ZES ZIMMER LMG450, User Manual

Page: 38 / 306

Installation LMG450
38
The following diagrams are some examples for typical connections of the LMG450. But all
other measuring circuits are also possible (e.g. circuits which measure the correct current
instead of the correct voltage).
3.3.1 Measuring circuit for typical line applications using the internal current
path
L 1
LO
A
D L 2
L 3
N
P E
Figure 3: Measuring circuit 3 phase system with neutral
In this circuit we measure with the first three channels the voltage, current and power of the
three phase system. With the fourth channel we measure additionally the current in the neutral
wire and the voltage between neutral and earth. Of course you can use the same circuit without
the fourth channel, if you are not interested in this values.
This circuit should be measured with wiring ‘3+1 Channels’.
Wiring ‘4+0 Channels’ is also possible, but then the measured power of channel 4 would be
added to the total power of the system (this could be correct, but depends very much on what
you want to measure!).