420LB60

Features:

Designed for 4-20mA Current Loops
Automatic Reset - Will Not Interrupt Service
Permanent Two-Stage Line Pair Protection
Line-to-Ground (Common) & Line-to-Line (Differential) Protection
Subnanosecond Response Time
Effective Against Lightning, Inductive Switching & ESD


Application

Multi Process Control Loops
Fire & Security Systems
Petro-Chemical Plants
Refineries & Tank Farms


Specifications




Description

The 420LE/B series is a two stage transient voltage protector providing primary and secondary protection against lightning, inductive switching and electrostatic discharge (ESD) transient threats.  The first stage diverts the transient current through the ground terminal return path and the second stage clamps the voltage to a safe level without interruption of service.

The 420LE/B series is designed to protect data lines from  differential (line to line) and common mode (line to ground) transients.Terminals 1 and 2, 3 and 4 for the 420LE and pins 2 and 3, 4, and 5 for the 420LB are designated as line pairs.  Each line pair is referenced to ground.  A transient voltage suppressor is connected across each line pair for differential mode protection.  Each line pair is referenced to ground.

This 420LE/B series can also be used on telephone, signal/data lines, security, timing and control interface circuits.  For most applications,the 420LE/B series should be located as close as possible to the equipment being protected.  A low impedance grounding system is impor-tant to maintain a low voltage clamp between the line-to-ground connection.