Section 5
Protection relay operation
5.1
Normal operation
In a normal protection relay use situation, the basic operation includes monitoring and
checking procedures.
•
Monitoring measured values
•
Checking object states
•
Checking function setting parameters
•
Checking events and alarms
All basic operations can be performed via the LHMI, WHMI or with PCM600.
For more information, see the PCM600 documentation.
5.2
Disturbance identification
Disturbances and their causes can be identified by indicator LEDs: Normal, Pickup and
Trip. During normal operation, the Normal LED is steady green.
Table 17:
Disturbance indications
LED
State
Description
Pickup LED
Yellow, steady
Protection picked up
Pickup LED
Yellow, flashing
Protection function blocked
Trip LED
Red, steady
Protection tripped
Normal LED
Green, flashing
Internal fault
Further actions to be taken to identify the disturbance:
1MAC456939-IB D
Section 5
Protection relay operation
620 series ANSI
77
Operation Manual