4-2
745 Transformer Management Relay
GE Multilin
4.1 HARDWARE INTERFACE
4 HUMAN INTERFACES
4
4.1.3 LEDS
Front panel indicators are grouped in three columns: RELAY STATUS, which provides information about the state of the
745; SYSTEM STATUS, which provides information about the state of the transformer and the power system; and CONDI-
TIONS, which provides details about abnormal conditions that have been detected. The color of each indicator conveys
information about its importance:
GREEN (G)
indicates a general condition
AMBER (A)
indicates an alert condition
RED (R)
indicates a serious alarm or warning
All indicators can be tested by pressing
while no conditions are active.
4.1.4 LED INDICATORS
a) 745 STATUS
IN SERVICE:
The In Service LED is on when relay protection is operational. The indicator is on only if all of
the following conditions are met:
•
S1 745 SETUP
ÖØ
INSTALLATION
Ö
745 SETPOINTS
: "Programmed"
•
S6 TESTING
Ö
OUTPUT RELAYS
Ö
FORCE OUTPUT RELAYS FUNCTION
: "Disabled"
•
S6 TESTING
ÖØ
SIMULATION X SIMULATION SETUP
Ö
SIMULATION FUNCTION
: "Disabled"
•
No self-test errors which have an effect on protection have been detected
•
code programming mode is inactive
•
factory service mode is disabled
SELF-TEST ERROR:
The Self-Test Error LED is on when any of the self-diagnostic tests, performed either at power-
on or in the background during normal operation, has detected a problem with the relay.
TEST MODE:
The Test Mode LED indicator is on when any of the 745 testing features has been enabled. The indicator is on if any of the
following conditions are met:
•
S6 TESTING
Ö
OUTPUT RELAYS
Ö
FORCE OUTPUT RELAYS FUNCTION
:
"Enabled"
•
S6 TESTING
ÖØ
ANALOG OUTPUTS
Ö
FORCE ANALOG OUTPUTS FUNCTION
:
"
Enabled"
•
S6 TESTING
ÖØ
SIMULATION
Ö
SIMULATION SETUP
Ö
SIMULATION FUNCTION
:
"Prefault Mode", "Fault Mode", or "Play-
back Mode"
•
factory service mode is enabled
DIFFERENTIAL BLOCKED:
The Differential Blocked LED indicator is on when the restrained differential protection feature is enabled but is being
blocked from operating by any of the harmonic restraint features. The indicator is on if the following condition is met:
•
S4 ELEMENTS / DIFFERENTIAL / HARMONIC RESTRAINT
is blocking any phase (see scheme logic)
LOCAL:
The Local LED indicator is on when the 745 is in local mode, i.e. the front panel
key is operational.
MESSAGE:
The Message LED indicator is on when any element has picked up, operated, or is now in a latched state waiting to be
reset. With this indicator on, the front panel display is sequentially displaying information about each element that has
detected an abnormal condition.
NEXT
RESET