Computer Drive Installation Instructions

12 Functional Descriptions 10.94

12.19.5 DC link buffering and monitoring of generator minimum speed limit

12.20.5 DC link buffering and monitoring of generator minimum

speed limit

12.20.5.1 DC link buffering

An axis/spindle can buffer the DC link by means of generator-mode braking. This function can

be selected through appropriate parameterization of 611D machine data and activation of

generator operation by programming commands.

Generator operation

Drive MD 1634

600V/625V

ZK2 message:

DC link generator active

DC link voltage

Drive MD 1633

n_GEN

Drive MD 1632

Drive MD 1635

280V

Drive MD 1631

ZK2 message:

Generator speed < drive MD 1635

ZK2 message:

DC link voltage > drive

MD 1634

Actual speed value

When the DC link voltage drops below the minimum threshold value set in drive MD 1631, the

axis/spindle concerned switches from position-controlled or speed-controlled operation into an

operating mode controlled by the DC link. When the drive is braked (through input of speed

12–218

SINUMERIK 840C (IA)