Faults And Alarms; Motor Overload Protection (F0072 And A0046) - WEG CFW501 V1.8X Programming Manual

Faults and Alarms

14 FAULTS AND ALARMS
The problem detection structure in the inverter is based on the fault and alarm indication.
In case of fault, the IGBTs will be locked and the motor will stop by inertia.
The alarm works as a warning for the user that critical operating conditions are taking place and that a fault may
occur if the situation is not corrected.
Refer to chapter 6 - Troubleshooting and Maintenance of the CFW501 user's manual and QUICK REFERENCE
OF PARAMETERS, ALARMS AND FAULTS on page 0-1 contained in this manual to obtain more information
regarding the faults and alarms.

14.1 MOTOR OVERLOAD PROTECTION (F0072 AND A0046)

The motor overload protection is based on the use of curves that simulate the heating and cooling of the motor
in cases of overload. The motor overload protection fault and alarm codes are F0072 and A0046 respectively.
The motor overload is given considering the reference value In x FS (motor rated current multiplied by the duty
factor), which is the maximum value at which the overload protection must not actuate, because the motor can
work continuously at that value without damages.
However, for that protection to actuate properly, the winding-temperature supervision (which corresponds to the
time of heating and cooling of the motor) is estimated.
This thermal image is approximate by means of a function called Ixt, which integrates the output current value
from a level previously defined by P0156, P0157 and P0158. When the accumulated value reaches the limit, an
alarm and/or fault are indicated.
In order to ensure greater protection in case of restart, this function keeps the value integrated by the function
lxt in the inverter non-volatile memory. Thus, after the energizing, the function will use the Ixt value saved in this
memory to perform a new evaluation of overload.
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