Holding Brakes Safety Instructions - Bosch Rexroth MAD Project Planning Manual

MAD / MAF Asynchronous Housing Motors
Brake control
Functional test
9.10.2

Holding brakes safety instructions

The voltage supply of the holding brake is to be designed such that the volt‐
age available at the motor (24 volts +/- 5%) for releasing/applying the holding
brake is sufficient even in the most unfavorable case during installation and
operation (see also Rexroth IndraDrive Drive Systems DOK-INDRV*-SYS‐
TEM*****-PRxx-EN-P, Chapter "Specification of control voltage").
The switching voltage incoming at the motor is subject to the line
length and the cable properties, e.g., conductor resistance.
● A minimum voltage of 22.8 V (24 V - 5 %) is recommended
at the drive controller for ready-made Bosch Rexroth power
cables up to 50 m in length.
● A minimum voltage of 24.7 V (26 V - 5 %) is recommended
at the drive controller for ready-made Bosch Rexroth power
cables more than 50 m in length.
In order to detect a fault during operation early enough, a monitoring device
has to be provided to monitor the voltage supply for the brakes for undervolt‐
age.
Prior to commissioning and on request during operation, the brake has to be
tested for proper functioning via the brake test using the brake monitoring
command. A low torque is applied to the motor to check whether the brake
has been completely released. For additional information and data on the
availability, please refer to the functional firmware descriptions of Rexroth
controllers.
Observe the commissioning-related guidelines for holding brakes in chapter
chapter 12 "Operation of MAD/MAF motors" on page
Observe the safety requirements when designing the system.
DANGER
Secure vertical axes against dropping or sinking after switching off by:
● Mechanical locking of the vertical axis
● External brake, arrestor, clamping device or
● ensure sufficient weight compensation of the axes
The holding brakes supplied as standard and controlled by the controller
alone are not suitable for personal protection!
DANGER
Personal protection has to be achieved by means of overriding fail-safe
measures, such as e.g. danger zones that are sealed off by protective fences
or protective grids.
In addition to the information and notes on the holding brake given here, ad‐
ditional standards and guidelines have to be observed when designing the
system.
In European countries e.g.:
247.
Grievous bodily harm due to dangerous
movements from falling or sinking axes!
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Application notes