SuppresSurge Freestanding Protectors provide a convenient way to provide overvoltage protection for applications with four lines or two loops. The classical three element, high energy, primary overvoltage protection ciruits are packaged in a free standing housing or case(C version) with screw terminal interfaces. The E versions have the same circuitry and interface but are encapsulated for high vibration environments. The 232, Tel50 and Tel185 have four separate lines in each housing. The 422, 485 and 420L's have dedicated line to line protections added for two pairs or loops of protection circuits per unit. Some additional special purpose freestanding protectors are shown under miscellaneous protectors on page 27.

How To Choose a Protector

For RS232, RS422 or RS485 data lines select the associated product, i.e., 232C or E, 422C or E or 485C or e respectively. For 4-20 mA loops, select a 420LXXX protector with a coltage rating equal to or greater than the system maximum operating voltage.
For telephone lines, select a TEL50C or E for digital lines with an operational voltage of 48 Volts dc; select a TEl185C or E for an analog system having the 90vrms ringing voltage superimposed upon the 48 Volts dc central office supply voltage.