INSTALLATION AND CONNECTION
Where:
∆
V
- desired line drop, in percentage (%).
V
e
- phase voltage in the inverter input, in volts (V).
I
s,rat
- rated current of the inverter output.
f
- line frequency.
✓
NOTE!
WEG reactors available for CFW320 inverters are listed in the
3.2.3.3 Dynamic Braking
✓
NOTE!
The dynamic braking is available on DB models from frame size B onwards.
Refer to
for the following specifications of the dynamic braking: maximum current, minimum
braking resistance, rms current
(*)
and cable gauge.
(*)
The rms braking current can be calculated as follows:
I
ef f ective
=
I
max
·
√
t
br
(
min
)
5
Where:
t
br
- corresponds to the sum of the braking actuation times during the most severe cycle of five minutes.
The power of the brake resistor must be calculated considering the decelarion time, the inertia of the load and of
the resistive torque.
R
S
T
Contactor
Input power
supply
+BR
BR
Brake
resistor
Thermostat
Relay
Command
power supply
Figure 3.2:
Installation of brake resistor
Procedure to use the dynamic braking:
Connect the brake resistor between the power terBR and BR.
18 | CFW320
