Wiring Protection; Protecting The Inverter And Input Power Cable In Short-Circuit Situations; Protecting The Motor And Motor Cable In Short-Circuit Situations; Protecting The Motor Against Thermal Overload - INVT Goodrive 35 Series Operation Manual

Goodrive35 inverters

4.5 Wiring protection

4.5.1 Protecting the inverter and input power cable in short-circuit situations

Protect the inverter and input power cable in short circuit situations and against thermal overload.
Arrange the protection according to the following guidelines.
Note: Select the fuse as the manual indicated. The fuse will protect the input power cable from
damage in short-circuit situations. It will protect the surrounding devices when the internal of the
inverter is short circuited.

4.5.2 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 separate fuse to cut off the short-circuit current.

4.5.3 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.

4.5.4 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 in soft start, the inverter can be converted
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 AC power line and inverter output terminals simultaneously.
Fig 4-25 Fuse configuration
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Installation guidelines