Mersen STPT12-12K275V-4P Type 1+2 surge protection device with 12.5 kA lightning impulse current rating for 230/400 V AC three-phase plus neutral systems.
£326.99
The Mersen 83120144 STPT12-12K275V-4P is a high-performance Type 1+2 Surge Protection Device (SPD) developed to protect low-voltage electrical installations from lightning currents and transient overvoltages. Designed for industrial, commercial and infrastructure applications, it safeguards critical electrical equipment and power distribution systems against damaging surge events.
Part of the proven Mersen Surge-Trap® STPT12 Series, this pluggable DIN rail mounted surge protection device combines lightning current protection with transient overvoltage suppression in a compact modular design. It is suitable as the first level of protection in main distribution boards where external lightning protection systems are installed.
Designed for 230/400 V AC three-phase plus neutral (3Ph+N) electrical systems in a 4+0 TNS configuration, the STPT12-12K275V-4P delivers a 12.5 kA Iimp (10/350 μs) lightning impulse current rating per pole, providing dependable protection for modern electrical installations.
Surge protection devices reduce the risk of equipment damage caused by lightning strikes and electrical switching events. Installing a Type 1+2 SPD at the incoming distribution board helps maintain system reliability, minimise downtime and extend the service life of valuable electrical equipment.
The Mersen STPT12 series is widely used in industrial, commercial and infrastructure installations where dependable surge protection is required to maintain operational continuity and protect sensitive electrical systems.
| Voltage | 400 V |
|---|---|
| Phase | Three Phase |
| Manufacturer | Mersen |
| Series | Surge-Trap® STPT12 |
| Model | STPT12-12K275V-4P |
| Part number | 83120144 |
| Product type | Type 1+2 Surge Protection Device |
| IEC classification | Class I+II |
| Nominal operating voltage (Un) | 230/400 V AC |
| Maximum continuous operating voltage (Uc) | 275 V AC |
| System configuration | 3Ph+N, 4+0 TNS |
| Lightning impulse current (Iimp) | 12.5 kA (10/350 μs) |
| Maximum discharge current (Imax) | 50 kA (8/20 μs) |
| Nominal discharge current (In) | 20 kA (8/20 μs) |
| Number of poles | 4 |
| Mounting type | DIN rail |
| Format | Pluggable |
| Protection rating | IP20 |
| RoHS compliant | Yes |
| HS Code | 85363090 |
| Country of Manufacture | Spain |
It protects low-voltage electrical installations against lightning currents and transient overvoltages.
It is normally installed at the incoming distribution board as the primary stage of surge protection.
The device is designed for 230/400 V AC three-phase plus neutral (3Ph+N) TNS electrical systems.
This product combines both functions and is classified as a Type 1+2 (Class I+II) surge protection device.
The unit is designed for quick installation onto a standard DIN rail within electrical distribution panels.
Mersen Surge-Trap® surge protection devices are trusted worldwide by electrical engineers, panel builders and industrial facilities to provide dependable protection against lightning and transient overvoltages while helping maximise system uptime.
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2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...