Edwards EST SIGA-IM Fault Isolator Module

If a fault occurs, the isolator cuts power to all devices beyond the isolator on the loop as follows:

• a shorty on the line causes all isolators to open within 23 msec.
• at 10 msec intervals, beginning on one side of the Class A circuit nearest the loop controller, the isolators close to provide the next isolator down the line with power
• when the isolator next to the short closes, it reopens within 10 msec.

Once activated, the line fault isolator continuously checks the faulted side of the loop to determine if the short still exists. When the fault is removed, the module automatically restores the entire data loop into the normal condition. The microprocessor in every Signature module provides at least three important benefits - Self-diagnostics and History Log, Automatic Device Mapping, and Fast, Stable Communication.