Hitachi SJ2002 Series, Instruction Manual

Page: 159 / 306

SJ200
2
Inverter
Oper
ations
and Monitor
ing
4–17
External Signal for DC Braking
When the terminal [DB] is turned ON, the
DC braking feature is enabled. Set the follow-
ing 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.
Output
frequency
[FW, RV]
[DB]
Scenario 1
Output
frequency
Run command
from operator
Scenario 2
Output
frequency
Scenario 3
[DB]
[DB]
Run command
(from operator)
1
0
1
0
t
t
t
delay
1
0
1
0
1
0
1
0
A053
Option
Code
Terminal
Symbol
Function Name
Input
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, C002, C003, C004,
C005, C006
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.
1 2 3 4 5 6 L PCS
Example (requires input configuration—see
page
3–45 ):
See I/O specs on page 4–6 .
DB