Sizing - WEG CFW-10 EASYDRIVE User Manual

8.4.1 Sizing

V
Máx
(Maximum
CFW-10
Resistor
Model
Voltage)
1,6A/200-240V
2,6A/200-240V
4,0A/200-240V
7,3A/200-240V 410 V
1,6A/110-127V
2,6A/110-127V
4,0A/110-127V 460V
CHAPTER 8 - OPTIONS AND ACCESSORIES
In any case, the RMS current capacity and the maximum peak
current shall be respected.
The maximum peak current defines the minimum resistance
value (ohms) of the braking resistor. Refer to table 8.3.
The DC Link voltage level at which the rheostatic braking is
activated is the following:
- CFW-10 200-240V models – 366V DC
- CFW-10 110-127V models – 411V DC
The braking torque that can be achieved through the
application of frequency inverters, without using the rheostatic
braking module, varies from 10% to 35% of the motor rated
torque.
During the deceleration, the kinetic energy of the load is
regenerated to the DC Link (intermediary circuitry). This
regenerated energy charges the capacitors at the intermediary
circuitry increasing the voltage level at the DC Link. In case
this additional energy is not dissipated, an overvoltage error
(E01) may occur disabling the inverter.
In order to have higher braking torques the rheostatic braking
is applied. When using the rheostatic braking, the additional
regenerated energy is dissipated in an external resistor. The
braking resistor power is a function of the deceleration time,
the load inertia and the resistive torque.
Use WIRE or RIBBON resistors in ceramic case with
appropriated insulation voltage to withstand a high
instantaneous power (respecting to the rated power).
Maximum
P
max
Bracking (Resistor
Current
Peak
Power)
11 A
4,3 kW
12A 5,4 kW
Table 8.3 - Recommended braking resistors
NOTE!
Data presented in table 8.3 were calculated for the maximum
power admissible for the frequency converter. For smaller
braking power, another resistor can be used according to the
application.
Maximum P
rms
Recommended
RMS (Resistor
Bracking Maximum
Current Power)
Braking not available
10 A 3,9 kW
Braking not available
5 A 2,2 kW
Recommended
Resistor
Wiring
39 Ω
2,5 mm 2 / 14 AWG
39 Ω
2
2,5 mm / 14 AWG
87