Hitachi CONVENTION 14 instruction manual 4 15

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:
xA053 – DC braking delay time setting.
The range is 0.1 to 5.0 seconds.
xA054 – 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 FunctionName State Description
ON Applies DC injection braking during deceleration07 DB External DC
Braking OFF Does not apply DC injection braking during
deceleration
Validfor inputs:C001~C005
Requiredsettings A053, A054
Notes:
xDo 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).
xDo 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.
Example (requires input configuration—see
page 3–49):
See I/O specs on page 4–6.
5 4 3 2 1 L
PCS P24
DB
[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
415
Operations and
Monitoring
4 15
Operations and
Monitoring