KEB COMBIVERT F5-A, Applications Manual, Page: 385 / 552

Protective functions
© KEB, 2012-10 COMBIVERT F5-A, -E, -H Page 7.13 - 11
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7.13.1.13 Speed limit exceeded
The status "58: ERROR! Overspeed“ (E.OS) is triggered, if ru.07 "actual value display" exceeds either the va-
lue of oP.40 / oP.41 "max. output val." or the value of ru.79 „abs. speed EMC“ (only for synchronous motors).
With oP.40 / oP.
41, the user defines limits that may not be exceeded by the application under any circum
-
stances.
ru.79 shows the maximum speed for a synchronous motor which, if exceeded, leads to an EMC of the motor
high enough to damage the DC-intermediate circuit of the inverter.
Reason for the occurence of excessive speed can be too small a distance between the maximum setpoint and
the speed limit, so that overshoots can trigger the error. Other causes can be (e.g., caused by EMC) malfunc-
tions in the speed measurement or a noisy, insufficiently smoothed speed estimate in the encoderless control
(SCL or ASCL).
7.13.1.14 Speed controller limit reached
Pn.75 "response to error E.SCL" determines how the output should respond if the speed controller reaches the
limit, i.e., if the set torque reaches the maximum possible value. In the factory setting, this operating condition
can be applied to a digital output (switching condition "53: Speed control at the limit"). With Pn.75, however, it is
also possible to execute an abnormal stopping on reaching the torque limit (Status "107: ABN. Speed controller
limit"/ A.SCL) or to trigger an error (Status "25: ERROR! speed controller limit“ / E.SCL)
7.13.1.15 Maximum acceleration exceeded
The maximum permissible acceleration is defined with Pn.79 "Acceleration limit 1/s^2".
Pn.80 "Acceleration scan time" determines the time period used for acceleration averaging.
The change of the actual speed (ru.07) in this time period, divided by the scan time (Pn.80) is the actual acce-
leration. The speed difference must be converted from 1/min to 1/s for the calculation of the acceleration.
Speed change during scan time
—————————————————————
60 x acceleration scan time (in seconds)
Acceleration =
If the acceleration exceeds the limit (Pn.79), the response defined by Pn.81 "warning acc. stop mode"
is trig-
gered.
The drive, dependent on the programming, enters the status "24: ERROR! Maximum acceleration" (E.Acc) or
"106: ABN. Maximum acceleration" (A.Acc)
7.13.1.16 General power circuit error
Monitors for the internal hardware (e.g. fans) are integrated on some inverter types. If one of these monitoring
circuits reports an error, "12: general power circuit error" (E. PU) is triggered.
7.13.1.17 Phase loss
"Error! Phase loss" (E. UPh) is identified indirectly via the ripples in the DC link voltage.
If one power phase is missing, the waviness in the DC link is considerably increased under load. In no-load
operation or at small load, the error of the power phase is, however, not recognised. For this error, an automatic
restart cannot be programmed.
Phase loss detection at the output
If one of the output phases is interrupted during operation, this should be detected by the inverter.