14-10 Mains Failure
Option:
Function:
Ref
U
DC
14-15
A B C D
E
A
130BC922.10
U
DC
[V]
n [RPM]
t [S]
t [S]
14-11*1.35
A Normal operation.
B Mains failure.
C Kinetic back-up.
D Mains return.
E Normal operation: ramping.
Illustration 3.47 Kinetic Back-Up, Trip with
Recovery where Mains Return 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
is at
the normal level (U
DC, m
x 1.35).
14-11*1.35
Ref
U
DC
A B C D
E
F
130BC923.10
0
U
DC
[V]
n [RPM]
t [S]
t [S]
A Normal operation.
B Mains failure.
C Kinetic back-up.
D Mains return.
E Kinetic back-up, ramping to trip.
F Trip.
Illustration 3.48 Kinetic Back-Up, Trip with
Recovery, Trip Slow Ramp where Mains Return
below
Parameter 14-15 Kin. Back-up Trip
Recovery Level
, here a Slow Ramp is Used
If the ramp is quicker than the ramp-down speed
of the application, the ramping generates current.
This results in a higher U
DC
, which is limited using
the brake chopper/resistor brake.
14-10 Mains Failure
Option:
Function:
14-11*1.35
UDC
0
UDC
Ref
A
B
C
D
E
F
130BC924.10
U
n [RPM]
t [
s
]
DC [V]
t [
s
]
A Normal operation.
B
Mains failure.
C Kinetic back-up.
D Mains return.
E
Kinetic back-up ramping to trip.
F
Trip.
Illustration 3.49 Kinetic Back-Up, Trip with
Recovery where Mains Return below
Parameter 14-15 Kin. Back-up Trip Recovery
Level
, here a Quick Ramp is Used
NOTICE
For best performance of controlled ramp down and
kinetic back-up, set
parameter 1-03 Torque Characteristics
to
[0] Compressor
or
[1] Variable Torque
(no automatic
energy optimization should be active).
DC Voltage
Output Speed rpm
Over Voltage Control Level
Mains
Time
130B
T101.10
Par 14-11
Illustration 3.50 Controlled Ramp Down, Short Mains Failure.
shows ramping down to a stop followed by
ramping up to the reference.
Mains
Time
DC Voltage
Output Speed rpm
Over Voltage Control Level
130B
T108.10
Par 14-11
Illustration 3.51 Controlled Ramp Down, Longer Mains Failure.
shows ramping down as long as the energy
in the system allows it, then the motor coasts.
Parameter Description
VLT
®
AQUA Drive FC 202
134
Danfoss A/S © 05/2018 All rights reserved.
MG20OB02
3
3
Summary of Contents for VLT AQUA Drive FC 202
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