Dc braking settings – Hitachi SJ100 User Manual

Page 88

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“A” Group: Standard Functions

Configur

ing

Dr

iv

e P

a

ra

m

e

ters

3–16

DC Braking Settings

The DC braking feature can provide
additional stopping torque when
compared to a normal deceleration to a
stop. DC braking is particularly useful
at low speeds when normal decelera-
tion torque is minimal. When you
enable DC braking, the inverter injects
a DC voltage into the motor windings
during deceleration below a frequency you can specify (A_52). The braking power
(A_54) and duration (A_55) can both be set. You can optionally specify a wait time
before DC braking (A_53), during which the motor will free run (coast).

CAUTION: Be careful to avoid specifying a braking time that is long enough to cause
motor overheating. If you use DC braking, we recommend using a motor with a built-in
thermistor, and wiring it to the inverter’s thermistor input (see

“Thermistor Thermal

Protection” on page 4–22

). Also refer to the motor manufacturer’s specifications for

duty-cycle recommendations during DC braking.

DC braking

Free run

Running

A 53

A 55

t

0

+

“A” Function

Run

Mode

Edit

Defaults

Func.

Code

Name /

SRW Display

Description

–FE

(CE)

–FU

(UL)

–FR

(Jpn)

Units

A_51 DC braking enable

Two options; select codes:
00... Disable
01... Enable

00

00

00

DCB SW OFF

A_52 DC braking frequency

setting

The frequency at which DC
braking occurs,
range is 0.5 to 10 Hz

0.5

0.5

0.5

Hz

DCB F 00.5Hz

A_53 DC braking wait time

The delay from the end of Run
command to start of DC
braking (motor free runs until
DC braking begins)

0.0

0.0

0.0

sec.

DCB WAIT 0.0s

A_54 DC braking during

deceleration

Applied level of DC braking
force, settable from 0 to 100%

0

0

0

%

DCB V 000

A_55 DC braking time for

deceleration

Sets the duration for DC
braking, range is 0.1 to 60.0
seconds

0.0

0.0

0.0

sec.

DCB T 00.0s

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