Power Quality Analyzer Model 3945-B
33
4.1.5 Electrical Hookup (electrical network)
• Highlight ELECTRICAL HOOKUP with the
buttons, then press the
button.
The following screen will appear:
N
L1
Single-Phase
N
L1
L2
Two-Phase
N
L1
L2
L3
3 Phase 3-Wire
N
L1
L2
L3
3 Phase 4-Wire
07/25/02 10:26
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Figure 4-3
• Choose the hookup type with the
and
buttons.
• Press the
button to apply the new hookup selection.
Hookup Types:
Single or two-phase:
The neutral current is not measured or calculated.
3 phase-3 wire connection (3V, 3A):
On DELTA network:
Only power totals are measured.
Powers per phase are displayed, but not valid.
On WYE network: The neutral current is not calculated. It is necessary
to connect neutral (V) to obtain the power per phase.
3 phase-4 wire connection (4V, 3A):
The neutral current is available and
its value and waveform are displayed.
On WYE network: Powers per phase are available.
NOTE:
Neutral current is calculated, not measured, in the 4 wire hookup.
V1 must be connected in all hookups, since the display is synchronized from
V1 and the network frequency measured by V1.
Neutral current is calculated by adding, for each datapoint, each of the 3
measured phases of current. This assumes that all current flows through
neutral. This results in a 256 datapoint waveform. If the 3 phases of current
were balanced, the calculated neutral current would be 0 for every datapoint.