KEB COMBIVERT F5-A, Applications Manual, Page: 380 / 552

Page 7.13 - 6 COMBIVERT F5-A, -E, -H © KEB, 2012-10
Protective functions
7.13.1.2 Overvoltage
"Error! Overvoltage" is triggered if the DC link voltage increases beyond the overvoltage level due to energy
recovery in regenerative operation.
7.13.1.3 overcurrent
The "Error! Overcurrent" (E.OC) is trigger when the "OC-tripping current" (see technical data in the instruction
manual power circuit F5) is exceeded.
If this error occurs permanently, either the connected motor (short circuit or ground fault) or the inverter itself
is defective.
The "maximum short time current limit" is below the overcurrent limit. If it is exceeded, the hardware current
limit can be triggered with uF.15. The response of this function is not considered an error or malfunction, and
the corresponding switching conditions are not set. If the function is active, the status "80:hardware current
limitation active" (HCL) is displayed.
For current regulated drives, this function should be deactivated since it may have negative effects for the motor
model calculation and the behaviour of the drive.
7.13.1.4 overload
The inverter-overload protection is a function that triggers an error for which, however, a pre-warning can be
generated.
There are two overload protection functions: one for the range of standstill and low frequencies (overload at
standstill/ OL2) and one for the remaining frequency range (overload/ OL).
With Pn.09 "Overload warning level" a value between 0...100 % can be adjusted, when the "Warning! Overload"
or the "Warning! Overload during standstill", is set. The response to the overload warning is set with Pn.08
"warning OL stop. mode".
Overload in the standstill (OL2)
The implementation of the function "19: Overload during standstill" is described in chapter 2.1.9 "Overload
protection in the lower speed range". The motor current is guided via a PT1 link with a time constant of 280 ms.
If this delayed current exceeds the OL2 limit, "Error! Overload during standstill" (E.OL2) is triggered. If the dela-
yed current decreases to 0 again, the inverter enters the status "20: Overload during standstill fixed" (E.nOL2).
The error can now be reset.
Overload (OL)
The implementation of the general overload protection is described in chapter 2.1.8 "Overload characteristics".
If the 100% load factor of the inverter is exceeded by 5 %, the internal overload counter starts to count forward.
If the load factor falls below 100 %, the counter counts backward. The current counter content can be read in
parameter ru.39. Upon reaching 100 % the inverter switches off with error message "E.OL" and the counter
counts backward. If it reaches 0 %, the status changes to E.nOL and the error can be reset.