Motor holding brake

DANGER
	Risk of injury from hanging axes The optional motor brake is a holding brake and does NOT provide sufficient protection for persons. Hanging axes can fall and lead to severe injury. Steps to prevent: All hanging axes must be mechanically secured against falling with a fall arrester or a supplementary external brake, for instance. People must not stand under hanging loads

NOTICE
Material Damage!	Material damage of the holding brake! The brake optional integrated into the motor is a holding brake. The holding brake can be irreparably damaged if it is used as main brake. Steps to prevent: Make sure that the motor holding brake is open, when movement commands are sent to the motor. Make sure that the motor holding brake only closes after the motor shaft has come to a standstill.

 

A motor holding brake fixes the motor shaft in the energy-free state, for example in an application with a hanging axis.

The 'Motor brake control' function opens and closes the motor holding brake automatically, taking into account the parameterized response times of the motor holding brake.

The motor holding brake is opened and closed automatically and timely by the drive controller in fault-free operation by setting and resetting RF (controller enable).

In principle, the drive controller needs a control deviation at the input before outputting output values. As long as the axis is fixed by the motor brake, the control can not establish a holding torque. As soon as the motor brake is opened, an axis which is under load moves and a control deviation is generated. To reduce the control deviation, the controller (I-component in the speed controller) builds a holding torque. The magnitude of the compensating movement after the brake is released depends on the set control parameters and the mechanical conditions.

The torque feed-forward control principle can be used to apply a starter torque that builds up immediately while the brake is opening. The better the feed-foreward torque is adapted to the load, the lower the initial axial movement. The torque feed-forward control value can be specified externally via parameter (ID81 'Additive torque command value') or with the functions 'load model'.

 

See document Function descriptions (Part no. 203878), chapter Actuation of the motor holding brake.