Danfoss VLT AutomationDrive FC 301 Programming Manual page 233

Parameter Descriptions
14-10 Mains Failure
Options [1] Ctrl. ramp-down, [2] Ctrl. ramp-down, trip, [5] Kinetic
back-up, trip, [7] Kin. back-up, trip w recovery are not active when
the option [2] Torque is selected in parameter 1-00 Configuration
Mode.
Option: Function:
[5] Kinetic back- The difference between kinetic
up, trip back-up with and without trip is
that the latter always ramps down
to 0 RPM and trips, regardless of
whether mains returns or not.
The function does not detect if
mains returns. This is the reason for
the relatively high level on the DC
link during ramp down.
14-11*1.35
A Normal operation
B Mains failure
C Kinetic back-up
D Trip
Illustration 3.59 Kinetic Back-up
Trip
[6] Alarm
[7] Kin. back-up,
This option is valid in VVC
trip w
Kinetic back-up with recovery
recovery
combines the features of kinetic
back-up and kinetic back-up with
trip. This feature makes it possible
to select between kinetic back-up
M0013101
Programming Guide
the mains cannot be
lowered.
•
If running mechanically.
The same mechanism as
in point 2 applies, but the
inertia prevents the speed
from going above the
reference speed. This leads
to the motor running
mechanically until the
speed is above the
reference speed and the
situation in point 2 occurs.
Instead of waiting for that
criterion, point 3 is
introduced.
A B C D
U [V]
DC
790 V
U DC
t [S]
n [RPM]
Ref
0
t [S]
+
only.
Danfoss A/S © 10/2019 All rights reserved.
14-10 Mains Failure
Options [1] Ctrl. ramp-down, [2] Ctrl. ramp-down, trip, [5] Kinetic
back-up, trip, [7] Kin. back-up, trip w recovery are not active when
the option [2] Torque is selected in parameter 1-00 Configuration
Mode.
Option: Function:
and kinetic back-up with trip, based
on a recovery speed, configurable
in parameter 14-15 Kin. Back-up Trip
Recovery Level. If mains does not
return, the frequency converter
ramps down to 0 RPM and trips. If
mains returns while in kinetic back-
up at a speed above the value in
parameter 14-15 Kin. Back-up Trip
Recovery Level, normal operation is
resumed. This is equal to [4] Kinetic
Back-up. The DC level during [7] Kin.
back-up, trip w recovery is
parameter 14-11 Mains Fault Voltage
Level x 1.35.
14-11*1.35
A Normal operation.
B Mains failure.
C Kinetic back-up.
D Mains return.
E Normal operation: ramping.
Illustration 3.60 Kinetic Back-Up,
Trip with Recovery where Mains
Returns above
Parameter 14-15 Kin. Back-up Trip
Recovery Level
If mains return while in kinetic
back-up at a speed below
parameter 14-15 Kin. Back-up Trip
Recovery Level, the frequency
converter ramps down to 0 RPM
using the ramp and then trips. If
the ramp is slower than the system
ramping down on its own, the
ramping is done mechanically and
U
DC
1.35).
A B C D A E
U [V]
DC
U
DC
t [S]
n [RPM]
Ref
14-15
t [S]
is at the normal level (U x
DC, m
231
3 3