What is a gas plasma arrestors?
” ” Inside a surge protector with line-conditioning chokes. Another common surge protection device is a gas discharge arrestor, or gas tube. These tubes do the same job as an MOV — they divert the extra current from the hot line to the ground line.
What does a gas arrestor do?
In a gas discharge arrestor, an inert gas sits between the hot line and ground line connecting an electric appliance to the wall. Once the gas becomes ionized, it can now easily conduct electricity. The gas diverts the extra voltage into the ground line and lets the proper voltage continue to flow to the appliance.
How does a gas discharge lightning arrestor work?
Gas discharge protectors work as voltage filters. During normal operation, the gas inside the tube is and remains inert. Signal can pass through the surge arrester to the equipment. When a lightning strikes the infrastructure, current will flow through the cable to the surge protector.
How does an arrestor work?
Arresters are typically installed near critical appliances or points of entry, such as an electrical panel or near a generator. When potentially dangerous lightning strikes, the arrester activates and diverts the lightning to ground, where it will disperse harmlessly.
What are gas discharge tubes used for?
Gas Discharge Tubes (GDTs) are used to protect personnel and sensitive equipment from hazardous transient voltages. Bourns® GDTs are used in primary and secondary applications and can withstand multiple applications of high surge current energy in excess of 25 KA.
What is meant by gas discharge?
noun. A flow of electricity through a gas, typically accompanied by emission of light; a body of gas in which this is occurring.
How do gas discharge tubes fail?
While these gas discharge tubes are rugged components, they can be damaged by extreme exposure to lightning. The typical failure mode is an increase in voltage at which the GDT conducts (or protects), or complete catastrophic failure for severe exposures.
What inert gas can be used in a gas arrestor?
Air can be used in some low-demanding applications. Nitrogen at relatively high pressure tends to be used in surge arresters, due to its short build-up time, giving the tubes fast response time to voltage surges.
What does a gas discharge tube do?
Gas discharge tubes dissipate voltage transients through a contained plasma gas. They have high insulation resistance plus low capacitance and leakage to ensure minimal effect on normal operation of equipment.
How do I choose a GDT?
The GlobalSpec SpecSearch Database contains the ability to specify important performance characteristics when selecting a GDT.
- Capacitance range is the range of ability a gas discharge tube has to hold an electrical charge.
- Sparkover voltage is the main characteristic defining a GDT.