9171300990 Rev R
BE1-87T Setting Notes
A-1
APPENDIX A • SETTING NOTES
INTRODUCTION
These setting notes are to clarify several of the settings steps in Section 4,
Installation
.
SETTING NOTE 1
The procedure outlined in Step 1 assumes that
S
2
or
S
3
is zero and yields the correct magnitude and ratios.
This note is to point out that the relay taps are determined by the windings turn ratios. The use of the MVA
rating is only a convenient way of calculating the currents (i.e. taps) in proportion to their voltage rating. It
does not mean that the windings will necessarily carry the maximum rating.
S
V I
2
2
2
3
=
S
V I
3
3 3
3
=
S
V I
1
1 1
3
=
V
2
V
3
V
1
I
3
I
2
I
1
D2751-16
01-30-98
S
S
S
V I
V I
V I
I
V
V
I
V
V
I
S
V
1
2
3
1 1
2
2
3 3
1
2
1
2
3
1
3
1
1
3
=
+
=
× +
×
=
=
+
S = Winding Rating (MVA)
Figure A-1. Multi-winding Transformer
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