Relay Maintenance; Phasor Measurement Unit One-Shot - GE L90 Instruction Manual

7 COMMANDS AND TARGETS
PATH: COMMANDS

RELAY MAINTENANCE

COMMANDS
RELAY MAINTENANCE
This menu contains commands for relay maintenance purposes. Commands for the lamp test and order code are activated
by changing a command setting to "Yes" and pressing the ENTER key. The command setting will then automatically revert
to "No". The service command is activated by entering a numerical code and pressing the ENTER key.
The command turns on all faceplate LEDs and display pixels for a short duration. The
PERFORM LAMPTEST
command causes the relay to scan the backplane for the hardware modules and update the order code to
ORDER CODE
match. If an update occurs, the following message is shown.
There is no impact if there have been no changes to the hardware modules. When an update does not occur, the
message will be shown.
CODE NOT UPDATED
The is used to perform specific L90 service actions. Presently, there is only one service action available.
SERVICE COMMAND
Code "101" is used to clear factory diagnostic information stored in the non-volatile memory. If a code other than "101" is
entered, the command will be ignored and no actions will be taken. Various self-checking diagnostics are performed in the
background while the L90 is running, and diagnostic information is stored on the non-volatile memory from time to time
based on the self-checking result. Although the diagnostic information is cleared before the L90 is shipped from the factory,
the user may want to clear the diagnostic information for themselves under certain circumstances. For example, it may be
desirable to clear diagnostic information after replacement of hardware. Once the diagnostic information is cleared, all self-
checking variables are reset to their initial state and diagnostics will restart from scratch.
PATH: COMMANDS PMU ONE-SHOT
COMMANDS
PMU ONE-SHOT
This feature allows pre-scheduling a PMU measurement at a specific point in time. This functionality can be used to test for
accuracy of the PMU, and for manual collection of synchronized measurements through the system, as explained below.
When enabled, the function continuously compares the present time with the pre-set
times match, the function compares the present sequence number of the measured synchrophasors with the pre-set
ONE-SHOT SEQUENCE NUMBER
the corresponding protocol data items for 30 seconds. This allows manual read-out of the synchrophasor values for the pre-
set time and pre-set sequence number (via the faceplate display, supported communication protocols such as Modbus or
DNP, and the EnerVista UR Setup software).
When freezing the actual values the function also asserts a
configured to drive an output contact and trigger an external measuring device such as a digital scope with the intent to ver-
ify the accuracy of the PMU under test.
With reference to the figure below, the PMU one-shot function (when enabled) controls three FlexLogic™ operands:
GE Multilin
PERFORM LAMPTEST?
No
UPDATE ORDER CODE?
No
SERVICE COMMAND:
0
UPDATING...
PLEASE WAIT
PMU ONE-SHOT
FUNCTION: Disabled
PMU ONE-SHOT
SEQUENCE NUMBER: 0
PMU ONE-SHOT TIME:
2005/06/14 7:58:35
. When the two numbers match, the function freezes the synchrophasor actual values and
L90 Line Current Differential System
Range: No, Yes
Range: No, Yes
Range: 0, 101

7.1.6 PHASOR MEASUREMENT UNIT ONE-SHOT

Range: Enabled, Disabled
Range: 0 to nominal frequency – 1 in steps of 1
Range: 24h time format
PMU ONE-SHOT TIME
FlexLogic™ operand. This operand may be
PMU ONE-SHOT OP
7.1 COMMANDS
7.1.5 RELAY MAINTENANCE
UPDATE
ORDER
. When the two
PMU
7-3
7