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© Siemens AG 2008 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 05/2008 Edition
Motor Selection, Position/Speed Sensing
3.1 Motor selection
The motor type should be selected according to the mechanical and dynamic
requirements placed on the motor.
3.1.1 Motor protection
Motor–protection circuit–breakers should be used to protect the motors. When
the motor has an overload condition, it only switches a signal contact.
If the motor is separated from the power module with the pulses enabled during
operation, then there is the danger that the power module will destroy itself to-
gether with the control unit. Because of the harmonic oscillations in the current,
set approx. 10% above the rated current!
3.1.2 Motors with holding brake
The holding brake mounted onto the motors is used to brake the motor when it
is already at a standstill. In an emergency, it can also additionally reduce the
braking travel. The holding brake is not an operational brake.
Notice
The motor holding brakes should only be actuated at standstill.
If the holding brake is operated during operation or while the motor is turning,
this results in increased wear and shortens the lifetime of the holding brake.
This is the reason that failure of the holding brake must already be taken into
consideration when engineering the system. A hazard analysis must be
performed.
!
Danger
Special attention and consideration must be given when holding brakes are
used for suspended (hanging) loads (injury, crushing, possibility of death,
machine damage) as this application represents a high potential hazard.
Description
Suspended
(hanging) loads
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