Danfoss FC 300 Design Manual page 44

FC 300 Design Guide
Introduction to FC 300
SLC starts, it evaluates event [1] (and only event [1]) each scan interval. Only when event [1] is eval-
uated TRUE, the SLC executes action [1] and starts evaluating event [2].
It is possible to program from 0 to 20 events and
actions. When the last event / action has been
executed, the sequence starts over again from
event [1] / action [1]. The illustration shows an
example with three events / actions:
Extreme Running Conditions
Short Circuit (Motor Phase – Phase)
The frequency converter is protected against short circuits by means of current measurement in each of
the three motor phases or in the DC link. A short circuit between two output phases will cause an
overcurrent in the inverter. The inverter will be turned off individually when the short circuit current
exceeds the permitted value (Alarm 16 Trip Lock.
To protect the drive against a short circuit at the load sharing and brake outputs please see the design
guidelines.
Switching on the Output
Switching on the output between the motor and the frequency converter is fully permitted. You cannot
damage the frequency converter in any way by switching on the output. However, fault messages may
appear.
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MG.33.B7.02 - VLT is a registered Danfoss trademark