wiring configuration.

These versions can be considered where a compact arrangement is required and the electrical system matches the specified connection method.

3+0 and 4+0 Configurations

The 3+0 and 4+0 versions are intended for multi-conductor AC systems.

The 3+0 arrangement uses phase-to-PE protection paths, while the 4+0 version adds the corresponding neutral protection path according to the product wiring diagram.

These configurations give panel builders several options when specifying a Type 1+2 SPD for three-phase distribution equipment.

1+1 and 3+1 Configurations

The 1+1 and 3+1 versions use a combination of L-to-N and N-to-PE protection paths.

This topology is different from a simple 2+0 or 4+0 arrangement, so it should be selected from the actual system configuration and earthing concept rather than only from the module count.

If the correct protection mode is unclear, provide the electrical single-line diagram when requesting a quotation.

Understanding Iimp, In and Imax

The LDSP1s12.5 carries both Type 1 and Type 2 discharge-current ratings.

Iimp – 10/350 μs Impulse Discharge Current

Iimp represents the impulse-current capability associated with the Type 1 function.

The listed ratings are:

• 275V AC: 12.5kA

• 320V AC: 12.5kA

• 385V AC: 9kA

• 440V AC: 9kA

In – 8/20 μs Nominal Discharge Current

The standard technical data lists an In rating of 20kA for the LDSP1s12.5 series.

Imax – 8/20 μs Maximum Discharge Current

The standard technical data lists an Imax rating of 50kA.

These ratings describe different test conditions. A larger numerical kA value does not automatically mean a better SPD for every installation; Type classification, waveform, Uc, Up and protection topology must be evaluated together.

Pluggable Modules and Remote Monitoring

The LDSP1s12.5 uses replaceable protection modules installed on a DIN-rail base.

This pluggable construction can make maintenance easier because an affected module can be inspected or replaced without necessarily replacing the complete SPD assembly.

Each module includes visual status indication:

• Green: normal operating condition

• Red: fault or replacement condition

Remote signalling is available as an option for installations where SPD status needs to be integrated into a control or monitoring system.

The technical data specifies NC, COM and NO remote contacts with maximum ratings of:

• 250V / 0.5A AC

• 30V / 3A DC

Typical AC Distribution Applications

The LDSP1s12.5 can be selected for low-voltage AC systems where combined Type 1+2 protection and flexible wiring configurations are required.

Typical applications may include:

• Main low-voltage distribution boards

• Incoming electrical panels

• Commercial building distribution systems

• Industrial switchboards

• Machinery and control distribution panels

• Single-phase AC distribution

• Three-phase AC distribution

• Panel-building projects requiring 1+1, 3+1 or +0 protection arrangements

The exact installation position should be determined from the overall lightning and surge protection concept.

Installation and Backup Protection

The LDSP1s12.5 is designed for installation on a standard 35mm DIN rail.

Main terminals accept 2.5–25mm² conductors according to the supplied technical data, and busbar wiring may also be used where the product configuration allows it.

The technical data lists a maximum backup fuse range of:

160–200A gG

During product selection and installation, verify:

• Nominal AC system voltage

• Required Uc

• Protection mode

• Earthing arrangement

• Required Iimp

• Up coordination

• Upstream short-circuit protection

• Conductor size

• PE connection

• Cable routing and connection length

Installation should be carried out by qualified electrical personnel using the confirmed wiring diagram and project documentation.

OEM & ODM Type 1+2 SPD Solutions

YQNT supports OEM and ODM requirements for electrical distributors, panel builders, private-label brands and project suppliers.

For the LDSP1s12.5 series, customization discussions may include:

• Uc and protection-mode selection

• Product marking and private labels

• Packaging and labels

• Remote-signalling requirements

• Product documentation

• Model combinations for specific markets

For a faster quotation, provide the system voltage, required Uc, protection mode, target market and estimated order quantity.

Frequently Asked Questions

What makes the LDSP1s12.5 different from a fixed 385V Type 1+2 SPD?

The LDSP1s12.5 is a configurable product series rather than a single fixed-voltage version.

It provides 275V, 320V, 385V and 440V Uc options together with 1+0, 2+0, 3+0, 4+0, 1+1 and 3+1 protection configurations. This gives panel builders more flexibility when matching the SPD to different AC systems.

Does every LDSP1s12.5 model have an Iimp rating of 12.5kA?

No.

The 275V and 320V versions are listed at Iimp 12.5kA, while the 385V and 440V versions are listed at 9kA.

What is the difference between 4+0 and 3+1?

The two configurations use different surge-current paths.

A 4+0 arrangement uses conductor-to-PE protection paths according to the specified wiring diagram. A 3+1 configuration combines phase-to-neutral and neutral-to-PE protection paths.

The correct topology depends on the electrical system and earthing arrangement.

Can the same series be used for single-phase and three-phase applications?

The LDSP1s12.5 range includes several protection configurations intended to support different conductor arrangements. The required configuration must still be selected from the actual system wiring.

Is the LDSP1s12.5 pluggable?

Yes. The series uses pluggable protection modules installed on a DIN-rail base.

Is remote signalling available?

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

What backup fuse is specified?

The supplied technical data lists a maximum backup fuse range of 160–200A gG.

Which Uc versions are available?

The series includes 275V, 320V, 385V and 440V AC versions.

Related AC Surge Protection Products

Need a different AC surge-protection level?

Compare the LDSP1s12.5 with other YQNT products including:

• Type 1 AC SPDs for higher lightning-current discharge

• Lower-Iimp Type 1+2 AC SPD options

• Type 2 AC SPDs for downstream surge protection

• Type 2+3 SPDs for protection closer to sensitive equipment

Send us your system voltage, protection mode, required SPD classification, and project quantity for model selection and quotation.