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Siemens AG 2001 All rights reserved
SIMODRIVE 611 Planning Guide (PJU) – 05.01 Edition
Motor Selection, Position/Speed Sensing
3.1 Motor selection
The motor should be selected according to the mechanical and dynamic
response characteristics which it must fulfill. The motor overload capability
required depends on the magnitude and number of load peaks during the
operating time.
3.1.1 Motor protection
Motor protection circuit–breakers should be used to protect the motors which
only switch a signal contact when the motor is overloaded.
If the motor is isolated from the power module during operation with the drive
pulses enabled, there is a danger that the power module and control module
could be destroyed.
3.1.2 Motors with holding brake
The holding brakes mounted onto the motors are used to brake the motor at
standstill. It can also shorten the braking travel under emergency conditions.
However, the holding brake is not an operating brake.
Note
The motor holding brakes may only be actuated when the motor is at a stand-
still.
If the holding brake is actuated during operation or while the motor is rotating,
this results in increased wear and shortens the lifetime of the holding brake.
This means that holding brake failure must be taken into account when
engineering the drive system and a hazard analysis must be carried out.
If holding brakes are used for hanging loads, this must be carefully analyzed as
there is a high potential danger.
By traversing to a defined endstop, a reference quantity is obtained to monitor
the braking travel. The measured braking travel is an indication of the brake
wear.
Description
Hanging loads
Monitoring
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