KEB COMBIVERT F5 BASIC - Page 231

6
919
KEB COMBIVERT F5
Name: Basis
18.04.02
6
Section PageDate
© KEB Antriebstechnik, 2002
All rights reserved
Chapter
Functional DescriptionSpecial Functions
6.9.6 Power-Off Function
It is the task of the Power-Off function to ensure a controlled deceleration of the
drive until standstill in case of undervoltage (e.g. due to power failure). The kinetic
energy of the rotating drive is used to support the inverter DC-link voltage. As a result
the inverter remains in operation and can decelerate the drive in a controlled manner.
Especially in the case of parallel running drives (e.g. textile machines) the uncontrolled
running down of the motors and the consequences resulting from it (thread breakage)
can be avoided.
The parameter Power-Off-Mode (Pn.44) switches on the function and determines the
basic behaviour:
876543210 Bit
Value Function
Switch on/off of Power-Off
xxxxxxxx0
0
off
xxxxxxxx1 1 on
Power-Off / start volta
g
e
xxxxxxx0x
0
Automatic determination of start volta
g
e
xxxxxxx1x 2 Adjustment of start volta
g
e with Pn.45
Determination of startin
g
jump
xxxxxx0xx
0
From the slip
x x x x x x 1 x x 4 From the utilization
Behaviour of drive at min. output
xxxx00xxx
0
Status Poff, modulation on, reset required
x x x x 0 1 x x x 8 as above, but restart after network return (Pn.52)
x x x x 0 0 x x x 16 Status PLS, modulation on, reset required
xxxx11xxx 24 reserved
reserved
xxx0xxxxx
0
reserved
xxx1xxxxx 32 reserved
Selection of setpoint
x00xxxxxx
0
Current volta
g
e
x01xxxxxx 64 DC-volta
g
e (Pn.50)
x10xxxxxx 128 actual volta
g
e, if actual frequenc
y
is > Pn.48
x11xxxxxx 192 Brakin
g
torque (Pn.47)
DC-link volta
g
e stabilization durin
g
Power-Off
0xxxxxxxx
0
Switched on
1xxxxxxxx 256 Switched off
Power-Off Mode (Pn.44)
Switch on Power-Off
(Pn.44 Bit 0)
The Power-Off function is switched on/off with Bit 0 of Pn.44. Parameter Pn.44 is an
Enter-parameter.
The Power-Off function starts when the DC-link voltage drops below a certain value,
the start voltage. The start voltage can be set automatically or manually depending
on Pn.44 Bit 1.
Tripping of Power-Off
+
-
Fig. 6.9.6.a Starting the Power-Off function
Auto-DC link voltage set
value measured at nop,
LS and constant running
Pn.45 starting voltage
200...800 V
Pn.46 Auto-start
voltage 50...90%
(default 80%)
Pn.44 Bit 1 starting voltage
0 auto detect starting
voltage
2 setting starting voltage by
Pn.45
DC-link voltage real value
Starting power off if
real value < set value