4 dc-injection braking, Dc-injection braking, 5motor control (mctrl) – Lenze 8400 StateLine User Manual

Page 211: Danger

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Lenze · 8400 StateLine · Reference manual · DMS 12.0 EN · 06/2014 · TD05/TD14

211

5

Motor control (MCTRL)

5.9

Parameterisable additional functions

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

5.9.4

DC-injection braking

DC-injection braking allows the drive to be quickly braked to a standstill without the need to use an

external brake resistor.

• The braking current is set in

C00036

.

• The maximum braking torque to be generated by the DC braking current is approx. 20 ... 30 %

of the rated motor torque. It is lower than that for braking in generator mode with an external

brake resistor.

• The DC-injection braking can be activated manually via a control input of the application or

automatically ("Auto-DCB"). The two different modes are described in the following

subchapters.

Tip!
DC-injection braking has the advantage that it is possible to influence the braking time by

changing the motor current or the braking torque..
The automatic DC-injection braking (Auto-DCB) improves the starting performance of the

motor in case of V/f operation without speed feedback.

Short overview of the relevant parameters:

Note!

The DC-injection braking function (manually or automatically) is only possible for the

following motor control modes:

V/f characteristic control (VFCplus)

( 126)

V/f characteristic control - energy-saving (VFCplusEco)

( 144)

V/f control (VFCplus + encoder)

( 154)

Sensorless vector control (SLVC)

( 161)

Danger!

Holding braking is not possible when this braking mode is used!
For low-wear control of a holding brake, use the basic function "

Holding brake control

".

( 402)

Parameter

Info

Lenze setting

Value Unit

C00019

Auto-DCB: Threshold

• Operating threshold for activating DC-injection

braking

3 rpm

C00036

DC braking: Current

• Braking current in [%] based on rated device

current (

C00098

)

50 %

C00106

Auto-DCB: Hold time

0.500 s

C00107

DC braking: Hold time

• When "999.000 s" is set, the hold time is infinite.

999.000 s

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