39
DIRECTIONAL RELAY:
The DIRECTIONAL RELAY Test Screen is used to test all single-phase directional
overcurrent, ground directional overcurrent, or relays which have a directional
supervisory element which is sensitive to single-phase current and voltage. From the
TEST MENU
Screen, select
DIRECTIONAL RELAY
. The following test screen should
be displayed.
Many electro-mechanical relays with directional units do not have contacts that can be
easily monitored. Therefore, it is up to the operator to visually observe the directional
element contacts. For the relays, which have contacts that can be monitored, connect
these contacts to
STOP/MONITOR
gate.
Connect
AC CURRENT MAIN
to directional element current coil or input (note polarity).
Connect
DC AUX
output to relay (for solid state or microprocessor-based).
Connect
AC AUX
output terminals to the relay directional potential coil or input (note
polarity).
Note: If relay is solid state, or microprocessor-based, and requires a DC logic voltage
prior to applying test, connect the relay dc power terminals to the
DC AUX
terminals.
With the arrow key, highlight the
DC VOLTS
and press the
DC
Button. Increase the DC
voltage output by rotating the Control Knob until proper logic voltage is applied.
Directional Element Pick Up or “Sensitivity” Test:
1.
Using the arrow key, highlight the
AC VOLTS
. Press the
AC AUX
button to turn
the AC Volts on.
2.
Rotate Control Knob and increase AC Voltage output to the desired test voltage.
3.
Using the arrow key, highlight the
AC AMPERES
.
4. With
MODE SELECT
set to
MAINT.
(MAINTAIN), press the
INIT
button.
5.
Rotate Control Knob and increase current until the desired test current is set.
Note the phase angle displayed,
φ
I lags V
. The relay may be tripped at this
point depending on the measured phase angle displayed. The phase angle
display is the measured phase angle between the
AC CURRENT MAIN
output
Summary of Contents for SR-98
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