Danfoss VLT Programming Manual page 43

Parameter Description
1-63 Slip Compensation Time Constant
Range:
Size related
*
s]
3 3
1-64 Resonance Dampening
Range:
100 % [0 - 500
*
%]
1-65 Resonance Dampening Time Constant
Range:
5 ms [5 - 50 ms] Set 1-64 Resonance Dampening and
*
3.3.6 1-7* Start Adjustments
1-71 Start Delay
Range:
0.0 s [0.0 - 120.0 s] The function selected in 1-80 Function at
*
1-73 Flying Start
Option:
42
Function:
[0.05 - 5.00 Enter the slip compensation reaction
speed. A high value results in slow
reaction, and a low value results in
quick reaction. If low-frequency
resonance problems arise, use a longer
time setting.
Function:
Enter the resonance dampening value. Set
1-64 Resonance Dampening and
1-65 Resonance Dampening Time Constant to
help eliminate high-frequency resonance
problems. To reduce resonance oscillation,
increase the value of 1-64 Resonance
Dampening.
Function:
1-65 Resonance Dampening Time Constant to
help eliminate high-frequency resonance
problems. Enter the time constant that
provides the best dampening.
Function:
Stop is active in the delay period.
Enter the time delay required before
commencing acceleration.
Function:
This function makes it possible to catch a motor
which is spinning freely due to a mains drop-out.
When 1-73 Flying Start is enabled, 1-71 Start Delay
has no function.
Search direction for flying start is linked to the
setting in 4-10 Motor Speed Direction.
Clockwise [0]: Flying start search in clockwise
direction. If not successful, a DC brake is carried
out.
Both Directions [2]: The flying start will first make a
search in the direction determined by the last
reference (direction). If not finding the speed it will
make a search in the other direction. If not
successful, a DC brake will be activated in the time
set in 2-02 DC Braking Time. Start will then take
place from 0 Hz.
MG.11.CB.02 - VLT
®
VLT HVAC Drive Programming Guide
1-73 Flying Start
Option:
[0] Disabled Select Disable [0] if this function is not required
*
[1] Enabled Select Enable [1] to enable the frequency converter
1-77 Compressor Start Max Speed [rpm]
Range:
0
rpm
*
1-78 Compressor Start Max Speed [Hz]
Range:
Size
related
*
®
is a registered Danfoss trademark
Function:
to "catch" and control a spinning motor.
Function:
[0.0 - The parameter enables "High Starting Torque".
max This is a function, where the Current Limit and
output Torque Limit are ignored during start of the
speed] motor. The time, from the start signal is given
until the speed exceeds the speed set in this
parameter, becomes a "start-zone" where the
current limit and motoric torque limit is set to
what is maximum possible for the drive/motor
combination. This parameter is normally set to
the same value as par. 4-11 Motor Low Speed
Limit. When set to zero the function is inactive.
In this "starting-zone" par. 3-82 Starting Ramp is
active instead of par. 3-41 Ramp 1 Up Time to
ensure extra acceleration during the start and
to minimize the time where the motor is
operated under the minimum speed for the
application. The time without protection from
the Current Limit and Torque Limit must not
exceed the value set in par. 1.79 Compressor
Start Max Time to Trip or the drive will trip with
an alarm [A18] Start Failed.
When this function is activated to get a fast
start then also par. 1-86 Compressor Min Speed
for Trip is activated to protect the application
from running below minimum motor speed e.g.
when in current limit.
This function allows high starting torque and
use of a fast starting ramp. To ensure the build-
up of a high torque during the start, various
tricks can be done through clever use of start
delay / start speed / start current.
Function:
[0.0 - The parameter enables "High Starting Torque".
par. This is a function, where the Current Limit and
4-14 Torque Limit are ignored during start of the
Hz] motor. The time, from the start signal is given
until the speed exceeds the speed set in this
parameter, becomes a "start-zone" where the
current limit and motoric torque limit is set to
what is maximum possible for the drive/motor
combination. This parameter is normally set to
the same value as par. 4-11 Motor Low Speed
Limit. When set to zero the function is inactive.
In this "starting-zone" par. 3-82 Starting Ramp is
active instead of par. 3-41 Ramp 1 Up Time to
ensure extra acceleration during the start and