WEG Drive Scan, Manual

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8
DRIVE SPECIALIST
b) Electrical protection devices connected to the inverter input, such as overload relays and fuses, may
trip due to higher values of current peaks and effective currents in the AC power supply and greater
voltage imbalance(
Figure 8.6 ).
0 10 20 30 40 50 60 70 80 90 100
Potência de saída (%)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
Amp
litud
e
d
e
te
nsã
o
120H
z
CC
(V)
Componente de harmônica 120Hz para diferentes níveis de desbalancemento de tensão
0%
1%
2%
3%
4%
5%
6%
Crítico
Alerta
F006 - Desequilíbrio
Falta de Fase na Rede
Critical
Error
120Hz harmonic for different voltage imbalance levels
F006 - Imbalance
Phase Fault
Output power (%)
120Hz Harm
onic (V)
Figure 8.5: Indications of power quality in relation to the AC power supply phase balance - examples for 60 Hz power supply
Figure 8.6: Current waveforms
I
R
,
I
S
and
I
T
in the AC power supply as a function of the imbalance of the power supply phases - examples
for 60 Hz supply
The values of currents I
R
, I
S
e I
T
in the AC power supply as a function of the imbalances of power
supply phases can be seen in Table 8.3 .
Low Voltage Devices | 8-4