3A400 Pilot Wire Supervision System

The 3A400 concept is based on the need to improve the performance of existing pilot wire protection schemes by increasing reliability & availability as well as adding an over current guard function. With the 3A400 this can be achieved at considerably lower cost than the replacement of the existing proven protection relays & change over to a fibre optic communication channel. A revised protection scheme using the 3A400 comprises the following functional elements:

• The existing current differential protection relays;

• Pilot wire supervision system to monitor the pilot wire integrity;

• High voltage rated series capacitors to isolate the DC supervision voltages from the circulating AC protection signals; Shunt resistor to increase fault current setting;

• Pilot wire fail alarm contact provided at both ends of the protection scheme; Self supervision circuitry to monitor & alarm in event of system failure;

• A control panel for setting & displaying the system status.

Features

• Integrated pilot wire supervision system for current differential protection schemes
• Operates using conventional metallic pilot wire (0 to 2K Ohm pilot resistance)
• Inherent 5KV or 15KV isolation No external components required
• Integrated pilot protection discrimination timer
• Extensive self supervision features to ensure functional integrity
• Supervision alarm contacts provided at both ends of pilot
• Simple to set up & commission
• Flush or 4U 19" rack mounting
• M4 screws for control wiring
• M5 studs for pilot cable connection with clear protective isolation cover
• Made in Australia