BECKWITH ELECTRIC M-3425A, Instruction Book

Page: 346 / 482

6–59
Testing – 6
Pickup Test
:
1. Calculate the time for the pickup setting, then apply a sweep rate of 25% less than the Pickup (
P
)
to all three phases.
2. Press and hold the
TARGET RESET
pushbutton, then slowly decrease the sweep time until the
FREQUENCY/ROCOF 81/81R
LED illuminates, or the function status indicator on the
Monitor
Function Status
screen indicates that the function has picked up.
The level should be equal to
P

0.05 Hz/Sec. or

5 %.
3. Release the
TARGET RESET
pushbutton, then increase the sweep time. The
OUTPUT
LED will
extinguish.
Negative Sequence Voltage Inhibit Test
:
1. Press the
TARGET RESET
pushbutton to reset targets.
2. Apply
Nominal Voltage
to all three phases at a sweep rate 25% above
P
. The
Nominal Voltage
value previously input to the relay is described in Section 4.2, Setup System and should be recorded
on Figure A-2, Setup System Record Form.
Verify that the
FREQUENCY/ROCOF 81/81R
LED illuminates, or the function status indicator on
the
Monitor Function Status
screen indicates that the function has picked up.
3. Swing the phase angle of a Phase Voltage and monitor the Positive and Negative Sequence Voltage
levels. The
81R OUTPUT
should reset when the negative sequence voltage is
N
%,  0.5% of the
positive sequence voltage.
Timer Test
:
1. Press the
TARGET RESET
pushbutton to reset targets.
2. Apply
Nominal Voltage
to all three phases at a sweep rate 25% below
P
. The
Nominal Voltage
value previously input to the relay is described in Section 4.2, Setup System and should be recorded
on Figure A-2, Setup System Record Form.
3. Connect a timer to output contacts
(Z)
so that the timer stops timing when the contacts
(Z)
close.
4. Apply a sweep rate 25% above
P
and start timing. The contacts will close after
D
cycles within
+20 cycles.