6-4
IM WT3001E-51EN
• Star>Delta
Computes various data of a delta connection from the data of a star connection (star-
delta transformation) using the data from a three-phase, four-wire system.
∆F1[UrsA]
∆F2[UstA]
∆F3[UtrA]
∆F4[InA]
I
I
R
S
T
U
U
U
I
N
I1
I2
I3
U1
U2
U3
UrsA
UtrA
UstA
InA
• Delta>Star
Computes various data of a star connection from the data of a delta connection (delta-
star transformation) using the data from a three-voltage, three-current system. The
neutral point of the star connection is computed as a centroid of the delta connection.
If the actual neutral point does not match the centroid, an error results.
∆F1[UrA]
∆F2[UsA]
∆F3[UtA]
∆F4[InA]
I
I
R
S
T
U
U
U
I
N
I1
I2
I3
U3
U2
U1
UrA
UtA
UsA
InA
Note
• It is recommended that the measurement range and scaling (VT/CT ratio and
coefficients) of the elements that are being computed (delta computation) be set
the same as much as possible. Using a different measurement range or scaling
causes the measurement resolution of the sampled data to be different. In effect,
the computation result will have errors.
• The number (1, 2, 3, and 4) that is attached to the measurement function symbol of
the delta computation has no relation to the element number. The computation of
the measurement functions ∆F1 to ∆F4 of delta computation varies depending on
the wiring system and the delta computation type. For details, see section 6.3.
• On models with a single element, this function does not work Therefore, the setup
menus do not appear.
• If the target wiring system for delta computation is a single-phase, two-wire system
(1P2W), delta computation cannot be performed.
6.2 Setting the Delta Computation