Setting Parameters
01/02 AWB8230-1415GB
130
DC braking (DCB)
To activate DC braking for decelerating the motor:
• apply a Stop signal (PNU A051 = 01)
• activate the digital input configured as DB (
a
Section “Acti-
vate DC braking DB“, Page 88).
By applying a pulsed DC voltage to the motor stator, a braking
torque is induced in the rotor and acts against the rotation of the
motor. With DC braking, a high level of stopping and positioning
accuracy can be achieved.
Under PNU A051, specify whether DC braking is activated auto-
matically when the frequency set under PNU A052 is reached and/
or when the DB input is activated.
Under PNU A052, enter the frequency at which DC braking is acti-
vated when PNU A051 is set to 00.
Under PNU A053 enter the waiting time which is to elapse before
DC braking becomes active after activation of the DB input or
when the set startup frequency is reached.
Under PNU A054 enter the braking torque between 0 and 100 %.
Under PNU A055 enter the braking duration.
Under PNU A056, specify the braking behaviour when the DB
input is active:
• 00: DC braking starts when the DB input is activated and ends
only when the time defined under PNU A055 has expired.
• 01: Braking starts as soon as the DB input is active and ends
when the DB input is deactivated.
DC braking can also be activated before motor acceleration, for
example in lifting and conveying applications (releasing the
mechanical holding brake) or with drives which are operated using
process variables, such as fans, pumps and compressors.
Under PNU A057, set the braking torque before acceleration (0 to
100 %). The motor is then braked before starting.
Under PNU A058, set the braking duration during acceleration.
Under PNU A059, set the pulse frequency for DC braking. For
values above 5 kHz observe derating (see below).
Caution!
DC braking results in additional heating of the motor.You
should therefore configure the braking torque (PNU A054
and A057) as low and the braking duration (PNU A055
and A058) as short as possible.
PNU
Name
Adjustable in RUN mode
Value
Function
WE
Normal
Extended
A051
DC braking
–
j
00
Automatic DC braking disabled
00
01
Automatic DC braking activated
A052
Activation
frequency
–
j
0 to 60 Hz
When PNU A051 is set to 01, DC braking is activated when
the actual frequency falls below the frequency entered here.
0.50
A053
Waiting time
for decelera-
tion
–
j
0 to 5 s
When the frequency set with PNU A052 is reached or when
the DB input is activated, the motor coasts for the time
entered here before DC braking is activated.
0.0
A054
Braking torque
for decelera-
tion
–
j
0 to 100%
Setting range for the braking torque during motor decelera-
tion.
0
A055
Braking dura-
tion for decele-
ration
–
j
0 to 60 s
The time during which DC braking is active during decelera-
tion.
0.0
A056
Behaviour on
activation of
the DB input
–
j
00
DC braking starts when the DB input is activated and ends
only when the time defined under PNU A055 has expired.
01
01
Braking starts as soon as the DB input is active and ends
when the DB input is deactivated.
A057
Braking torque
for accelera-
tion
–
j
0 to 100%
Setting range for the braking torque before the motor is
accelerated.
0
For Moeller Electric Sales and Support call KMparts.com (866) 595-9616
