I I I I I Common characteristics of power measurements
The active and reactive power measurements are signed, whereas the apparent power
measurement is not.
The display indicates "OL" if the voltage or current is in "OL".
3.4.1
Specific reference conditions
DC: AC component < 0.1% of the DC signal
AC: - Sinusoidal signals
- PF = 1
- Frequency: 50 Hz
3.4.2
Active power measurements
1. Press the ON/OFF key: the first screen appears
2. Connect the measurement leads to the instrument's current measurement terminals
(on the left), complying with the polarities indicated: red lead on the "+" terminal and
black lead on the "COM" terminal.
Connect the measurement leads to the instrument's voltage measurement terminals
(on the right), complying with the polarities indicated: red lead on the "+" terminal
and black lead on the "COM" terminal.
Set up as indicated in the connection diagrams in Fig.4.4.1 (single phase) or Fig.4.4.2
(balanced three-phase, T3FE only PX 120), depending on the case, making sure if
possible that the maximum acceptable limits are not exceeded (see table below).
Range switching is automatic.
I I I I I Single-phase characteristics
Display range
Measuring range
Accuracy at 50Hz for PF ≥ 0.8 1.5% of reading ±2 cts 1.5% of reading ±2 cts
Accuracy with DC
Resolution
I I I I I Three-phase characteristics
Display range
Specified measuring range
Accuracy at 50Hz for PF ≥ 0.8
Resolution
Note: With three-phase, the measurement of the active power is only performed on
the fundamental components, so it is only valid for sinusoidal signals.
Wattmeters
I
L 1
Alimentation
Power supply
U
L 2
L 3
Fig 4.4.2 Three-phase/balanced wires (T3FE)
connection diagram (PX 120 only)
10.00 W...999.9 W
2.5%of reading ±5 cts
10.00 W - 999,9 W
3% of reading ±2 cts
I+
W
C h a r g e
Load
U+
1000 W
1000 W...5999 kW
2.5%of reading ±5cts
0.1W
1000 W
1000 W – 5999 W
3% of reading ±2 cts
0.1W
Chapter III
L 1
L 2
L 3
6 kW
1 W
6 kW
1 W
29