Lenze 9212, Operating Instructions Manual, Page: 58 / 86

54
Setting course:
1. Select a medium speed as set value according to the occuring
speed range of the system.
2. Switch-off the mains.
The oscillogramme shows the reaching of the undervoltage
threshold on channel 2, the DC-bus voltage decreases slowly
(see fig. 1)
U
G
*
c
C 236
V m in
t
1
V
B r
t1 = Start of the DC-bus control
c
= Undervoltage threshold
reached
fig. 1: Start of the setting
DC-bus voltage during DC-bus control
3. Increase C079 to reach the undervoltage threshold at a speed
as low as possible. For very small final speed values, you may
reduce C228.
4. Repeat steps 1.) to 3.) at maximum and minimum system
speed.
5. Reduce C080 at maximum system speed until the DC-bus
voltage does no longer overshoot the brake-chopper threshold
(see fig. 2).
You may also reduce C237 to limit the speed decrease during
deceleration.
U
G
*
c
C 236
V m in
t
1
V
B r
t1 = Start of DC-bus control
c
= Undervoltage threshold
reached
fig. 2: Real setting
DC-bus voltage during DC-bus control
6. The increase of the V
z
acceleration integrator C228 prolongs the
deceleration period.
7. Save the setting under C003.