Advertisement
Power Automation and Protection Division
3.3.
Key Switches
The front panel contains 7 keys:
• Display Select
• Target Acknowledge
• Function Raise
• Function Lower
• Value Raise
• Value Lower
• Enter (recessed for security purposes)
The "Display Select" key is used to select one of the five (5) display modes, which is indicated
when the proper LED illuminates. When a fault is detected, the "LAST FAULT" flashes once per
second. If two faults are recorded, the "LAST FAULT" flashes twice per second, and the prior
fault will be moved from "LAST FAULT" to "PREVIOUS FAULT". The new fault data will be
stored in the "LAST FAULT" register. By depressing the "Target Acknowledge" key, the flashing
LED indicators are cleared, and the LED will revert back to the Metering mode. The information
in the "PREVIOUS FAULT" and "LAST FAULT" will not be reset from the front panel key switch,
but will be reset from External Reset (TB5-7 and TB5-8) and the remote reset through the Com-
munication Interface.
The "Function Raise" and "Function Lower" keys are used to scroll thru the information for the
selected display mode. The "Value Raise" and "Value Lower" keys are used to scroll thru the
different values available for each of the five functions. The "Enter" key is used to enter (in mem-
ory) a new value for settings.
4.
FRONT PANEL OPERATION
The front (operator) panel provides a convenient means of checking or changing settings, and
for checking relay unit operations after a fault. Information on fault location, trip types, phase,
operating units, and breakers which tripped become available by using the keys to step thru the
information. Targets (fault data) from the last two faults are retained, even if the relay is deen-
ergized. The operator is notified that targets are available by red flashing LEDs on the front pan-
el; in addition, alarm output-relay contacts are provided for the external annunciators.
The operator can identify nonfault voltage, current and phase angle on the front panel display.
Settings can be checked easily, however, any change to the settings requires the use of the
keys. When relay is in the normal operating mode, it is good practice to set the LED on the
Volts/Amps/Angle mode.
4.1.
Settings Mode
In order to determine the REL 352 settings that have been entered into the system, continually
depress the "DISPLAY SELECT" key until the "SETTINGS" LED is illuminated. Then depress
the "FUNCTION RAISE" or "FUNCTION LOWER" key, in order to scroll thru the REL 352 SET-
TINGS functions (
RAISE" or "VALUE LOWER" key in order to scroll thru the REL 352 values available for the par-
ticular function. (Each value that appears, as each different function appears in the function
field, is considered to be the "current value" used for that particular function.)
REL 352 Version 1.00
). For each settings function displayed, depress the "VALUE
see Table 4-3
I.L. 40-201.9
4
4-3
Advertisement
