Date Code 20080110 Testing and Troubleshooting 10-41
SEL-387E Instruction Manual
Step 22.
Purpose: Display the appropriate Relay Word bit on the front-panel LEDs.
Method: Execute the
TARGET
command (i.e.,
TAR F 24C2T <Enter>
). The
SEL-387E Relay now displays the state of the volts/hertz elements on the
bottom row of front-panel LEDs.
Step 23.
Purpose: Apply balanced three-phase voltage and change the voltage until the
appropriate LED illuminates.
Method: Apply balanced three-phase voltages as shown in
Figure 10.5. Change the
voltage to a value above the
24IP
setting until the
24C2T
LED
illuminates. Refer to
Section 3: Protection Functions
for the maximum
inverse-time timing error. Calculate pickup time as:
IC24
1
%100
IP24
10•V
NFREQ
•
freq
PTR•V•3
ITD24
T2C24
3
nom
sec
⎟
⎟
⎟
⎟
⎟
⎟
⎠
⎞
⎜
⎜
⎜
⎜
⎜
⎜
⎝
⎛
−
=
V
sec
= Secondary voltage (applied)
PTR = Potential transformer ratio (Setting)
Freq = Frequency (applied)
NFREQ = Nominal Frequency (Setting)
V
nom
= Nominal Voltage in kV (Setting)
24ITD = Inverse time factor (Setting)
24IP = Inverse time pickup (Setting)
24IC = Inverse time curve (Setting)
Step 24.
Purpose: Verify the Level 2 volts/hertz delay reset setting.
Method: Execute the
SHOWSET
command via the relay front panel or serial port
and verify the setting (i.e.,
SHO 24CR <Enter>
).
Step 25.
Purpose: Display the appropriate Relay Word bit on the front-panel LEDs.
Method: Execute the
TARGET
command (i.e.,
TAR F 24CR <Enter>
). The
SEL-387E Relay now displays the state of the volts/hertz elements on the
bottom row of front-panel LEDs.
To Next Page
Loading...
