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, expressed as
impedance drop in percent are following:
a) For the model with rated current
130 A/220-230 V,
142 A/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
44 A/500-600 V or
107 A/500-690 V or
100 A/660-690 V: there is no requirement for the minimum required line
impedance for the CFW-09 protection. 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
supply transformer 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
The Line Reactor and the DC Bus Choke, when properly sized, 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 supply voltage transients.
DC Link Inductor equivalent to the line reactor is:
