19
ANTRIEBSTECHNIK
6
9
19
KEB COMBIVERT F4-C
Name: Basis
29.01.98
6
ANTRIEBSTECHNIK
Section
Page
Date
©
KEB Antriebstechnik, 1997
All Rights reserved
Chapter
Functional Description
Special Functions
F1>F2
M
H
= F1-F2
F1
F2
M
H
= 0
F1
F2
M
H
M
H
F=F1-F2
F=0
6.9.6
Braking Control
For applications in the range of lifting and lowering the control of the holding brake
can be taken over with this function. As tripping signal a digital output can be
programmed. The function is set programmable.
As shown in the opposite graphic a
torque equal to the power difference
F1-F2 must be built up, so that F1
does not drop after releasing the
brake. We refer to it as holding torque.
Thus a speed in the direction of the
holding torque must be preset for slip-
affected three-phase asynchronous
machines.
Mode of Functioning
6.9.6.b Principle of Braking control
At starting, triggered by activating the direction of rotation, a holding torque is built up.
For an adjustable time (Pn.52: starting time 1) the holding frequency (Pn.54: starting
frequency) is selected. As a precaution the monitoring of the load transfer by the
inverter can now be adjusted. Before releasing the brake the load is compared with
the minimum load level (Pn.58). If the load is smaller than this level error E. br is
triggered and the brake remains engaged. When the load transfer is ensured the
signal for releasing the brake is given after the expiration of the time and for a further
time (Pn.53: starting time 2), during which the brake is mechanically released, the
holding frequency is maintained. Subsequently it is accelerated to the adjusted setpoint
value.
At stopping, triggered by taking away the direction of rotation, the inverter drives to
the holding frequency (Pn.57: stopping frequency). After an adjustable time (Pn.54:
stopping time 1) the signal for applying the brake is given. After the expiration of
another time (Pn.55: stopping time 2), in which the brake takes over the load, it is
decelerated to standstill and the inverter changes to status LS.
Activating Brake
Disconnecting Brake
Pn.56 Stopping time2
0...100s (default 1s)
Pn.51 Braking control
Off
On; display boff/bon
On; display acc; dec; con
Direction of rotation
enabled
disabled
Pn.52 Starting time1
0...100s (default 1s)
Pn.54 Starting frequency
-50...50Hz (default 2Hz)
Pn.58 min. load level
0...100% (default 0%)
Pn.53 Starting time2
0...100s (default 1s)
set
reset
Pn.55 Stopping time1
0...100s (default 1s)
Pn.57 Stopping frequency
-50...50Hz (default 2Hz)
Switching condition 37
"Brake released" see
"digital outputs"
