![Schweitzer Engineering Laboratories SEL-387E Скачать руководство пользователя страница 401](http://html1.mh-extra.com/html/schweitzer-engineering-laboratories/sel-387e/sel-387e_instruction-manual_1216724401.webp)
Date Code 20020129
Testing and Troubleshooting
10-27
SEL-387E Instruction Manual
Step 3.
Purpose: Select a test point on the percentage differential curve in Figure 10.7.
Method: Decide where you want to cross the differential characteristic by picking a
restraint value IRT, which is a vertical line on the graph. Since this test is
for the SLP2 threshold, select a point above the IRS1 setting.
IRT
> IRS1
The value of IOP that corresponds to the selected IRT is as follows:
ÜÜÝ
Û
ÌÌÍ
Ë
-
+
=
100
2
SLP
1
SLP
•
1
IRS
IRT
•
100
2
SLP
IOP
Both IRT and IOP are in multiples of tap.
Step 4.
Purpose: Calculate the expected current for Winding 1 and 2 at the restrained
differential element SLP2 threshold for the test point selected above.
Method: Calculate the Winding 1 current for the test using the following formula:
A
•
1
TAP
•
200
2
SLP
1
SLP
•
1
IRS
200
2
SLP
1
•
IRT
1
IAW
Ü
Ü
Ý
Û
Ì
Ì
Í
Ë
ÜÜÝ
Û
ÌÌÍ
Ë
-
+
ÜÜÝ
Û
ÌÌÍ
Ë
+
=
Calculate the Winding 2 current for the test using the following formula:
A
•
2
TAP
•
200
2
SLP
1
SLP
•
1
IRS
200
2
SLP
1
•
IRT
2
IAW
Ü
Ü
Ý
Û
Ì
Ì
Í
Ë
ÜÜÝ
Û
ÌÌÍ
Ë
-
-
ÜÜÝ
Û
ÌÌÍ
Ë
-
=
The A connection compensation constant is based on Table 10.3. Because
the windings have the same WnCTC setting, the A constant will be the
same for both windings. The A constant must be used to achieve the
exact curve point on which we have based the calculations. The TAPn
settings can be different for the two windings.
&$87,21
The continuous rating of the current inputs is 3
•
I
nom
. If any currents in
this test will exceed this rating, reduce the TAPn values as needed, to
prevent possible damage to the input circuits.
Step 5.
Purpose: Calculate the initial current for Winding 2 for this test.
Method: Calculate the Winding 2 initial current by multiplying the Winding 2
expected current calculated above by 110 percent.
IAW2 (initial) = 1.1•IAW2 (from Step 4)
Содержание SEL-387E
Страница 8: ......
Страница 10: ......
Страница 12: ......
Страница 50: ......
Страница 124: ......
Страница 176: ......
Страница 196: ......
Страница 198: ......
Страница 242: ......
Страница 270: ......
Страница 308: ......
Страница 422: ......
Страница 428: ......
Страница 432: ......
Страница 448: ......
Страница 450: ......
Страница 462: ......