Xiamen SET Electronics Co., Ltd.
The Gas Discharge Tube(GDT) is a protective device which is filled with certain proportion of noble gas, or mixed gas or other discharge media in the space between metal electrodes and metalized ceramics,and then sealed at high temperature to form a single-gap or multi-gap switch type protective device.When the protected circuit or equipment suffers to surge, GDT will change from high impedance state to low impedance state and release the surge energy to reduce the residual voltage of the circuit, and then protect the equipment or humanbody from the hazard of transient overvoltage.
SETsafe | SETfuse GDT products have a voltage range of 70 to 4500 V and a surge current (at 8 / 20 μs) range of 0.5 to 200 kA. It is widely used in the overvoltage protection of signals, power supplies, and various ports; safety certificates include UL, cUL, TUV, and it also meets RoHS & REACH requirements.

Vs
D.C. Spark-over Voltage
The voltage at which the GDT sparks over with slowly increasing d.c. voltage.
— (IEC 61643-311)
V
Impulse Spark-over Voltage
The highest Voltage which appears across the terminals of a GDT in the period between the application of an impulse of given wave-shape and the time when current begins to flow.
— (ITU-T K.12)
Va
Arc Voltage
Voltage drop across the GDT during arc current flow.
— (IEC 61643-311)
Vgl
Glow Voltage
The peak value of the voltage drop across the GDT when a glow-current is flowing, It is sometimes called the glow mode voltage.
— (ITU-T K.12)
8/20 μs
8/20 Current Impulse
Current impulse with a nominal virtual front time of 8 µs and a nominal time to half-value of 20 µs.
— (IEC 61643-11)
1.2/50 μs
1.2/50 Voltage Impulse
Voltage impulse with a nominal virtual front time of 1.2 µs and a nominal time to half-value of 50 µs.
— (IEC 61643-11)
I
Alternating Discharge Current
The r.m.s. value of an approximately sinusoidal alternating current passing through the GDT.
— (ITU-T K.12)
In
Nominal Discharge Current
Crest value of the current through the GDT having a current waveshape of 8/20 µs.
— (IEC 61643-11)
Imax
Maximum Discharge Current
Crest value of a current through the GDT having an 8/20 µs waveshape and magnitude according to the manufacturers specification. Imax is equal to or greater than In.
— (IEC 61643-11)
Through Hole, Surface Mount
Street Lighting (Power Supply, N-PE Protection in AC Power)
Application SETsafe | SETfuse Product Series:
SE Series
SF Series
New Energy (WLAN xDSL, Power Supply, N-PE Protection in AC Power)
Application SETsafe | SETfuse Product Series:
SE Series
SC Series
Communication (WLAN xDSL, CATV, MDF, BTS(Base Station), Antenna and RF, N-PE Protection in AC Power)
Application SETsafe | SETfuse Product Series:
SX Series
SW Series
TZ Series
SE Series
SC Series
SPA Series
SPB Series
SPC Series
SPJ Series
SPI Series
Security Monitoring (WLAN xDSL)
Application SETsafe | SETfuse Product Series:
SX Series
TZ Series
Medical (WLAN xDSL)
Application SETsafe | SETfuse Product Series:
SN Series
TZ Series
Home Appliances (Power Supply, Consumer Electronics)
Application SETsafe | SETfuse Product Series:
SE Series
SF Series


SETsafe | SETfuse Quality Policy
Provide Industry-Leading Products
Raw-materials Supplier
Select critical raw materials: Must be from a manufacturer with quality management system (ISO9001, IATF16949) certification.
Annual or Quarterly Audits.
IQC (Incoming Quality Check)
AQL(MIL-STD-105E), Dimensions, Function, Visual Inspection, RoHS & REACH Test.
Document
Formulate corresponding incoming inspection specifications (01-QA-06-xxx) for each key material according to design data such as material technical indicators.
Testing Equipment and Tools
Projector, Tool Microscope, Salt Spray Tester, Universal Material Testing Machine, Spectrum Analyzer, etc.

Manufacturing Process
Online Inspection and Testing (Function 100% Automatic Testing).
Document
Process Flow Chart.
Failure Mode and Effects Analysis (FMEA).
Quality Control Flow Chart (QCFC).
Standard Inspection Procedure (SIP).
Work Instruction (WI).
Online Testing and Inspection
D.C. Spark-over Voltage Test (@100V/s) (100% Automatic Testing).
Insulation resistance Test system (100% Automatic Testing).
etc.

IPQC (In Process Quality Control) Inspection
AQL(MIL-STD-105E), Dimensions Inspection, Function Test, Visual Inspection.
FQC ( Final Quality Control)
AQL(MIL-STD-105E), Dimensions Inspection, Function Test, Visual Inspection, RoHS & REACH Test.
Reliability Test
Test specification (01-TE-01-xxx).
Including 17 items of appearance requirements, Electrical Performance, Mechanical Performance, Soldering Performance and Environmental test. e.g.
D.C. Spark-over Voltage Test(@100V/s)
Insulation resistance Test.
Impulse Discharge Current Test.
Low Temperature Test
High Temperature Test
etc.
OQC (Outgoing Quality Control)
AQL(MIL-STD-105E), Packaging, Labeling, Quantity Inspection.
Agency
Agency (Safety Certificate) Annual, Quarterly Audits.
Management System
ISO9001, (TUV approved and issued certificate).
ISO14001, ISO45001, etc.
Click to view the certificate
Environmental
RoHS & REACH Compliant.
SETsafe | SETfuse

Usage
1. Do not operate GDT in power supply networks, whose maximum operation voltage exceeds the minimum spark-overvoltage of the GDT.
2. The GDT may become hot in the event of longer periods of current stress (burn risk). In the event of overload the connectors may fail or the component may be destroyed.
3. If the contacts of GDT are defective, current load can cause sparks and loud noises.
4. When air pressure is from 55 kPa to 106 kPa. The relative altitude shall be +5000 m to –500 m.
Replacement
The GDT is a non-repairable product for safety sake, please use equivalent GDT for replacement.
Storage
The packaged GDT shoud be placed in a dry, ventilted and non-corrosive environment.
Installation Position
Do not install the GDT in a touchable position.
Mechanical Stress
Do not take violent action such as knocking when assembling, to avoid product failure.
Gas Discharge Tube (GDT) Catalog
View PDF
