42
DC Braking
Applying DC current to the motor will brake the motor. Parameter 114,
DC Braking Current
, sets the DC braking current as a percentage of
the rated motor current. Parameter 115,
DC Braking Time
, sets the
amount of time that the DC current will be applied. Parameter 116,
DC
Brake Cut-in Frequency
, sets the frequency at which DC braking
begins when the motor decelerates during a stop.
If terminal 19 or 27 (parameters 303 or 304
Digital Input)
has been
programmed to
DC Braking Inverse
and shifts from logic 1 to logic 0,
the DC braking will be activated immediately.
When the start signal on terminal 18 changes from logic 1 to logic 0,
the DC braking will be activated when the output frequency becomes
lower than the brake cut-in frequency.
If a DC brake current is set in parameter 114, the drives switching
frequency will be limited to 4 kHz during the braking.
CAUTION
Motor Damage!
A high braking current supplied for a long time
will overheat the motor. Use only the DC braking
current and time required. Excessive braking
current may damage the motor.
Also, do not use DC braking function if inertia
of driven load is more than 20 times inertia of
motor. Excessive load inertia may damage the
motor.
114
DC Braking Current
(DC BRAKE CURRENT)
Value:
0 to 100%
★
50 %
The maximum value depends on the rated motor current.
Function:
This parameter is used for setting the DC braking current that is
applied:
1. When the DC brake frequency set in parameter 116
DC Brake
Cut-in Frequency
has been reached during a stop.
2. When DC brake inverse is active via terminal 19 or 27, or via the
serial bus.
The DC braking current will be active for the duration of the DC
braking time set in parameter 115
DC Braking Time
.
Description of choice:
To be set as a percentage value of the rated motor current set in
parameter 105
Motor Current.
100% DC braking current corresponds to the value set in parameter
105.
NOTE
Most HVAC applications do not required braking
or holding. It is suggested that parameter 114
remain set at 0 unless braking or holding torque
is required.
115
DC Braking Time
(DC BRAKE TIME)
Value:
0.0 to 60.0 sec.
✭
10.0 sec.
Function:
This parameter sets the time that the DC braking is active.
Description of choice:
Set the desired time.
116
DC Brake Cut-in Frequency
(DC BRAKE CUT-IN)
Value:
0.0 (OFF) to setting of parameter 202
✭
OFF
Function:
This parameter is used for setting the frequency at which DC braking
begins after a stop command is issued.
Description of choice:
Set the desired frequency for braking to begin upon deceleration.
✭
I
ndicates factory default setting. Numbers in brackets [ ] represent selection as displayed on the serial bus.
