Load Reactor; Rheostatic Braking - WEG CFW-10 EASYDRIVE User Manual

CHAPTER 8 - OPTIONS AND ACCESSORIES
8.3

LOAD REACTOR

8.4

RHEOSTATIC BRAKING

86
As an alternative criterion, we recommend to add a line
reactor always the transformer that supplies the inverter has
rated output higher than indicated in table below:
Inverter Model
1,6A and 2,6A/200-240V
4A/200-240V
1,6A, 2,6A and 4,0A/
110-127V
7,3A/220-240V
Note: The value for the rated apparent power can be obtained in section 9.1 of this
manual.
Table 8.2 - Alternative criteria for use of line reactor -
Maximum values of the transformer power
The use of a three-phase load reactor, with an approximate
2% voltage drop, adds an inductance at the inverter output to
the motor. This decreases the dV/dt (voltage rising rate) of
the pulses generated at the inverter output. This practice
reduces the voltage spikes on the motor windings and the
leakage currents that may be generated when long cables
between inverter and motor (as a function of the "transmission
line" effect) are used.
WEG Motor with voltages up to 460V, no use of load reactor
is required, since the insulation of the motor wires support
the operation bi the CFW-10. If the cables between inverter
and motor are longer than 100m (300ft), the cable capacitance
to ground increases. In this case it is also recommended to
use a load reactor.
PE
Q1
L/L1
N/L2
LINE
Figure 8.3 - Load Reactor Connection
The rheostatic braking is used when short deceleration times
are required or when high inertia loads are driven.
For the correct braking resistor sizing the following application
data shall be considered: deceleration time, load inertia,
braking duty cycle, etc.
Power of the Transformer [kVA]
30 x rated apparent power of the inverter [kVA]
6 x rated apparent power of the inverter [kVA]
6 x rated apparent power of the inverter [kVA]
10 x rated apparent power of the inverter [kVA]
L/L1 N/L2 U V W PE
LOAD
REACTOR
PE W V U
SHIELD