Danfoss VLT AutomationDrive FC 301 Programming Manual page 135

Parameter Descriptions
14-10 Mains Failure
Note:
Options [1], [2], [5], [7] are not active when the option [2] Torque
is selected in parameter 1-00 Configuration Mode.
Option: Function:
1. If U
DC
Fault*1.35*1.05
2. If the speed is above the reference. This
is relevant if the mains come back at a
lower level than before, e.g. 14-11 Mains
Voltage at Mains Fault*1.35*1.02. This
does not fulfil the criterion in point one
and the frequency converter tries to
reduce U
Mains Fault*1.35 by increasing the
speed. This will not succeed as the
mains cannot be lowered.
3. If running motoric. The same mechanism
as in point 2, but where the inertia
prevents that the speed goes above the
reference speed. This leads to the motor
running motoric until the speed is
above the reference speed and the
situation in point 2 occurs. Instead of
waiting for that criterion 3 is introduced.
[5] Kinetic The difference between kinetic back-up with and
back-up, without trip is that the latter always ramps down
trip to 0 RPM and trip, regardless of whether mains
return or not.
The function does not detect if mains return. This
is the reason for the relatively high level on the
DC-link during ramp down.
U [V]
DC
790 V
U DC
14-11*1.35
n [RPM]
Ref
0
Illustration 3.54 Kinetic Back-up Trip
A Normal Operation
B Mains failure
C Kinetic back-up
D Trip
Table 3.24 Legend to Illustration 3.54
Limitation:
See the introduction text in 14-10 Mains Failure
[6] Alarm
[7] Kin. Kinetic back-up with recovery combines the
back-up, features of kinetic back-up and kinetic back-up
®
VLT AutomationDrive FC 301/302 Programming Guide
> 14-11 Mains Voltage at Mains
to 14-11 Mains Voltage at
DC
A B C D
t [S]
t [S]
MG33MH02 - Rev. 2013-09-30
14-10 Mains Failure
Note:
Options [1], [2], [5], [7] are not active when the option [2] Torque
is selected in parameter 1-00 Configuration Mode.
Option: Function:
trip w with trip. This feature makes it possible to select
recovery between kinetic back-up and kinetic back-up with
trip, based on a recovery speed, configurable in
14-15 Kin. Backup Trip Recovery Level to enable
detection of mains returning. If mains do not
return, the frequency converter ramps down to 0
RPM and trips. If mains return while in kinetic
back-up at a speed above the value in 14-15 Kin.
Backup Trip Recovery Level, normal operation is
resumed. This is equal to [4] Kinetic Back-up. The
DC-level during [7] Kinetic back-up is 14-11 Mains
Voltage at Mains Fault* 1,35.
U [V]
DC
U
DC
14-11*1.35
n [RPM]
Ref
14-15
Illustration 3.55 [7] Kinetic Back-Up, trip with
recovery where mains return above 14-15 Kin.
Backup Trip Recovery Level.
A Normal Operation
B Mains failure
C Kinetic back-up
D Mains return
E Normal operation: ramping
Table 3.25 Legend to Illustration 3.55
If mains return while in kinetic back-up at a
speed below 14-15 Kin. Backup 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 ramps down on its own,
the ramping is done motoric and U
normal level (U
DC, m
U [V]
DC
U
DC
14-11*1.35
n [RPM]
Ref
0
Illustration 3.56 [7] Kinetic Back-Up, trip with
recovery, trip slow ramp where mains return
below 14-15 Kin. Backup Trip Recovery Level. In
this illustration a slow ramp is used.
A B C D A E
t [S]
t [S]
is at the
DC
*1.35).
A B C D E F
t [S]
t [S]
133
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