KEB COMBIVERT F5-A, Applications Manual, Page: 403 / 552

Protective functions
© KEB, 2012-10 COMBIVERT F5-A, -E, -H Page 7.13 - 29
7
Pn.14 specifies the performance of the drive on activation of the motor protective function.
Fig. 7.13.8.b tripping times
Tripping
time
f
≥ Rated motor frequency or
forced-ventilated motor
Motor current
50 100 150 200 400 600 800
%
5 sec
30 sec
1 min
2 min
30 min
60 min
120 min
120
f = 0 Hz
For self-ventilated motors the tripping times decrease with the frequency of the motor (see picture). The motor
protection function acts integrating, i.e. times with overload on the motor are added, times with underload are
subtracted.
After triggering the motor protection function, the new tripping time is reduced to 1/4 of the specified
value, if the motor has not been operated for an appropriate time with underload.
Motor protection function for F5-M
In some applications, several motors are operated alternatively at one inverter. The change-over between the
motors is done synchronously with the set changeover.
The motor protection function must then be able to distinguish which of the motors is currently being supplied.
For that purpose there is the parameter Fr.08 "motor set classification".
Each motor is assigned a number from
0 to maximally 7 and this value is entered in parameter Fr.08 in all sets where the respective motor is supplied.