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1MRK 505 288-UEN A
Technical manual
Set value for
Formula used for complex, three-
parameter
phase power calculation
"Mode"
4
L1L2
=
S
U
EQUATION1391 V1 EN
5
L2L3
=
S
U
EQUATION1393 V1 EN
6
L3L1
=
S
U
EQUATION1395 V1 EN
7
L1
= ×
S
3
EQUATION1397 V1 EN
8
L2
= ×
S
3
EQUATION1399 V1 EN
9
L3
= ×
S
3
EQUATION1401 V1 EN
* means complex conjugated value
It shall be noted that only in the first two operating modes that is, 1 & 2 the
measurement function calculates exact three-phase power. In other operating modes
that is, from 3 to 9 it calculates the three-phase power under assumption that the power
system is fully symmetrical. Once the complex apparent power is calculated then the
P, Q, S, & PF are calculated in accordance with the following formulas:
=
P
Re( )
S
EQUATION1403 V1 EN
=
Q
Im( )
S
EQUATION1404 V1 EN
Formula used for voltage and
current magnitude calculation
×
-
*
*
U
(
I
I
)
L L
1 2
L
1
L
2
(Equation 36)
I
EQUATION1392 V1 EN
×
*
-
*
U
(
I
I
)
L L
2 3
L
2
L
3
(Equation 38)
I
EQUATION1394 V1 EN
×
*
-
*
U
(
I
I
)
L L
3 1
L
3
L
1
(Equation 40)
I
EQUATION1396 V1 EN
×
*
U
U
I
L
1
L
1
(Equation 42)
I
EQUATION1398 V1 EN
×
*
U
U
I
L
2
L
2
(Equation 44)
I
EQUATION1400 V1 EN
×
*
U
U
I
L
3
L
3
(Equation 46)
I
EQUATION1402 V1 EN
Section 12
Monitoring
Comment
Used when
=
U
only U
L L
1 2
phase-to-
=
+
phase
(
I
I
) / 2
L
1
L
2
voltage is
available
(Equation 37)
Used when
=
U
only U
L L
2 3
phase-to-
=
+
phase
(
I
I
) / 2
L
2
L
3
voltage is
available
(Equation 39)
Used when
=
U
only U
L L
3 1
phase-to-
=
+
phase
(
I
I
) / 2
L
3
L
1
voltage is
available
(Equation 41)
Used when
=
×
3
U
only U
L
1
phase-to-
earth voltage
=
I
is available
L
1
(Equation 43)
Used when
=
×
3
U
only U
L
2
phase-to-
earth voltage
=
I
is available
L
2
(Equation 45)
Used when
=
×
3
U
only U
L
3
phase-to-
earth voltage
=
I
is available
L
3
(Equation 47)
L1L2
L2L3
L3L1
L1
L2
L3
(Equation 48)
(Equation 49)
335
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