Hitachi WJ200 Series

4−20
External Signal for DC Braking
When the terminal [DB] is turned ON, the
DC braking feature is enabled. Set the
following parameters when the external DC
braking terminal [DB] is to be used:
• A053 – DC braking delay time setting.
The range is 0.1 to 5.0 seconds.
• A054 – DC braking force setting. The
range is 0 to 100%.
The scenarios to the right help show how DC
braking works in various situations.
1. Scenario 1 – The [FW] or [RV] terminal is
ON. When [DB] is ON, DC braking is
applied. When [DB] is OFF again, the
output frequency ramps to the prior level.
2. Scenario 2 – The Run command is applied
from the operator keypad. When the [DB]
terminal is ON, DC braking is applied.
When the [DB] terminal is OFF again, the
inverter output remains OFF.
3. Scenario 3 – The Run command is applied
from the operator keypad. When the [DB]
terminal is ON, DC braking is applied
after the delay time set by A053 expires.
The motor is in a free-running (coasting)
condition. When the [DB] terminal is OFF
again, the inverter output remains OFF.
Option
Code
Terminal
Symbol
Function Name State Description
07
DB External DC
Braking
ON Applies DC injection braking during deceleration
OFF Does not apply DC injection braking during
deceleration
Valid for inputs:
C001~C007
Example (requires input configuration—see
page 3–84):
See I/O specs on page 4–6.
Required settings
A053, A054
Notes:
• Do not use the [DB] input continuously or for a
long time when the DC braking force setting A054
is high (depends on the motor application).
• Do not use the [DB] feature for continuous or high
duty cycle as a holding brake. The [DB] input is
designed to improve stopping performance. Use a
mechanical brake for holding a stop position.
[FW,RV]
1
0
[DB]
1
0
Output
frequency
Scenario 1
t
Run command
from operator
1
0
[DB]
1
0
Output
frequency
Scenario 2
t
Run command
from operator
1
0
[DB]
1
0
Output
frequency
Scenario 3
t
delay
A053
DB
7654321L
PCS
P24
PLC