Wegner Crane CFW500 series Applications Manual - page 15
Introduction to the Crane
Crane | 15
NOTE!
The oversizing factor (1.15 or 1.30) is based on the standard acceleration ramps of the application
that are 3.0 seconds to accelerate and 2.0 seconds to decelerate. For smaller acceleration and
deceleration times may need to increase these factors.
Table 1.1 – Surrounding air temperature as CFW500 inverter frame
CFW500 Inverter Frame
Surrounding Air Temperature
Temperature (maximum) with
Derating
A, B, C D and E
-25 to 50 °C (-13 to 122 ºF)
60 °C (140 °F)
The braking resistor must be selected according to the equation:
Load
sistor
P
P
×
= 70
.
0
Re
with %ED = 100.0%
Being:
P
Resistor
= braking resistor power (kW);
P
Load
= power required by the load (kW).
%ED = braking duty cycle.
NOTE!
Refer to the CFW500 user's guide, table B.1, to verify the ohmic value of the braking resistor to be
used according to the frequency inverter model.
NOTE!
If the power required by the load is unknown use the motor rated power considering the service fact
to the dimensioning of the braking resistor.
1.5.2 Horizontal Motion
The inverter must be selected according to its rated normal duty current (I
Drive
):
Motor
Drive
I
I
×
= 00
.
1
Being:
I
Drive
= Frequency inverter rated current (A);
I
Motor
= motor rated current considering the service factor (A);
NOTE!
For temperatures higher than the specified as maximum (see table 1.1), limited to 10 °C above, the
oversizing factor (1.00) to determine the normal current (I
Drive
) must be increased by 0.02 per °C.
NOTE!
For altitude above 1000 m (3,300 ft) to 4000 m (13,200 ft), oversizing factor (1.00) to determine the
normal duty current (I
Drive
) must be increased by 0.01 to 100 m (330 ft) above 1000 m (3,300 ft).
The braking resistor must be selected according to the equation:
Load
sistor
P
P
×
=
40
.
0
Re
with %ED = 50.0%