Mersen 44020412 K2-4P320 Type 2 surge protection device for 277/480 V AC TNS systems with a 4+0 configuration, 20 kA nominal discharge current and 50 kA maximum discharge current.
£146.46
The Mersen 44020412, also known as the K2-4P320, is a high-performance Type 2 surge protection device (SPD) engineered to protect low-voltage electrical installations from transient overvoltages caused by indirect lightning strikes and electrical switching events. As part of the Mersen Surge-Trap® K2 Series, this pluggable four-pole SPD is specifically designed for 277/480 V AC TNS electrical systems.
Featuring a 4+0 protection configuration, the K2-4P320 provides dedicated protection for each live conductor, making it an excellent choice for industrial switchboards, motor control centres, automation systems and commercial electrical distribution panels. With a 20 kA nominal discharge current and a 50 kA maximum discharge current, it delivers reliable protection for sensitive electrical and electronic equipment.
Its reinforced pluggable design enables fast replacement of protection cartridges while maintaining the DIN rail base in position. An integrated visual status indicator allows maintenance personnel to quickly verify the condition of the device, helping reduce downtime and ensuring continuous surge protection.
Electrical installations are exposed to damaging transient overvoltages generated by lightning activity, switching operations and utility disturbances. The Mersen K2-4P320 safely diverts surge energy away from connected equipment, helping reduce costly downtime and extending the operational life of valuable electrical assets.
Its dedicated 4+0 architecture provides individual protection for each conductor within TNS systems, making it ideal for industrial control panels, commercial switchboards, manufacturing facilities and critical electrical infrastructure requiring dependable surge protection.
| Voltage | 480 V |
|---|---|
| Phase | Three Phase |
| Manufacturer | Mersen |
| Series | Surge-Trap® K2 Series |
| Model | K2-4P320 |
| Manufacturer part number | 44020412 |
| EAN | 8435297889960 |
| Product type | Type 2 surge protection device |
| IEC SPD classification | Class II |
| EN SPD classification | Type 2 |
| UL SPD classification | Type 1 Component Assembly |
| Internal configuration | 4+0 |
| Nominal operating voltage | 277/480 V AC |
| Nominal frequency | 50 / 60 Hz |
| Maximum continuous operating voltage (Uc) | 320 V AC |
| Nominal discharge current (In) | 20 kA |
| Maximum discharge current (Imax) | 50 kA |
| Voltage protection level (Up) | ≤1.5 kV |
| Typical surge current | 5 kA over 200 impulses |
| Response time | ≤25 ns |
| Residual current | <1 mA |
| Protection modes | L-PE / N-PE |
| Network configuration | TNS |
| Number of poles | 4 |
| DIN rail modules | 4 |
| Maximum back-up fuse | 315 A gG |
| Short-circuit withstand | 25 kA |
| Thermal disconnection | Dynamic |
| Thermal protection behaviour | Open Circuit Mode (OCM) |
| Protection rating | IP20 |
| Mounting type | DIN rail |
| Operating temperature | -40 to +85 °C |
| Maximum installation altitude | 4,000 m |
| Housing material | PA6 CT1 & PA66 CT1 |
| Flammability rating | UL94 V-0 |
| Dimensions (H × W × D) | 90 × 72 × 74.4 mm |
| Weight | approx. 0.448 kg |
| RoHS compliant | Yes |
| HS Code | 85363090 |
| Country of Manufacture | Spain |
The Mersen 44020412 is a Type 2 surge protection device designed to protect 277/480 V TNS electrical installations against transient overvoltages caused by lightning activity and switching events.
The K2-4P320 is specifically designed for 277/480 V AC TNS systems using a four-pole 4+0 protection configuration.
The device has a nominal discharge current of 20 kA and a maximum discharge current of 50 kA.
Yes. The device features pluggable protection cartridges that allow individual modules to be replaced without removing the complete DIN rail base.
The device is commonly installed in industrial distribution boards, commercial switchboards, motor control centres and automation panels operating on 277/480 V AC TNS electrical systems.
Mersen Surge-Trap® K2 Series surge protection devices are trusted worldwide to improve electrical system reliability while protecting valuable industrial, commercial and infrastructure equipment 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...