CT Lab Vecto III, User Manual

Page: 34 / 80

Vecto III User Manual
34
2.4.4 Voltage Inputs
The Vecto III has 4 resistive differential voltage inputs made up of 6 terminals.
The first 4 terminals are used for 3 voltage inputs. V
1
, V
2
and V
3
are Neutral (V
com
)
referenced (V
1
-N, V
2
-N, V
3
-N).
The last 2 terminals are used for the 4
th
(V
4+
, V
4-
) voltage input. It is a full differential
measurement normally used for Neutral to Earth measurement.
The voltage inputs make use of a 6-terminal lockable connector plug. Each terminal
can accommodate conductors with sizes up to 2.5 mm
2
. Figure 9 shows the voltage
connections for a 3-phase 4-wire star system. Power is calculated per phase and
arithmetically added to obtain the 3-phase powers.
Figure 10 shows the voltage connections for a 3-phase 3-wire delta connection. Three-
phase power is calculated by the 2-watt meter method.
If voltages are connected in star (4-wire) on the terminals the
user can select star (4-wire) or delta (3-wire) topology in the
software