7 actual value monitoring, Actual value monitoring, 8basic functions – Lenze 8400 motec User Manual

Page 277

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Lenze · 8400 motec · Reference manual · DMS 4.1 EN · 08/2013 · TD05

277

8

Basic functions

8.2

Holding brake control

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

8.2.1.6

Motor magnetising time (only with asynchronous motor)

When an asynchronous motor is used, first the magnetic field required for the holding torque is

created (which is already available when a synchronous motor is used) after the controller inhibit is

deactivated and before the brake is released:

[8-4]

Chronological sequence of the brake output signal

8.2.1.7

Actual value monitoring

If an actual value monitoring time > 0 s is selected in

C02593/1

, the actual speed time monitoring

is active.

• The monitoring time starts when the speed setpoint has reached the lower switching threshold

and the actual speed is still above this threshold. (see illustration

[8-7]

in chapter "

Process when

brake is closed

".)

• If the actual speed is still above the threshold when the monitoring time has expired, the brake

will be automatically applied in the automatic brake control mode (mode 12).

Motor magnetising time (200 ms)

CINH = controller inhibit

• The frequency related to the lower speed

threshold is output for 200 ms unless the

premagnetisation has not been

deactivated via bit 4 in

C02582

.

• The same frequency is output to the motor

during the release time set in

C02589/2

.

• The direction of rotation depends on the

settings in

C02582

(bit 2/3) and the

setpoint speed.

t

t

t

CINH

bBRKReleaseOut

I

BRK

200 ms

Œ

Note!

Function only possible if speed feedback via the digital input terminals DI1/DI2 is

available.

Encoder/feedback system

( 158)

Note!

In the Lenze setting, the actual speed time monitoring is deactivated (

C02593/1

= "0 s"),

i.e. the brake will only be applied when the actual speed has reached the lower switching

threshold if speed feedback is available.

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