3-17
(6)
Motor Line-to-Line Resistance
(Cn-12)
(7)
Motor Iron-Core Loss
(Cn-13)
•
It is for torque compensation function. The default setting depends upon the
inverter capacity (Sn-01). Normally, the setting does not need to be altered. See
Table 10~11 on page
3-39.
(8)
DC Injection Braking Starting Frequency
(Cn-14)
(9)
DC Injection Braking Current
(Cn-15)
(10)
DC Injection Braking Time at Stop
(Cn-16)
(11)
DC Injection Braking Time at Start
(Cn-17)
•
The DC injection braking function decelerates by applying a DC current to the
motor. This happens in the 2 cases:
a. DC injection braking time at start: It is effective for temporarily stopping and then
restarting, without regeneration, a motor coasting by inertia.
b. DC injection braking time at stop: It is used to prevent coasting by inertia when the
motor is not completely stopped by normal deceleration when there is a large load.
Lengthening the DC injection braking time (Cn-16) or increasing the DC injection
braking current (Cn-15) can shorten the stopping time.
•
For the DC injection braking current (Cn-15), set the value for the current that is
output at the time of DC injection braking. DC injection braking current is set as a
percentage of inverter rated output current, with the inverter rated output current
taken as 100%.
•
For the DC injection braking time at start (Cn-17), set the DC injection braking
operating time when the motor is started.
•
For the DC injection braking starting frequency (Cn-14), set the frequency for
beginning DC injection braking for deceleration. If the excitation level is less than
the Min. output frequency (Cn-07), the DC injection braking will begin from Min.
output frequency.
•
If the DC injection braking time at start (Cn-17) is 0.0, the motor starts from the
Min. output frequency and no DC injection braking are enabled.
•
If the DC injection braking time at stop (Cn-16) is 0.0, no DC injection braking is
enabled. In this case, the inverter output will be blocked off when the output
frequency is less than the DC injection braking at start frequency (Cn-14).
Cn-14
DC injection braking
starting frequency
Cn-07
Min. output frequency
Cn-17
DC injection braking at start
Cn-16
DC injection braking at stop
Fig. 20.
DC injection braking time chart