KEB COMBIVERT F5-A, Applications Manual, Page: 412 / 552

Page 7.13 - 38 COMBIVERT F5-A, -E, -H © KEB, 2012-10
Protective functions
Emergency stop with braking module (not for vector controlled with DSM)
Setpoint source: Brake torque (Pn.44 bit 6...7 = 3)
In this mode the drive is to be stopped as fast as possible. Since the recovered energy can be very high, a
braking resistor is necessary.
The DC-link voltage controller is not active. In v/f-characteristic operation, the setpoint of the active current
controller is the braking torque (Pn.47). In vector controlled operation, the drive decelerates with the abnormal
stopping-function (Pn.60, 61, 67; see chapter 7.13.5) and behaves dependent on the setting in Pn.44 Bit 3...4.
The drive supplies no energy anymore at low speed in v/f-characteristic operation. In this case, the control must
be very soft, to prevent fall back.
It is possible to adjust the restart (Pn.48). The controller parameters of the active current controller are lowered
to below this value, linearly with the base value.
Emergency stop without braking module (only V/f characteristic operation)
Setpoint source: voltage setpoint Pn.50 (Pn.44 Bit 6...7 = 1)
In some cases one can do without a braking module with the Emergency-stop function, if the losses in the motor
are very high at high DC-link voltage.
The voltage stabilization should be switched off in this case. This can be done with Pn.44 Bit 8 = 1 during
Power-Off.
The DC-link voltage control is active. Deceleration is always to standstill. Then the behaviour results from the
setting of Pn.44 bit 3...4.
At small speeds the drive supplies no more energy. In this case, the control must be very soft, to prevent fall
back.
It is possible to adjust the restart value (Pn.48). The controller parameters of the active current controller are
lowered to below this value, linearly with the base value.
Power off in vector controlled operation with DSM
Only the emergency-stop function with braking module can be activated in this operating mode. After triggering
of power off, the drive decelerates with the abnormal stopping-function (Pn.60, 61; see chapter 7.13.5) and
behaves dependent on the setting in Pn.44 Bit 3...4.
7.13.11 GTR7-control
The braking transistor (GTR7) serves to control a braking resistor.
In the factory setting, the GTR7 is operated dependent on the DC link voltage to discharge recovered energy.
Here, the GTR7 is active only if the converter (the modulation), too, is enabled.
With the parameters Pn.64 "GTR7 input selection", Pn.65 "special functions" and Pn.69 "GTR7 DC link voltage
level", the switching performance of the GTR7 can be modified.
7.13.11.1 Activation via digital input
An input for activation of the GTR7 can be defined with Pn.64.
Thereby, the activation of the braking transistors
of all inverters in a DC interconnection of several drives can be synchronised and the occuring braking energy
is distributed to all inverters.
The GTR7 controls the braking resistor, in this case, independent of the inverter state and the DC link voltage,
as soon as the input is active.
Exception: On opening the control release (noP), the GTR7 is always switched off for safety reasons.
I.e., as soon as a digital input is selected for activation of the braking transistor, the adjustments in Pn.65 con-
cerning the GTR7 and the parameter Pn.69 are without function.