WEG CFW100 Programming Manual page 112

For example, for a constant ratio with 150 % of overload, Fault F072 occurs in 60 seconds. On the other hand, for
output current values below P156, P157 or P158 according to the output frequency, fault F0072 does not occur.
For ratio values above 150 % the fault actuation time is below 60 s.
3
2,5
2
1,5
1
0,5
0
0
✓
NOTE!
In order to ensure greater protection in case of de-energization of the inverter, this function keeps the
information regarding the motor thermal image in a non-volatile memory area of the inverter. Thus,
after the inverter energization, the function will use the saved value of the thermal image to execute a
new overload assessment.
P156 - Rated Speed Overload Current
P157 - Overl.Curr.50 % Speed
P158 - Overl.Curr.20 % Speed
Range: 0.1 to 40.0 A
Description:
These parameters define the motor overload current (Ixt - F072). The motor overload current is the current value
(P156, P157 or P158) based on which the inverter will understand that the motor is operating in overload.
For self-ventilated motors, the overload current depends on the speed at which the motor is spinning. Therefore,
for speeds below 20 % of the rated speed, the overload current is P158, while for speeds between 20 % and 50
% the overload current is P157, and above 50 % it is P156.
The greater the difference between the motor current and the overload current (P156, P157 or P158) the faster the
actuation of fault F072.
It is recommended that parameter P156 (motor overload current at rated speed) be set at a value 10 % above the
used motor rated current (P401).
Region of overload
60 120
Time (s)
Figure 10.2: Actuation of the motor overload
FAULTS AND ALARMS
180 240
Micro Mini Drives | 10-5
300
10