Hitachi WJ Series User Manual

Chapter 9 Inverter Functions
9-7-11
9.7.8 Stopping with DC Braking
 How to bring the inverter to a complete stop when the motor does not completely stop due to
external forces and a large load inertia?
 When stopping, you can stop motor rotation by applying DC braking (DB).
 There are three ways to apply DC braking (DB) when stopping.
- External DC braking:
This method involves assigning of "External DC braking [DB](07)" to the input terminal to
control DC braking by turning the [DB] terminal on and off. This is only available when
[A051] is set to "Disable(00)" or "Enable(01)".
- DC braking when stopping (Internal DC braking):
This sets [A051] to "Enable (01)".
This method starts DC braking when decelerating to a stop after turning the RUN
command off once the frequency falls below the "DC braking frequency [A052]".
- Frequency command DC braking (Internal DC braking):
This sets [A051] to "Enable (Output frequency < [A052]) (02)".
This method starts DC braking when the frequency command value and output frequency
fall below the "DC braking frequency [A052]".
 Set and operate the "DC braking force [A054]" and "DC braking active time at stop [A055]",
paying attention to the heat generated by the motor.
 When "Enable (Output frequency < [A052]) (02)" is set for "DC braking selection [A051]", DC
braking starts when both the frequency command and output frequency are at or below the "DC
braking frequency [A052]", even at startup. For details, also refer to "9.7.2 Starting with DC
Braking".
 When performing DC braking using the "External DC braking [DB] (07)" terminal, an overcurrent
or overvoltage error may occur during use at high output frequencies, or for large inertia loads.
Code
Item
Description
Data
[A051]
DC braking
selection
Internal DC braking: Disable
00
Internal DC braking: Enable
01
Internal DC braking: Enable (Output frequency < [A052])
02
[A052]
DC braking
frequency
When [A051] is set to " Enable (01)", DC braking is
applied when the frequency falls below this setting
when decelerating to a stop.
0.00 to 60.00 (Hz)
[A053]
DC braking delay
time
The delay time until DC braking is applied after either
the [DB] terminal is turned on, or the "DC braking
frequency [A052]" is reached. During this period, the
system is free running (output shutdown).
0.0 to 5.0 (s)
[A054]
DC braking force
Adjusts the DC braking force. When this is set to
100%, the maximum braking force is applied.
0 % (Weak: zero current)  100 % (Strong: rated current)
0 to 100 (%)
(ND mode)
0 to 70 (%)
(LD mode)
[A055]
DC braking
active time at
stop
Sets the DC braking time when [A056] is set to "Edge
operation".
0.0 to 60.0 (s)
[A056]
DC braking
operation
method selection
Edge operation:
DC braking is applied for the duration set by
[A055]. (Examples of operation 1-a to 7-a).
00
Level operation:
DC braking is performed only when set conditions
are met. (Examples of operation 1-b to 7-b).
01
[C001]
to
[C007]
Input terminal
function
External DC braking [DB]:
DC braking is applied when this signal is on. This
only applies when the "DC braking selection
[A051]" = 00, 01.
07
A
Q
!

Hitachi WJ Series Specifications

General

Brand	Hitachi
Model	WJ Series
Category	Inverter
Language	English