Danfoss VLT AQUA Drive FC 202 Programming Manual page 136

Parameter Description
14-10 Mains Failure
Option:
3 3
134
VLT
Function:
A B C D A
U [V]
DC
U
DC
14-11*1.35
n [RPM]
Ref
14-15
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
the normal level (U x 1.35).
DC, m
A B C D E
U [V]
DC
U
DC
14-11*1.35
n [RPM]
Ref
0
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 , which is limited using
DC
the brake chopper/resistor brake.
Danfoss A/S © 05/2018 All rights reserved.
®
AQUA Drive FC 202
14-10 Mains Failure
Option:
E
t [S]
t [S]
NOTICE
For best performance of controlled ramp down and
kinetic back-up, set parameter 1-03 Torque Characteristics
is at
DC
to [0] Compressor or [1] Variable Torque (no automatic
energy optimization should be active).
F
t [S]
t [S]
Illustration 3.50 Controlled Ramp Down, Short Mains Failure.
Illustration 3.50 shows ramping down to a stop followed by
ramping up to the reference.
Illustration 3.51 Controlled Ramp Down, Longer Mains Failure.
Illustration 3.51 shows ramping down as long as the energy
in the system allows it, then the motor coasts.
Function:
A B C D
U DC [V]
U DC
U DC
14-11*1.35
n [RPM]
Ref
0
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
DC Voltage
Output Speed rpm
Over Voltage Control Level
Par 14-11
Time
Mains
DC Voltage
Output Speed rpm
Over Voltage Control Level
Par 14-11
Time
Mains
E F
t [s]
t [s]
MG20OB02