2015-35-SMC-RPLF

Gas Discharge Tube Arresters (GDT) are designed to protect electrical equipment from destructive surges of energy that can result from lightning strikes or power surges. GDTs are generally used to protect circuits in three distinct ways: as surge protection devices (SPD), voltage limiting arresters (VLA), and surge diverters (SD).

FIRST-Surge protection devices (SPD) are designed to reduce the damage caused by voltage surges and transients, and act as a “lightning guard”. The main components of an SPDA are a gas discharge tube, a voltage-limiting element, and a spark gap. The surge current is directed to the earth conductor by the gas discharge tube. The voltage-limiting element allows the voltage to the protected equipment to be limited and the spark gap keeps the gdt from overloading.

SECOND-Voltage limiting arresters (VLA) are designed to reduce the risk of electrical shock by limiting the voltage from the source to the protected equipment. The components of a VLA are a surge limiting element, a surge diverter, and a voltage limiter. The surge limiting element limits the magnitude of the surge voltage by directing it away from the system. The surge diverter shorts the surge high voltage and maintains the voltage levels at the protected equipment. The voltage limiter provides a limited current so that the system can be properly grounded.

THIRD-Surge diverters (SD) are used to protect against surges and transients by diverting most of the surge energy away from the protected equipment. The main components of an SD are a surge limiting element, an impedance device, and a spark gap. The surge limiting element reduces the magnitude of the surge voltage, while the impedance device redirects the surge current away from the equipment. The spark gap provides a path for the diverted energy.

GDTs are typically made of a solid insulating material, such as a ceramic, filled with a gas mixture that is electrically conductive when ionized. The GDT is connected in parallel to the electrical equipment and the gas in the tube is ionized by an electric field, which limits the voltage across the tube. As the gas in the tube ionizes, it creates a conductive path, allowing current to flow through the device and to the earth conductor. As the current passes through the device, it causes it to heat, which eventually causes the gas to collapse and the tube to break open, diverting the current away from the protected equipment.

The use of GDTs for surge protection has been increasing in recent years due to their excellent performance and reliability. GDTs offer several important advantages over traditional surge protection devices, such as lower capacitive and inductive reactance, low power dissipation, higher voltage protection levels, and the ability to protect multiple voltage systems.

In summary, GDTs are an ideal solution for protecting electrical equipment from destructive voltage surges due to their superior protection capabilities, low cost, and low maintenance requirements. GDTs provide an effective and reliable method of surge protection for both residential and commercial applications.