415

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%.

[FW,RV]

[DB]

Output frequency

Scenario 1

1

0

1

0

t

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.

Run command 1 from operator 0

1

[DB] 0

Output frequency

Scenario 2

t

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.

Scenario 3

Run command

1

from operator

0

 

[DB]

1

0

 

Output

delay

A053

frequency

 

 

t

Operations and Monitoring

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~C005

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.

Example (requires input configuration—see page 3–49):

 

 

DB

 

 

 

 

 

5

4

3

2

1

L

PCS

P24

See I/O specs on page 4–6.

Page 154
Image 154
Hitachi X200 Series External Signal for DC Braking, Option Code Terminal Symbol Function Name State Description