Crompton Controls 3DPM1CHS/10 - Manual (Page 7)

7
Description of operation
Smooth-BRAKE with M3 connected
Controlled Stopping with feedback from motor
The M3 terminal provides voltage feedback from the motor during braking. The basic
setting is as page 6 but the braking torque setting will become the main adjustment and
switch the unit off a few seconds after coming to rest. The time setting needs to be long
enough to allow this to happen. Removal of the wire from the M3 terminal will remove the
voltage signal and braking will be to the torque and time settings only.
Operation with voltage feedback i.e. M3 connected
A three stage stop utilizing the voltage generated by the motor during braking as a speed
signal. The amount of voltage varies with the speed and amount of DC injection. With
high levels of DC and the motor spinning fast there is a strong signal.
Stage 1 The unit brakes at full until this signal reduces to approx 18%.
Stage 2 Then the braking strength is reduced.
There is an increase in voltage as standstill is approached to trigger the switch
to stage 3.
After this the voltage is too low to provide an accurate signal.
Stage 3 A low level of DC for a time is then used to bring the shaft to rest.
NOTE: The Time potentiometer provides an overriding switch off point adjustment from
0.2 to 50 sec.
Stages 2 and 3 have inbuilt timeouts dependent on the length of time in stage 1.
Stage 2 timeout equals two times the stage one time plus 2 sec.
Stage 3 timeout equals one times the stage one time plus 3.5 sec.
100%
20%
0%
Speed
Reducing
Voltage &
Braking
100%
50%
25%
100%
50%
Stage 1
Stage 2
Stage 3
Time set on pot
Timeout
Stage 2
Stage 3
Voltage from motor
100%
20%
0%
Speed
Reducing
Voltage &
Braking
100%
50%
25%
100%
50%
Stage 1
Stage 2
Stage 3
Time set on pot
Timeout
Stage 2
Stage 3
Voltage from motor
Braking Strength