Digital Overcurrent & Ground Overvoltage & Selective Ground Relay (GDR-AEF01) User's Manual
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Kyongbo Electronics Co., Ltd.
cable with the cross cable supplied with this product together.
4.2.2
RS-485C Communication
To connect to higher level monitoring control system, insulated RS-485 Half Duplex
communication method is provided. This communication method can connect with
multi-drop, and the maximum communication distance is 1.2km. The end part of
RS-485C cable should be connected with 120Ω resistor parallel as shown in the
following figure.
【
Figure 4.3
】
RS-485C Connection Diagram
4.3 Self Diagnosis Function
Self Diagnosis function monitors the operation status of the relay at all times to prevent
abnormal/failure operation of the equipment. If an abnormality is detected, red Error LED
is lighted, and the Self Diagnosis result category in the Self-Diagnosis menu is displayed as
FAIL. Also, when a fault occurs, the operation output of the relay element is blocked
immediately, and it is displayed on LCD and LED until the fault is cleared.
Main diagnosis categories are as follows.
▣
Power Fail
▣
CPU Watchdog Fail
▣
Memory Fail
▣
Value outside Setting