Standard delivery
£8 ex VAT · free over £200UK parcel delivery is £8 ex VAT, or free on orders over £200 ex VAT.
Heavier items may be charged at a weight-based or pallet rate, shown at checkout.
K2-3P440 Mersen Surge Protector Type 2 SPD 3 Pole 400/690 Volt 20KA IT
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.
£84.12
Why Choose the Mersen 44020308 K2-3P440 Surge Protection Device?
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.
Key Advantages
- Reliable Type 2 surge protection for three-phase 400/690 V electrical systems.
- 50 kA maximum discharge current provides excellent transient overvoltage protection.
- Suitable for TN-C systems and compatible with 400 V IT networks.
- Replaceable pluggable cartridges simplify servicing and maintenance.
- Visual status indication allows rapid inspection.
- Compact three-module DIN-rail installation.
Key Features
- Mersen Surge-Trap K2 series.
- Type 2 / Class II surge protection device.
- Three-pole (3+0) configuration.
- 400/690 V AC nominal operating voltage.
- 440 V AC maximum continuous operating voltage (Uc).
- 20 kA nominal discharge current (In).
- 50 kA maximum discharge current (Imax).
- Protection mode: L-PE(N).
- Dynamic thermal disconnection.
- Visual operating status indication.
- Replaceable plug-in cartridges.
- DIN-rail mounting.
Reliable Protection for 400/690 V Three-Phase Systems
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.
Typical Applications
- 400/690 V TN-C distribution boards.
- 400 V IT electrical installations.
- Industrial switchgear.
- Motor control centres.
- Commercial power distribution systems.
- PLC and automation control panels.
Technical Specifications
Tick the specs you need, then view products that match.
| Voltage | 690 V | |
|---|---|---|
| Phase | Three Phase | |
| Poles | 3-pole | |
| Device Type | Surge protection device | |
| SPD Type | Type 2 | |
| Earthing System | IT, TN-C | |
| Nominal Discharge Current (In) | 20 kA | |
| Remote Signal | No | |
| 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 | TN-C (also suitable for 400 V IT) | |
| 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 |
Frequently Asked Questions
What is the Mersen 44020308 used for?
The Mersen 44020308 protects three-phase 400/690 V electrical installations from transient overvoltages caused by lightning activity, switching events and inductive loads.
What type of surge protection device is the K2-3P440?
It is a Type 2 / Class II surge protection device designed for secondary surge protection in low-voltage electrical installations.
Which electrical systems are compatible with this SPD?
The K2-3P440 is designed for TN-C 400/690 V systems and is also suitable for 400 V IT network configurations.
What discharge current can the device withstand?
The device provides a 20 kA nominal discharge current and a 50 kA maximum discharge current using the standard 8/20 µs surge waveform.
Can the protection cartridges be replaced?
Yes. The pluggable construction allows the protection cartridges to be replaced without removing the complete DIN-rail base, reducing maintenance time.
Trusted Surge Protection from Mersen
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.
