SL1003A300SM

Gas Discharge Tube Arresters (GDT) are designed to protect circuits and electronic elements from overvoltages arising from nearby lightning flashes. They are also referred to as surge arresters, surge protectors, or lightning arrester. A GDT operates by providing a low impedance path to ground for surge current and by allowing a limited amount of current to flow between the points it protects and ground.

The SL1003A300SM is a gas discharge tube arrester specifically manufactured to present a high surge current capability while maintaining a low series resistance. This product is designed for use on UL classified intermediate circuit and control circuit voltage applications like 480VAC or 600VAC (UL 489 standard).

The working principle of the SL1003A300SM gas discharge tube arrester is based on a semi-conductor gas discharge tube (GDT) enclosed in a non-arcing, low resistance enclosure and provided with an insulated mica-based support structure. The SL1003A300SM is designed to provide a reliable short circuit for large surge currents. A spark gap assembly is connected between the two main electrodes and between the mica support structure and ground. The gap caused by the spark gap assembly creates a high voltage gradient along with an ionized tunnel that allows the surge current to pass through the GDT.

In normal operating conditions, the gap between the two main electrodes of the GDT is so small that a few electrons are able to pass through it in order to maintain a balance. This current flow is limited by the series resistance of the GDT, which acts as a stabilizing element. The series resistance also ensures that the average current flow through the GDT is limited, thus preventing the breakdown of the internal dielectric material.

In an overvoltage situation, the gap between the two main electrodes gets larger and the gradients of the electric field become stronger, leading to the creation of an arc between the two terminals. This process is known as the sparkover. Once the sparkover is reached, the entire energy of the surge is dissipated within the GDT enclosure. The SL1003A300SM has been specifically designed to ensure that the sparkover stays within the limits of protection.

The SL1003A300SM has several features that make it well-suited to its application field. Due to its high surge current capability and low series resistance, it is especially well-suited for AC power supplies, intermediate circuits, and control circuits. The low series resistance also makes it ideal for use in high-voltage environments. It is also highly resistant to lifetime degradation due to its robust mica-based support structure.

In summary, the SL1003A300SM gas discharge tube arrester operates on the principle of a spark gap that allows the surge current to pass through the GDT while limiting the current through the protective device itself. This makes it well-suited to its application field in AC power supplies, intermediate circuits, and control circuits, as well as in high-voltage environments. The SL1003A300SM is also highly resistant to lifetime degradation.