Mersen 44020421 K2-4P440-M four-pole Type 2 surge protection device for 400/690 V AC TNS systems, featuring a 440 V AC maximum continuous operating voltage, 20 kA nominal discharge current, 50 kA maximum discharge current and integrated remote indication.
£171.36
The Mersen 44020421, also known as the K2-4P440-M, is a high-performance Type 2 surge protection device (SPD) designed to protect low-voltage electrical installations against transient overvoltages caused by indirect lightning activity, utility disturbances and electrical switching events. Part of the Mersen Surge-Trap® K2 Series, this four-pole, pluggable SPD is suitable as a second level of surge protection in industrial and commercial power distribution systems.
The K2-4P440-M has a maximum continuous operating voltage of 440 V AC and is designed for 400/690 V AC TNS systems. Its four-pole 4+0 protection configuration provides protection between the live conductors and protective earth, helping safeguard switchgear, automation equipment, motor controls and other sensitive electrical systems.
With a nominal discharge current of 20 kA and a maximum discharge current of 50 kA, the Mersen 44020421 offers dependable protection against damaging 8/20 µs surge currents. An integrated remote indication microswitch enables connection to PLCs, alarms, SCADA platforms or building management systems, while the visual status indicator supports fast local inspection.
Transient overvoltages can originate from nearby lightning activity, utility switching, transformer operation and the switching of motors or other inductive loads. Although these events may last only a fraction of a second, they can damage power supplies, PLCs, variable-speed drives, instrumentation and communication equipment.
The Mersen K2-4P440-M diverts surge current away from connected equipment while its integrated microswitch provides remote status information. The contact can be connected to an alarm circuit, PLC, SCADA platform or building management system, enabling maintenance personnel to identify an end-of-life condition without opening the distribution board.
| Voltage | 400 V |
|---|---|
| Phase | Three Phase |
| Manufacturer | Mersen |
| Series | Surge-Trap® K2 Series |
| Model | K2-4P440-M |
| Manufacturer part number | 44020421 |
| EAN / GTIN | 8435297890010 |
| Product type | Surge protection device |
| IEC SPD classification | Class II |
| EN SPD classification | Type 2 |
| UL SPD classification | Type 1 Component Assembly |
| Format | Pluggable |
| Internal configuration | 4+0 |
| Number of poles | 4 |
| Nominal operating voltage | 400/690 V AC |
| Nominal frequency | 50 / 60 Hz |
| Maximum continuous operating voltage, Uc | 440 V AC |
| Nominal discharge current, In | 20 kA |
| Maximum discharge current, Imax | 50 kA |
| Surge waveform | 8/20 µs |
| Protection modes | L-PE / N-PE |
| System configuration | TNS |
| Remote indication | Integrated microswitch |
| Remote contact rating | 250 V AC at 0.5 A / 30 V DC at 1 A |
| Status indication | Green operational / not green replace |
| Protection rating | IP20 |
| Mounting type | DIN rail |
| Connection torque | 3 N·m |
| Solid conductor capacity | 1.5–35 mm² |
| Stranded conductor capacity | 1.5–25 mm² |
| Remote indication conductor capacity | 0.5–1.5 mm² |
| Operating temperature | -40 to +85 °C |
| Operating humidity | 5–95% |
| Maximum installation altitude | 4,000 m |
| Housing material | PA6 CT1 and PA66 CT1 |
| Housing colour | Grey, RAL 7035 |
| Flammability rating | UL94 V-0 |
| Approximate weight | 0.456 kg |
| RoHS compliant | Yes |
| HS Code | 85363090 |
| Country of Manufacture | Spain |
The Mersen 44020421 is a Type 2 surge protection device designed to protect 400/690 V AC TNS electrical installations and connected equipment against transient overvoltages.
The K2-4P440-M includes an integrated microswitch for remote status indication. The standard K2-4P440 provides local visual indication but does not include the remote monitoring contact.
The device has a nominal discharge current of 20 kA and a maximum discharge current of 50 kA using an 8/20 µs surge waveform.
The Mersen 44020421 is designed for 400/690 V AC TNS systems and uses a four-pole 4+0 internal protection configuration.
An integrated volt-free microswitch changes state according to the condition of the SPD. It can be connected to an external alarm, PLC, SCADA platform or building management system for remote monitoring.
Yes. The pluggable design allows individual protection cartridges to be replaced without removing the complete DIN rail base from the electrical panel.
Mersen Surge-Trap® K2 Series devices provide dependable protection against transient overvoltages while supporting electrical reliability, equipment availability and preventative maintenance in demanding industrial and commercial installations.
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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...