Danfoss FC 300 Design Manual page 43

FC 300 Design Guide
Step-by-step Description
In hoisting/lowering applications, it must be possible to control an electro-mehanical brake.
• To control the mechanical brake any relay output or digital output (terminal 27 or 29) can be
used, if necessary use a suitable magnetic contactor.
• Ensure that the output stays voltage-free as long as the frequency converter is unable to drive
the motor, for example due to the load being to heavy or due to the fact that the motor has not
been dismounted yet.
• Select Mechanical brake control [32] in par. 5-4* (or in par. 5-3*) before connecting the me-
chanical brake.
• The brake is released when the motor current exceeds the preset value in par. 2-20.
• The brake is engaged when the output frequency is less than the frequency set in par. 2-21 or
2-22 and only if the frequency converter carries out a stop command.
NB!
For vertical lifting or hoisting applications it is strongly recommended to ensure that the load
can be stopped in case of an emergency or a malfunction of a single part such as a contactor,
etc.
If the frequency converter is in alarm mode or in an over voltage situation, the mechanical
brake cuts in.
Cabelling
EMC (twisted cables/shielding)
To reduce the electrical noise from the wires between the brake resistor and the frequency converter,
the wires must be twisted.
For enhanced EMC performance a metal screen can be used.
Smart Logic Control
The Smart Logic Control (SLC) is essentially a sequence of user defined actions (see par. 13-52) executed
by the SLC when the associated user defined event (see par. 13-51) is evaluated as TRUE by the SLC.
Events and actions are each numbered and are linked in pairs called states. This means that when event
[1] is fulfilled (attains the value TRUE), action [1] is executed. After this, the conditions of event [2] will
be evaluated and if evaluated TRUE, action [2]will be executed and so on. Events and actions are placed
in array parameters.
Only one event will be evaluated at any time. If an event is evaluated as FALSE, nothing happens (in the
SLC) during the present scan interval and no other events will be evaluated. This means that when the
Introduction to FC 300
MG.33.B7.02 - VLT is a registered Danfoss trademark
43