Mersen 44020304 K2-3P320 Type 2 three-pole surge protection device for 277/480 V TN-C and TN-C-S systems, featuring a 320 V AC maximum continuous operating voltage, 20 kA nominal discharge current and 50 kA maximum discharge current.
£112.16
The Mersen 44020304, also identified as the K2-3P320, is a high-performance Type 2 surge protection device (SPD) designed to protect three-phase low-voltage electrical installations against transient overvoltages. Part of the trusted Mersen Surge-Trap K2 series, it is suitable for 277/480 V TN-C and TN-C-S systems, helping safeguard electrical equipment from lightning-induced surges and switching transients.
Its pluggable three-pole construction allows individual protection cartridges to be inspected or replaced without removing the complete DIN-rail base. A clear visual status indicator provides quick confirmation of the operating condition, helping maintenance teams identify when a cartridge requires replacement.
Featuring a 320 V AC maximum continuous operating voltage, a 20 kA nominal discharge current and a 50 kA maximum discharge current, the Mersen 44020304 provides dependable secondary surge protection for industrial switchgear, commercial distribution boards, motor control centres and automation panels.
Transient overvoltages can be introduced by indirect lightning strikes, utility switching operations, contactors, motors, transformers and other inductive loads. Although these events usually last only a fraction of a second, they can damage PLCs, variable speed drives, power supplies, communication equipment and other sensitive electrical components.
The Mersen K2-3P320 diverts excessive surge energy away from connected equipment and towards earth. Its high discharge capacity, fast-response protection technology and replaceable cartridges help improve system reliability while simplifying ongoing maintenance.
| Voltage | 480 V |
|---|---|
| Phase | Three Phase |
| Manufacturer | Mersen |
| Series | Surge-Trap K2 |
| Model | K2-3P320 |
| SKU / Part number | 44020304 |
| Product type | Surge protection device |
| IEC SPD classification | Type 2 / Class II |
| Configuration | 3+0 |
| Number of poles | 3 |
| Compatible network configurations | TN-C and TN-C-S |
| Protection mode | L-PE(N) |
| Nominal line-to-earth voltage | 277 V AC |
| Nominal system voltage | 480 V AC |
| Maximum continuous operating voltage | 320 V AC |
| Nominal discharge current | 20 kA |
| Maximum discharge current | 50 kA |
| Surge current waveform | 8/20 µs |
| Short-circuit current rating | 25 kA |
| Status indication | Visual |
| Remote signalling | No |
| Construction | Pluggable |
| Mounting type | DIN rail |
| DIN rail modules | 3 |
| Dimensions (H × W × D) | 90 × 54 × 74.4 mm |
| Weight | approx. 0.342 kg |
| EAN | 8435297889892 |
| HS Code | 85363090 |
| Country of Manufacture | Spain |
The Mersen 44020304 protects three-phase low-voltage electrical installations and connected equipment against transient overvoltages caused by lightning activity, switching operations and inductive loads.
It is a Type 2 / Class II surge protection device intended primarily as a second level of protection within low-voltage distribution systems.
The K2-3P320 is designed for three-phase 277/480 V TN-C and TN-C-S systems with a maximum continuous operating voltage of 320 V AC per protection pole.
It has a 20 kA nominal discharge current and a 50 kA maximum discharge current, based on the standard 8/20 µs surge waveform.
No. This version provides local visual status indication. The corresponding K2-3P320-M model is available for applications requiring an integrated remote signalling contact.
Yes. Its pluggable construction allows the protection cartridges to be replaced without removing the complete DIN-rail base.
Mersen Surge-Trap K2 surge protection devices are trusted by electrical engineers, panel builders and maintenance professionals to protect critical three-phase electrical installations 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...