Danfoss VLT AutomationDrive FC 301 Programming Manual page 456

VLT AutomationDrive FC 301/302
Programming Guide
Op- Name Description
tion
A
B
C
If mains returns while in kinetic back-up at a speed below parameter 14-15 Kin. Back-up Trip Recovery Level, the
drive 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
U [V]
DC
U
DC
SP-11*1.35
n [RPM]
Ref
0
Illustration 86: Kinetic Back-up Trip w/Recovery, Slow Ramp, Mains Returns Below Parameter 14-15 Kin. Back-up Trip Recov-
ery Level
A
B
C
If the ramp is quicker than the ramp-down speed of the application, the ramping generates current. This results
in a higher U
A
U DC [V]
U DC,b
U DC
14-11*1.35
n [RPM]
Ref
0
Illustration 87: Kinetic Back-up Trip w/Recovery, Quick Ramp, Mains Returns Below Parameter 14-15 Kin. Back-up Trip Recov-
ery Level
A
B
C
[9] Kinetic The purpose of this function is to avoid mains failure trips (Alarm 36), for example, where mains is weak or can
back-
be disturbed by other motors being started directly. When the drive detects mains failure, the drive ramps
up,
down the motor using kinetic back-up and coasts the drive. The drive remains coasted for the time set in pa-
coast
rameter 40-14 Mains Loss Duration - the actual ramp-down time in KB. If mains returns after that time, the drive
ramps up again. When parameter 40-14 Mains Loss Duration = 60, the drive immediately restarts the ramp up if
the start command is still valid from PLC and mains voltage is back. When parameter 40-14 Mains Loss Duration
= <60, the drive waits for the timer in parameter 40-14 Mains Loss Duration to expire before restarting ramp up.
456 | Danfoss A/S © 2022.12
Normal operation
Mains Failure
Kinetic back-up
A B C D E F
t [S]
t [S]
Normal operation
Mains failure
Kinetic back-up
, which is limited using the brake chopper/resistor brake.
DC
B C D E F
t [S]
t [S]
Normal operation
Mains failure
Kinetic back-up
D Mains return
E Normal operation: Ramping
is at the normal level (U
DC DC,m
D Mains return
E Kinetic back-up, ramping to trip
F Trip
D Mains return
E Kinetic back-up ramping to trip
F Trip
AU275636650261en-000101 / 130R0334
Parameter Descriptions
x 1.35).