Model 27A protects all 24 signal lines of the industry standard DB-25 connector against lightning and power surges. Each of the lines contains 600W semiconductor protection circuits that dump
the surges to frame ground, pin 1, the DB-25 connector shell, and the central ground lug of the bottom unit. The devices operate in less than 5 ns, so they are effective against transients. The protector comes in two versions to accommodate the different voltage requirements of EIA-530 (Model 27A1) and RS-232 (Model 27A2) interfaces.
Telebyte Technology Inc.