Mersen 44020308 K2-3P440 Type 2 three-pole surge protection device for 400/690 V TN-C systems with 440 V AC maximum continuous operating voltage, 20 kA nominal discharge current and 50 kA maximum discharge current.
£112.16
The Mersen 44020308, also identified as the K2-3P440, is a robust Type 2 surge protection device (SPD) engineered to protect three-phase low-voltage electrical installations from transient overvoltages. Part of the proven Mersen Surge-Trap K2 series, it is designed for 400/690 V TN-C electrical systems and is also suitable for 400 V IT network configurations, providing dependable protection against lightning-induced surges and switching transients.
Its reinforced pluggable design enables protection cartridges to be replaced quickly without removing the complete DIN-rail base, reducing maintenance time and minimising system downtime. A clear visual status indicator allows engineers to verify the operating condition instantly, ensuring surge protection remains fully operational.
Featuring a 440 V AC maximum continuous operating voltage, 20 kA nominal discharge current and 50 kA maximum discharge current, the Mersen K2-3P440 delivers reliable secondary surge protection for industrial switchgear, commercial distribution boards, motor control centres and critical infrastructure applications.
Transient overvoltages generated by indirect lightning strikes, switching operations, motors, transformers and other inductive loads can rapidly damage PLCs, drives, communication equipment, power supplies and control electronics. Installing a dedicated Type 2 surge protection device significantly reduces the risk of equipment failure and costly downtime.
The Mersen K2-3P440 combines high surge handling capability with fast response and replaceable protection cartridges, delivering dependable long-term protection whilst simplifying preventative maintenance in demanding industrial environments.
| Voltage | 690 V |
|---|---|
| Phase | Three Phase |
| Manufacturer | Mersen |
| Series | Surge-Trap K2 |
| Model | K2-3P440 |
| SKU / Part number | 44020308 |
| Product type | Surge protection device |
| IEC SPD classification | Type 2 / Class II |
| UL SPD classification | Type 1 Component Assembly |
| Configuration | 3+0 |
| Number of poles | 3 |
| System configuration | TN-C (also suitable for 400 V IT) |
| Protection mode | L-PE(N) |
| Nominal operating voltage | 400/690 V AC |
| Maximum continuous operating voltage | 440 V AC |
| Nominal discharge current | 20 kA |
| Maximum discharge current | 50 kA |
| Voltage protection level | ≤2.0 kV |
| Response time | ≤25 ns |
| Residual current | <1 mA |
| Short-circuit withstand rating | 25 kA |
| Maximum back-up fuse | 315 A gG |
| Dynamic thermal disconnection | Yes |
| Thermal protection behaviour | Open Circuit Mode (OCM) |
| Status indication | Green (OK) / Not green (replace) |
| Remote signalling | No |
| Mounting type | DIN rail |
| DIN rail modules | 3 |
| Housing material | PA6 CT1 & PA66 CT1 |
| Terminal tightening torque | 3 Nm |
| Replacement cartridge | Cartridge ID C34 |
| Weight | approx. 0.391 kg |
| EAN | 8435297889915 |
| RoHS compliant | Yes |
| HS Code | 85363090 |
| Country of Manufacture | Spain |
The Mersen 44020308 protects three-phase 400/690 V electrical installations from transient overvoltages caused by lightning activity, switching events and inductive loads.
It is a Type 2 / Class II surge protection device designed for secondary surge protection in low-voltage electrical installations.
The K2-3P440 is designed for TN-C 400/690 V systems and is also suitable for 400 V IT network configurations.
The device provides a 20 kA nominal discharge current and a 50 kA maximum discharge current using the standard 8/20 µs surge waveform.
Yes. The pluggable construction allows the protection cartridges to be replaced without removing the complete DIN-rail base, reducing maintenance time.
Mersen Surge-Trap K2 surge protection devices are trusted by electrical engineers, panel builders and maintenance professionals to protect critical three-phase electrical systems against damaging transient overvoltages.
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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...