Surge Protective Device

Surge is a transient wave of current, potential, or power in an electric circuit. (IEEE Standard C62.41.1-2002)

Surge are commonly generated from outside the facility such as lightning or inside the facility including switching of electrical loads and equipment malfunction. Surges are generally measured in microseconds, surges are brief overvoltage spikes or disturbances on a power waveform that can damage, degrade, or destroy electronic equipment, that is the reason to use surge protective devices for protection.

A surge protective device (SPD) is a protective device designed to protect electrical equipments, etc by limiting transient overvoltages, diverting or limiting surge current. SPDs are usually connected in parallel on the power supply circuit of the loads that is has to protect.

The core component of SPDs is a nonlinear component. SPDs can be categorized as voltage switching type SPD (Use GDT) and voltage limiting type SPD (Use MOV) based on its core component.

Metal oxide varistors (MOVs) and gas discharge tubes (GDTs) are two core components commonly used in manufacturing SPDs. MOVs limit voltages to about 3 to 4 times the normal circuit voltage by diverting surge current elsewhere to protect the electrical loads. GDTs create an effective short circuit if any electrical energy is present, and GDT will short this until all electric current sufficiently diminishes. Thus MOVs and GDTs are able to limit transient overvoltage, divert or limit surge current.

Smart Surge Protective Device
Smart Surge Protective Device

1. Real-time monitoring of the operational status of Surge Protective Devices(SPDs)
2. Real-time monitoring of lightning and surge
3. Networking functions
4. Unattended operation

Product List

Smart Surge Protective Device
Smart Detector

1. Real-time monitoring of lightning and surge
2. Networking functions
3. Unattended operation

Product List

Surge Protective Device for Photovoltaic
New Energy System

Photovoltaic System
1. Off-grid system: Minimum DC voltage 100VDC
2. On-grid system: Maximum DC voltage 1200VDC

Wind Energy System
1. Wind gen side: MOV + GDT application schema
2. Wind grid side: Class I, Class II combination application schema


Surge Protective Device for AC Power Supply
AC Power Supply System

1. DIN Rail mount
2. Field replaceable phase modules
3. Finger-safe design – IP20 rating
4. Built-in visual status indicator
5. Remote indicator with 3 pin COM/NO/NC contacts
6. Easy installation or retrofit
7. Fail-safe / self-protected design


Surge Protective Device for DC Power System
DC Power System

1. Applied to DC distribution cabinet, 1ns response time
2. DC high voltage power supply system, maximum 1500VDC
3. Light-current systems 48VDC system
4. Series connection protection


Surge Protective Device for Power over Ethernet (POE)
Ethernet & PoE System

1. UL certified
2. 10/100/1000M adaptive network
3. Enhanced PoE protection mode feature
4. Different structure design
5. Wall installation, outdoor waterproof installation
6. More protection mode options

Product List

Data Signal System
Data & Signal System


Product List

Surge Protective Device for Data & Control
4~20mA & RS485 Control System

1. 4-20mA, 0-5V, RS485, Control Signal
2. Din rail, G-profile Din rail installation
3. Wall installation, outdoor water-proof enclosure installation

Product List

19"-rack Application & Power Distribution Unit (PDU)

1. Perfect structural design, height: 1U (44.5mm), depth: 89mm
2. Exquisite craftsmanship, pretty and durable mounting ears
3. Black aluminum alloy oxidation, artistic color, sleek edge
4. Independent grounding terminal, superior surge protection features
5. Modular-structure and Multi-function customized combination, standard 19-inch length, more options of customized lengths are available