Mersen Surge Protector Type 2 SPD 3 Pole 480 Volt 20KA TNC
Mersen STPT2-40K320V-3P Type 2 surge protection device with 40 kA Imax, 277 / 480 V AC nominal operating voltage, 320 V AC maximum continuous operating voltage, 3+0 TNC configuration and pluggable DIN rail design.
This product has been discontinuedA direct replacement is available below.
Why Choose the Mersen STPT2-40K320V-3P Surge Protection Device?
The Mersen STPT2-40K320V-3P (Part Number 83020136) is a high-performance Type 2 surge protection device (SPD) designed to protect three-phase low-voltage electrical installations against transient overvoltages caused by lightning activity and electrical switching events. As part of the Mersen Surge-Trap® Pluggable STPT2 Series, it provides reliable protection for industrial, commercial and infrastructure electrical systems.
Featuring a 40 kA maximum discharge current (Imax), 320 V AC maximum continuous operating voltage (Uc) and pluggable modular construction, this SPD supports fast installation, simple cartridge replacement and dependable long-term protection in electrical distribution panels.
Designed for 277 / 480 V AC three-phase systems with a 3+0 TNC configuration, the STPT2-40K320V-3P is well suited to protecting automation equipment, machine control panels, commercial switchboards, building services and critical low-voltage electrical installations.
Key Advantages
Reliable Type 2 surge protection device for three-phase low-voltage systems.
40 kA maximum discharge current for effective transient overvoltage protection.
320 V AC maximum continuous operating voltage for 277 / 480 V AC installations.
Pluggable cartridge design simplifies replacement and maintenance.
Compact 3-pole DIN rail mounting format for distribution boards and control panels.
Suitable for industrial, commercial and infrastructure applications.
Key Features
Mersen Surge-Trap® Pluggable STPT2 Series.
Type 2 / Class II surge protection device.
40 kA Imax maximum discharge current using 8/20 μs waveform.
20 kA nominal discharge current (In).
277 / 480 V AC nominal operating voltage.
320 V AC maximum continuous operating voltage (Uc).
Three-phase, 3+0 TNC configuration.
3-pole, 3-module pluggable construction.
Visual indication system for device status.
DIN rail mounting for electrical panels.
Reliable Surge Protection for Three-Phase Installations
Type 2 surge protection devices are installed within electrical distribution systems to help limit transient overvoltages before they reach sensitive connected equipment. This helps reduce equipment damage, minimise downtime and improve the reliability of critical electrical systems.
The Mersen STPT2 pluggable range combines high discharge capability with replaceable cartridges and clear device status indication, making it suitable for preventative maintenance in control panels, low-voltage switchgear and commercial distribution boards.
Typical Applications
Three-phase electrical distribution boards.
Industrial automation systems.
Machine control panels.
Commercial switchboards.
Building management systems.
Telecommunications and data infrastructure.
Water treatment facilities.
Low-voltage installations requiring 277 / 480 V AC surge protection.
Technical Specifications
Voltage
480 V
Phase
Three Phase
Manufacturer
Mersen
Series
Surge-Trap® Pluggable STPT2 Series - 40kA
Model
STPT2-40K320V-3P
Item number
83020136
Product type
Surge protection device
SPD type
Type 2 / Class II
UL SPD type
Type 2 Component Assembly
Maximum discharge current
40 kA Imax (8/20 μs)
Nominal discharge current
20 kA In (8/20 μs)
Nominal operating voltage
277 / 480 V AC
Maximum continuous operating voltage
320 V AC
System configuration
3+0 TNC
Number of poles
3 poles
Module width
3 modules
Format
Pluggable
Mounting type
DIN rail
Protection rating
IP20
RoHS compliant
Yes
EAN / UPC
8435297850977
HS Code
85363090
Country of Manufacture
Spain
Frequently Asked Questions
What is the Mersen STPT2-40K320V-3P used for?
It is used to protect three-phase low-voltage electrical installations and connected equipment against transient overvoltages caused by lightning activity and switching events.
What type of surge protection device is this?
The STPT2-40K320V-3P is a Type 2 / Class II surge protection device for electrical distribution and control systems.
What is the maximum discharge current rating?
This SPD has a 40 kA Imax maximum discharge current rating using an 8/20 μs waveform.
What voltage is this model designed for?
It is designed for 277 / 480 V AC three-phase systems with a 320 V AC maximum continuous operating voltage.
How is this surge protection device installed?
The device is designed for DIN rail mounting and uses a pluggable modular format for straightforward installation and maintenance.
Trusted by Electrical Engineers Worldwide
Mersen Surge-Trap® surge protection devices are trusted by panel builders, electrical contractors and maintenance engineers to protect critical low-voltage installations from damaging transient overvoltages.
Voltage
480 V
Phase
Three Phase
Manufacturer
Mersen
Series
Surge-Trap® Pluggable STPT2 Series - 40kA
Model
STPT2-40K320V-3P
Item number
83020136
Product type
Surge protection device
SPD type
Type 2 / Class II
UL SPD type
Type 2 Component Assembly
Maximum discharge current
40 kA Imax (8/20 μs)
Nominal discharge current
20 kA In (8/20 μs)
Nominal operating voltage
277 / 480 V AC
Maximum continuous operating voltage
320 V AC
System configuration
3+0 TNC
Number of poles
3 poles
Module width
3 modules
Format
Pluggable
Mounting type
DIN rail
Protection rating
IP20
RoHS compliant
Yes
EAN / UPC
8435297850977
HS Code
85363090
Country of Manufacture
Spain
No documents available for this product.
Delivery
We offer fast UK delivery on all stocked items. Orders placed before 3pm Monday to Friday are eligible for next-day delivery.
Standard delivery: 2–3 working days
Next-day delivery: available on in-stock items when ordered before 3pm
Express options available — contact us for details
Returns
If you need to return an item, please contact our sales team within 30 days of receipt. Items must be returned unused in their original packaging.
Our service agreements are built to support long term procurement relationships. By working closely with engineering teams and procurement departments, we help streamline purchasing processes while ensuring consistent access to critical components and sourcing support when it matters most.
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Stock lines ready to ship
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Same day dispatches
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Customers supported
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LED Controls is a specialist distributor of factory automation and industrial controls, supplying OEMs, machine builders, panel builders and end users throughout the UK and worldwide. As a trusted UK distributor for many of the world’s leading automation manufacturers, we provide industrial control products, technical expertise and bespoke automation solutions backed by outstanding customer service.
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...