Salicru CV50-008-4F User Manual page 27

4.4.2 Protecting the motor and motor cable in short-circuit situations
The inverter protects the motor and motor cable in a short-circuit situation when the motor cable is
dimensioned according to the rated current of the inverter. No additional protection devices are needed.
 If the inverter is connected to multiple motors, a separate thermal overload switch or
a circuit breaker must be used for protecting each cable and motor. These devices
may require a separated circuit breaker to cut off the short-circuit current.
4.4.3 Protecting the motor against thermal overload
According to regulations, the motor must be protected against thermal overload and the current must be
switched off when overload is detected. The inverter includes a motor thermal protection function that protects
the motor and closes the output to switch off the current when necessary.
4.4.4 Implementing a bypass connection
It is necessary to set power frequency and variable frequency conversion circuits for the assurance of
continuous normal work of the inverter if faults occur in some significant situations.
In some special situations, for example, if it is only used as soft start, the inverter can be conversed into power
frequency running after starting and some corresponding bypass should be added.
 Never connect the supply power to the inverter output terminals U, V and W. Power
line voltage applied to the output can result in permanent damage to the inverter.
If frequent shifting is required, employ mechanically connected switches or contactors to ensure that the motor
terminals are not connected to the AC power line and inverter output terminals simultaneously.
Installation Guidelines 27 - 144