Hitachi WJ Series

Chapter 9 Inverter Functions
9-7-1
9.7 Selecting Start/Stop Modes
9.7.1 Starting with Gradually Increasing Voltage
 How to reduce the overcurrent at start when the minimum frequency is raised to generate
torque?
 This function gradually increases the voltage while outputting the minimum frequency when the
motor starts.
 If you want to prevent a current jump at start or an overcurrent trip occurs at start, increase the
value of "Reduced voltage start time [b036]".
 If you want to increase torque at start or the like, reduce the [b036] setting. However, a smaller
setting results in a start similar to a full-voltage start, which is more prone to an overcurrent trip.
 This function is effective when the control method is V/f control.
Code
Item
Description
Data
[b036]
Reduced voltage
start time
The output voltage is increased over a set time
from the start of operation until the voltage
command equivalent to the minimum frequency.
0 (Short time) to
255 (Long time)
[b082]
Minimum
frequency
The frequency at which the inverter output starts
when the RUN command is turned ON.
0.00 to 10.00 (Hz)
RUN command
Output frequency
Output voltage
Minimum frequency
[b082]
[b036] = 0
RUN command
Output frequency
Output voltage
Minimum frequency
[b082]
Small  [b036] → Large
◼ (Example 1) When the reduced voltage
start time is 0 ([b036] = 0)
◼ (Example 2) When the reduced voltage
start time is not 0 ([b036] ≠ 0)
A
!
Q