WEG CFW300 V1.3X, Programming Manual

Page: 119 / 157

Faults and Alarms
CFW300 | 14-1
14
14 FAULTS AND ALARMS
The problem detection structure in the inverter is based on the fault and alarm indication.
In case of fault, the locking the IGBTs and motor stop by inertia will occur.
The alarm works as a warning for the user of critical operating conditions and that may cause a fault if the situation
is not corrected.
Refer to chapter 6 of the CFW300 user's manual and the QUICK REFERENCE OF PARAMETERS, ALARMS AND
FAULTS on page 0-1 of this manual to obtain more information regarding Faults and Alarms.
14.1 MOTOR OVERLOAD PROTECTION (F072 AND A046)
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 F072 and A046 respectively.
The motor overload is given considering the reference value In x SF (motor rated current multiplied by the service
factor), which is the maximum value at which the overload protection must not actuate, because the motor can
work continuously at that current 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 winding-temperature supervision is approximated by a function called Ixt, which integrates the output current
value from a level previously defined by P156, P157 and P158. When the accumulated value reaches the limit, an
alarm and/or fault are indicated.
P156 - Overload Current at Rated Speed
P157 - Overload Current 50 % of Rated Speed
P158 - Overload Current 20 % of Rated Speed
Adjustable
Range:
0.1 to 2 x I
nom
Factory
Setting:
1.2 x I
nom
Properties:
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.
In order to deactivate the motor overload function, just set parameter P156 to P158 to values equal to or above
twice the inverter rated current P295.