Applications

? 4 to 20 mA sensors and controllers

? Industrial process control

? HART Street light controllers

? Toll booths, drawbridges, railroad crossing gates &

signals

? Pulse input circuits

Features

? Dual Channel

? Three-Stage Protection

? Weather resistant enclosure

? Screw Terminal Blocks

? Available in 12V, 15V and 24V models

Description

The AL-CL2-xx series are high performance 3-stage outdoor protectors that provide superior protection of

differential or common mode lines from transients and surges. These units will protect two 4-20 mA circuits.

The first stage is comprised of a differential gas discharge tube. Stage two is a pair of current limiting series

resistors and the final stage is a low capacitance diode array. The use of three terminal differential gas discharge

tubes provides superior common and differential mode protection against

conducted transients versus the use of lower cost two terminal tubes. The

second stage series resistance limits the power dissipation of the fast diode

clamp array in the third stage. This allows time for the slower but higher

power gas tubes to flash over. The diode array clamps the leading edge of

fast transients to safe levels until the high power gas tubes turn on. This

eliminates the damaging leading edge spike that single stage gas tube

protectors let leak through. The diode array’s low capacitance assures that

the suppressor will not degrade the high-speed signals. The 3-stage design

can handle higher-level transients than a protector that uses only diodes.

For more complete surge protection of data lines, the use of two units is recommended, one at each end of the

line.

The compact weather resistant housing features a lockable hinged cover and mounting holes are provided on the

rear of the enclosure for mounting. The two cable grommets may be adjusted to cable size and are removable.