WEG CFW-09 - Application Criteria

264
CHAPTER 7 - DIAGNOSTICS AND TROUBLESHOOTING
The line reactor or the
DC Link Inductor
shall be applied when required
impedance is insufficient for limiting the input current peaks, thus preventing
damages to the CFW-09. The minimum required impedances, expressedas
impedance drop in percent are following:
a)
For the model with rated current

130A/220-230 V,

142A/380-480 V or

32 A/500-600 V: drop of 1 % for the line voltage;
b)
For the model with rated current

180 A/380-480 V : drop of 2 % for the
line voltage;
c)
For models with rated current

44A/500-600 V or

107A/500-690 V or

100 A/660-690 V: there is no requirement for the minimum required line
impedancefor theCFW-09protection.These impedances are ensured by
the internal existing DC choke. The same is applicable when DC Link
inductor is incorporated into the product (Special Hardware - Code HC or
HV), in the models with currents

16 A/220-230 V or

13 A/380-480 V
and

240 A/380-480 V.
As an
alternative criteria
, a line reactor should be added when the
inverter
supplytransformer has a rated power higher than indicated below:
8.7.1 Application Criteria
L
=
Voltage Drop [%] x Line Voltage [V]
3 x 2

Line Freq [
Hz
] x Rated Cur.[A]
[H]
To determine the line reactor needed to obtain the desired voltage drop,
use equation below:
Transformer
Power [kVA]
125
5 X Inverter Rated Power
2 X Inverter Rated Power
CFW-09 Rated Current/
volts
6 A to 28 A/220-230 V
3.6 A to 24 A/380-480 V
2.9 A to 14 A/500-600 V
45 A to 130 A/220-230 V
30 A to 142 A/380-480 V
22 A to 32 A/500-600 V
180 A to 600 A/380-480 V
Table 8.10
- Line reactor usage criteria
NOTE!
The 44 A to 79 A/500-600 V, 107 A to 472 A/500-690 V and 100 A to 428 A/
660-690 V models have a DC Link inductor built in the standard version. It is
not necessary to have minimum supply impedance or add external line
inductors for protecting these models.
L
DC
-
EQUIVALENT
= L
AC
X
3
TheLineReactorand the DCBus Choke,whenproperlysized, have practically
the same efficiency in reducing the harmonic currents. The DC Bus Choke
has the advantage of not introducing a motor voltage drop, while the Line
Reactor is more efficient to attenuate power supplyvoltage transients.
DC Link Inductor equivalent to the line reactor is: