Description

Telebyte 22NX Lightning Surge Protector for RS-422 AND RS-485 Simple Type: Surge Protective Device he Model 22NX Lightning Sponge is designed to accommodate these transients, slow them down and redirect them to a low impedance path to earth ground. RS-422/RS-485 is a low voltage, high speed interface. Protection of these RS-422/RS-485 lines is accomplished by using the 4-wire Model 22NX. It limits the voltage to approximately 7.5 Volts and passes signals whose data transfer rate can exceed ten million bits per second. The protection circuits incorporate 3 separate stages of limiting high voltage transients, gas tubes and two stages of avalanche diodes. The DC series resistance is limited to approximately 5 Ohms and the response time is measured in nanoseconds. It is good practice to install a Model 22NX on each end of the 4-wire transmission line. The output voltage is limited to ±7.5 volts for the Model 22NX.The Model 22NX provides 4-wire screw terminals on both ends for terminating the 4-wire lines. An additional screw terminal is provided to make the connection to earth ground. This wire should be at least #12 gauge or larger and be as short as possible. It will conduct the surge to earth ground (power ground or water pipe).