EM11 User’s Manual
5. Description of Function Codes
47
frequency.
If the pre-excited time is not 0, the frequency inverter pre-excites firstly before startup, improving the
dynamic response of the motor.
Code
Parameter Name
Setting Range
Default
b1-01
Rotational speed tracking
mode
0: From frequency at stop
1: From zero speed
2: From maximum frequency
0
To complete the rotational speed tracking process within the shortest time, select the proper mode in which
the frequency inverter tracks the motor rotational speed.
0: From frequency at stop
It is the commonly selected mode.
1: From zero frequency
It is applicable to restart after a long time of power failure.
2: From the maximum frequency
It is applicable to the power-generating load.
Code
Parameter Name
Setting Range
Default
b1-02
Rotational speed tracking
speed
1~100
20
In the rotational speed tracking restart mode, select the rotational speed tracking speed. The larger the value
is, the faster the tracking is. However, too large value may cause unreliable tracking.
Code
Parameter Name
Setting Range
Default
b1-03
Startup frequency
0.00~10.00 Hz
0.00 Hz
b1-04
Startup frequency holding
time
0.0s~100.0s
0.0s
To ensure the motor torque at frequency inverter startup, set a proper startup frequency. In addition, to build
excitation when the motor starts up, the startup frequency must be held for a certain period.
The startup frequency (b1-03) is not restricted by the frequency lower limit. If the setting target frequency is
lower than the startup frequency, the frequency inverter will not start and stays in the holding state.
During switchover between forward rotation and reverse rotation, the startup frequency holding time is
disabled. The holding time is not included in the acceleration time but in the running time of simple PLC.
Example 1:
b0-03 = 0
The frequency source is digital setting.
b0-12 = 2.00 Hz
The digital setting frequency is 2.00 Hz.
b1-03 = 5.00 Hz
The startup frequency is 5.00 Hz.
b1-04 = 2.0s
The startup frequency holding time is 2.0s.
In this example, the frequency inverter stays in the holding state and the output frequency is 0.00 Hz.
Example 2:
b0-03 = 0
The frequency source is digital setting.
b0-12 = 10.00 Hz
The digital setting frequency is 10.00 Hz.
b1-03 = 5.00 Hz
The startup frequency is 5.00 Hz.
b1-04 = 2.0s
The startup frequency holding time is 2.0s.
In this example, the frequency inverter accelerates to 5.00 Hz at 2s, and then accelerates to the set frequency
10.00 Hz.
Code
Parameter Name
Setting Range
Default
b1-05
Startup DC braking current/
Pre-excited current
0%~100%
0%
b1-06
Startup DC braking time/
Pre-excited time
0.0s~100.0s
0.0s
5. Description of Function Codes
EM11 User’s Manual
48
Startup DC braking is generally used during restart of the frequency inverter after the rotating motor stops.
Pre-excitation is used to make the frequency inverter build magnetic field for the asynchronous motor before
startup to improve the responsiveness.
Startup DC braking is valid only for direct start (b1-00 = 0). In this case, the frequency inverter performs
DC braking at the setting startup DC braking current. After the startup DC braking time, the frequency
inverter starts to run. If the startup DC braking time is 0, the frequency inverter starts directly without DC
braking. The larger the startup DC braking current is, the larger the braking force is.
If the startup mode is pre-excited start (b1-00 = 3), the frequency inverter firstly builds magnetic field based
on the set pre-excited current. After the pre-excited time, the frequency inverter starts to run. If the
pre-excited time is 0, the frequency inverter starts directly without pre-excitation.
The startup DC braking current or pre-excited current is a percentage of motor rated current.
Code
Parameter Name
Setting Range
Default
b1-07
Stop mode
0: Decelerate to stop
1: free stop
0
0: Decelerate to stop
After the stop command is enabled, the frequency inverter decreases the output frequency according to the
deceleration time and stops when the frequency decreases to zero.
1: Free stop
After the stop command is enabled, the frequency inverter immediately stops the output. The motor will free
stop based on the mechanical inertia.
Code
Parameter Name
Setting Range
Default
b1-08
DC braking initial frequency
of stopping
0.00 Hz ~ maximum frequency
0.00 Hz
b1-09
DC braking waiting time of
stopping
0.0s~100.0s
0.0s
b1-10
DC braking current of
stopping
0%~100%
0%
b1-11
DC braking time of stopping
0.0s~100.0s
0.0s
b1-08 (Initial frequency of stop DC braking)
During the process of decelerating to stop, the frequency inverter starts DC braking when the running
frequency is lower than the value set in b1-08.
b1-09 (Waiting time of stop DC braking)
When the running frequency decreases to the initial frequency of stop DC braking, the frequency inverter
stops output for a certain period and then starts DC braking. This prevents faults such as over current caused
due to DC braking at high speed.
b1-10 (Stop DC braking current)
This parameter specifies the output current at DC braking and is a percentage relative to the motor rated
current. The larger the value is, the stronger the DC braking effects, but the more heat the motor and
frequency inverter emit.
b1-11 (Stop DC braking time)
This parameter specifies the holding time of DC braking. If it is set to 0, DC braking is cancelled. The stop
DC braking process is shown in the following figure.
