Holding Brakes (Ex); Holding Brake Electrically Releasing; Holding Brakes Notes Regarding Safety - Bosch Rexroth MKE Series Project Planning Manual

90/131 Bosch Rexroth AG | Electric Drives
Operating Conditions and Application Notes
9.11

Holding Brakes (Ex)

9.11.1

Holding Brake Electrically Releasing

9.11.2

Holding Brakes Notes Regarding Safety

Rexroth MKE Synchronous Motors | Project Planning Manual
and Controls
Operation of the holding brakes of IndraDyn S motors is based on the "electrical
release" principle. Non-operative closed holding brakes open once the operat‐
ing voltage is applied.
The voltage supply of the holding brake has to be designed so as to guarantee
under the worst installation and operation conditions that a sufficient voltage of
24 Volt ±10 % is available at the motor in order to ventilate the holding brake.
(see also Rexroth IndraDrive drive system DOK-INDRV*-SYSTEM*****-PRxx-
EN-P chapter "Control voltage specification")
The switching voltage arriving at the motor is influenced by the
lenght of the cable as well as by its characteristics, such as e.g. the
resistance.
● For power cables designed for Bosch Rexroth up to a max.
length of 50 m, a minimum voltage of 22.8 V (24 V - 5 %) is
recommended on the drive control device..
● For power cables designed for Bosch Rexroth longer than
50 m, a minimum voltage of 23.4 V (26 V - 5 %) is recommen‐
ded on the drive control device.
t Connection time
1
t Disconnection time
2
Fig.9-21: Holding brake diagram
The electrically-released holding brake is used to hold the axes at a standstill
and when the "controller enable" signal is off. If the power supply voltage fails
and the controller enable signal is turned off, the electrically-released brake will
automatically shutdown.
Do not use the holding brake as an operational brake for moving
axes.
If the holding brake is engaged repeatedly on a drive in motion or the rated
brake torque is exceeded, premature brake wear can occur.
Observe the safety requirements during the system design.