5.4 Stopping Modes
5.4.1 Coast to Stop
Coast to stop lets the motor slow at its natural rate, with
no control from the soft starter. The time required to stop
depends on the type of load.
5.4.2 TVR Soft Stop
Timed voltage ramp reduces the voltage to the motor
gradually over a defined time. The load may continue to
run after the stop ramp is complete.
Timed voltage ramp stopping can be useful for
applications where the stop time has to be extended, or to
avoid transients on generator-set supplies.
70%
60%
50%
30%
10%
40%
Time
V
olt
a
g
e
(%
full
volt
a
g
e)
20%
80%
90%
100%
177HA509.10
1
1
Parameter 1-11 Stop Time
Illustration 5.6 TVR Soft Stop
5.4.3 Adaptive Control
To use adaptive control to control stopping performance:
1.
Select
Adaptive control
from the
Stop Mode
menu.
2.
Set
parameter 1-11 Stop Time
.
3.
Select the required profile in
parameter 1-14
Adaptive Stop Profile
.
0
10%
20%
30%
40%
50%
Time
S
p
ee
d
60%
70%
80%
90%
100%
17
7
H
A
51
0
.1
0
1
2
4
3
1 Early deceleration
2 Constant deceleration
3 Late deceleration
4
Parameter 1-10 Stop Time
Illustration 5.7
Parameter 1-14 Adaptive Stop Profile
NOTICE
Adaptive control does not actively slow the motor down
and does not stop the motor faster than a coast to stop.
To shorten the stopping time of high-inertia loads, use a
brake function, see
The first adaptive control stop is a normal soft stop. This
stop type allows the soft starter to learn the characteristics
of the connected motor. The soft starter uses this motor
data during subsequent adaptive control stops.
NOTICE
Adaptive control regulates the load according to the
programmed profile. Stopping current varies according
to the selected deceleration profile and stop time.
The soft starter has to learn the characteristics of a new
motor:
•
If replacing a motor connected to a soft starter
programmed for adaptive control starting or
stopping.
•
If the soft starter has been tested on a different
motor before actual installation.
If
parameter 1-1 Motor Full Load Current
or
parameter
1-12 Adaptive Control Gain
is changed, the soft starter
automatically relearns the motor characteristics.
5.4.4 Pump Stopping
The hydraulic characteristics of pump systems vary consid-
erably. This variation means that the ideal deceleration
profile and stop time vary from application to application.
provides guidelines on selecting between
adaptive control profiles. For identification of the best
profile for the application, test all 3 profiles.
Product Features
VLT
®
Soft Starter MCD 500
38
Danfoss A/S © 05/2016 All rights reserved.
MG17K602
5
5
