Hitachi WJ Series

Chapter 9 Inverter Functions
9-7-12
DC braking force and carrier frequency
 If "Carrier Frequency [b083]" is greater than 2 kHz, the DC braking force is limited as shown in
the figure below.
DC braking using the "External DC braking [DB]" terminal
 When applying DC braking using input signals from the control terminal, assign "External DC
braking [DB] (07)" to the input terminal.
 DC braking using the [DB] terminal is only available when the "DC braking selection [A051]" =
00, 01. DC braking is activated when the [DB] terminal is turned on, regardless of the RUN
command.
 DC braking operation varies depending on the edge operation/level operation settings in the
"DC braking operation method selection [A056]". Configure edge operation or level operation
settings to match the system in use, referring to the operation examples provided in the figure
below. When edge operation is selected, set the "DC braking active time at stop [A055]".
Maximum
braking force (%)
Carrier frequency [b083] (kHz)
0
100
50
10
3
15
13
11
9
5
7
(50)
(10)
(100)
2
* When the "DC braking delay time [A053]" is 0.0 (s), DC braking is immediately applied when the [DB] terminal is turned on.
◼ (Example 3) When the "DC braking delay time [A053]" is set to a value other than 0.0 (s), and the same operation
as that described in (Example 2) above is performed.
◼ (Example 1) Turning the [DB] terminal ON/OFF during operation.
(Example 1-b) [A056] = "Level operation (01)"
* In the case of edge operation, DC braking is applied for the duration of the [A055] setting from the ON edge input on the [DB] terminal.
In the case of level operation, DC braking is applied while the [DB] terminal is on.
(Example 2-a) [A056] = "Edge operation (00)"
(Example 2-b) [A056] = "Level operation (01)"
(Example 3-a) [A056] = "Edge operation (00)"
* If a value other than 0.0 (s) is set as the "DC braking delay time [A053]", DC braking is applied after free run (output shutdown) for the
allotted time. However, DC braking is immediately applied if the [DB] terminal is turned on when the inverter is stopped.
(Example 3-b) [A056] = "Level operation (00)"
(Example 1-a) [A056] = "Edge operation (00)"
◼ (Example 2) When turning [DB] terminal on/off during inverter deceleration when the RUN command is off.
The [A053] setting is 0.0 (s).
[A055]
ON
ON
RUN
command
[DB] terminal
Output
frequency
[A053]
DC braking
Free running
ON
ON
RUN
command
[DB] terminal
Output
frequency
[A053]
DC braking
Free running
[A055]
ON
ON
RUN
command
[DB] terminal
Output
frequency
DC braking
ON
ON
RUN
command
[DB] terminal
Output
frequency
DC braking
[A055]
ON
ON
RUN
command
[DB] terminal
Output
frequency
DC braking
ON
ON
RUN
command
[DB] terminal
Output
frequency
DC braking
!
A