Basler Electric BE1-87T User Manual
Page 99
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9171300990 Rev V
BE1-87T Test Procedures
5-3
Example One:
Assume:
tap
tap
slope
1
2
2
38
15%
=
=
=
,
. ,
Inputs I
A pu
I
T
pu
I
A pu
I
T
pu
:
(
)
.
(
)
.
.
1
1
1
2
2
2
2
1
2
2
1
38 1
38
38
1
=
=
=
=
=
=
Check:
Therefore: Use Equation 2 or 2a.
From Figure 1-2 (the percentage restraint characteristic of the BE1-87T at 15% slope), the minimum
current where trip occurs is:
In terms of current, the trip current is:
Using Equation 2a:
I
trip
1
2 38
38
0 35
2 7
=
+
=
.
.
.
. A
Example Two:
Assume:
tap
tap
slope
1
2
2
38
15%
=
=
=
,
. ,
Inputs I
A
pu
I
T
pu
I
A
pu
I
T
pu
:
(
)
.
(
)
.
.
1
1
1
2
2
2
6
3
6
2
3
114
3
114
38
3
=
=
=
=
=
=
I balance
slope
slope
1
0.35
100
1
100
< >
−
(in pu)
<
1 1.983
(
)
(
)
1 < >
0.35
0.15
1 - 0.15
(
)
I
trip
1
= 1 pu + 0.35
= 1.35 pu
I
tap
trip
1
(2 0)
2 70
=
x
=
±
±
1.35 pu
= (1.35)
A 6% 100 mA
.
.
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