Date Code 20020129
Testing and Troubleshooting
10-13
SEL-387E Instruction Manual
Table 10.1: Instantaneous Overcurrent Elements and Corresponding Settings
Winding 1
Winding 2
Winding 3
Bit Setting Bit Setting Bit Setting
Phase Level 1
50P11
50P11P
50P21
50P21P
50P31
50P31P
Phase Level 2
50P12
50P12P
50P22
50P22P
50P32
50P32P
Phase
Inverse-Time 51P1 51P1P
51P2 51P2P
51P3 51P3P
A-Phase
Level
3
50A13 50P13P 50A23 50P23P 50A33 50P33P
B-Phase
Level
3
50B13
50B23
50B33
C-Phase
Level
3
50C13
50C23
50C33
Phase Level 3
50P13
50P23
50P33
A-Phase
Level
4
50A14 50P14P 50A24 50P24P 50A34 50P34P
B-Phase
Level
4
50B14
50B24
50B34
C-Phase
Level
4
50C14
50C24
50C34
Phase Level 4
50P14
50P24
50P34
Residual
Level
1
50N11 50N11P
50N21 50N21P
50N31 50N31P
Residual
Level
2
50N12 50N12P
50N22 50N22P
50N32 50N32P
Residual
Inverse-Time
51N1 51N1P
51N2 51N2P
51N3 51N3P
Neg-Seq
Level
1
50Q11 50Q11P
50Q21 50Q21P
50Q31 50Q31P
Neg-Seq
Level
2
50Q12 50Q12P
50Q22 50Q22P
50Q32 50Q32P
Neg-Seq
Inverse-Time
51Q1 51Q1P
51Q2 51Q2P
51Q3 51Q3P
Definite-Time and Inverse-Time Overcurrent Elements
Note:
This example tests the Winding 1 51P1 phase inverse-time overcurrent element. Use the
same procedure to test all definite-time and inverse-time overcurrent elements for each
winding.
Step 1.
Purpose: Determine the expected time delay for the overcurrent element.
Method: 1. Execute
the
SHOWSET
command via the relay front panel or serial
port and verify the time delay settings (i.e.,
SHO 51P1<ENTER>
).
The delay settings will follow the pickup settings when they are
displayed.
2. Calculate the time delay to pickup (tp). Definite-time elements will
be equal to the delay setting (i.e., 50P11D setting for the 50P11
element). Inverse-time elements are calculated using three element
settings and the operating time equations shown in
Section 3:
Differential, Restricted Earth Fault, Overcurrent, Voltage, and
Frequency Elements
. TD is the time-dial setting (i.e., 51P1TD), and
M is the applied multiple of pickup current.