Danfoss VLT FC 100 Series Programming Manual page 118

Parameter Description
14-10 Mains Failure
Option: Function:
Select the function at which the Adjustable
frequency drive must act when the threshold
set in 14-11 Mains Voltage at Mains Fault has
been reached or a Mains Failure Inverse
command is activated via one of the digital
inputs (par. 5-1*).
Only selection [0] No function, [3] Coasting or
[6] Alarm is available when 1-10 Motor
Construction is set to [1] PM non-salient SPM
[0] No function The energy left in the capacitor bank will be
*
used to "drive" the motor, but will be
discharged.
[1] Ctrl. ramp- The Adjustable frequency drive will perform a
down controlled ramp-down. 2-10 Brake Function
must be set to Off [0].
[3] Coasting The inverter will turn off and the capacitor
bank will back up the control card, thus
ensuring a faster restart when line power is
reconnected (for short power zags).
[4] Kinetic The Adjustable frequency drive will ride
back-up through by controlling speed for generative
operation of the motor utilizing the moment
of inertia of the system as long as sufficient
energy is present.
[6] Ctrl. alarm
suppress
Figure 3.34 Controlled Ramp-down - short line failure. Ramping
down to stop, followed by ramping up to reference.
®
VLT HVAC Drive Programming Guide
Figure 3.35 Controlled Ramp-down, longer line failure. Ramping
down as long as the energy in the system allows for it, then the
motor is coasted.
Figure 3.36 Kinetic Backup, short line failure. Ride through as
long as the energy in the system allows for it.
Figure 3.37 Kinetic Backup, longer line failure. The motor is
coasted as soon as the energy in the system is too low.
14-11 Mains Voltage at Mains Fault
Range:
Size related
MG11CD22 - VLT ® is a registered Danfoss trademark
Function:
[180 - 600 This parameter defines the threshold
*
V] voltage at which the selected
function in 14-10 Mains Failure should
be activated. The detection level is at
a factor sqrt(2) of the value in this
parameter.
3 3
3-91