ZES ZIMMER LMG450, Руководство пользователя

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Installation LMG450
40
3.3.3 Measuring circuit (typical) for star to delta conversion (option L45-O6)
L 1
G ro up A
M o tor
L 2
L 3
P E
Figure 5: Star to delta conversion
With group A you measure the linked voltages and the currents in the phases. The LMG450
calculates with this both values a power for each channel, but this power will not be the power
of the system, because the measured voltages (U
12
, U
23
and U
31
) belong not to the currents (I
1
,
I
2
and I
3
). The power values are a mix from star and delta values.
But with the star to delta conversion, you can either transform the voltages to star voltages or
you can transform the currents to delta currents. This will depend on your load. Now you have
voltage and current in the same circuit and now you have also power values which exist in
your circuit.
However the group B can be used independently like in the above examples.
This circuit should be measured with wiring ‘3+1, U
∆
I*->U
∆
I
∆
’ or ‘3+1, U
∆
I*->U*I*’.