SIEMENS GERMANY SVP SURGE VOLTAGE PROTECT GAS DISCHARGE IN BANGALORE

DC spark-over voltage (type-dependent) 70 to 5000 V Impulse discharge current (8/20 µs wave) up to 40 kA Typical applications Buried cables and PBXs in densely populated areas and main distributors The electrical properties of a gas discharge path depend mainly on environmental parameters such as gas type, gas pressure, humidity and pollution. Stabilized conditions can only be obtained if the discharge path is shielded against these environmental influences. This requirement determines the construction principle of the surge arrester (see figure 1). A proven technique of connecting insulator and electrode ensures hermetic sealing of the discharge region. Type and pressure of the gas in the discharge region can be optimized in this way. Argon and neon are predominantly used for Siemens gas arresters since these rare gas types ensure optimum electrical characteristics throughout the entire service life. An activating compound is applied to the effective electron surfaces of the electrodes, themselves seperated by less than 1 mm, to accelerate the electron emission and to guarantee the stability of the ignition voltage even after repeated current loads. Siemens surge arresters feature the optimum relationship between size, impulse discharge capability and longer than average service life. Protection principle Generally, a spark-over arises if surge voltages occur which exceed the electric strength of a system’s insulation. This discharge limits the surge voltage and reduces the interference energy in a short period of time. The thereby ignited arc with its high current handling capability prevents a further rise in surge voltage due to its approximately constant, low arc voltage of some 10 V. This natural principle of limiting surge voltages is utilized by gas-filled arresters.