INVT Goodrive350-19 Series Operation Manual page 52

Goodrive350-19 Series VFD for Crane
4.5 Wiring protection
4.5.1 Protecting the VFD and input power cable in case of short circuit
The VFD and input power cable can be protected in case of short circuit, avoiding thermal overload.
Carry out protective measures according to the following figure.
Note: Select the fuse according to the manual. In case of short circuit, the fuse protects input
power cables to avoid damage to the VFD; if internal short-circuit occurs to the VFD, it can
protect neighboring equipment from being damaged.
4.5.2 Protecting the motor and motor cable in case of short circuit
If the motor cable is selected based on VFD rated current, the VFD is able to protect the motor cable
and motor during short circuit without other protective devices.
If the VFD is connected to multiple motors, use a separated thermal overload switch
or breaker to protect the cable and motor, which may require the fuse to cut off the
short circuit current.
4.5.3 Protecting the motor against thermal overload
The motor must be protected against thermal overload. Once overload is detected, current must be
cut off. The VFD is equipped with the motor thermal overload protection function, which can block
output and cut off the current (if necessary) to protect the motor.
4.5.4 Bypass connection
In some critical scenarios, the power/variable frequency conversion circuit needs to be configured to
ensure proper operation of the system when a fault occurs to the VFD.
In some special scenarios, such as in soft startup, power-frequency running is directly performed after
the startup, which requires bypass connection.
Do not connect any power source to the VFD output terminals U, V, and W. The
voltage applied to the motor cable may cause permanent damage to the VFD.
If frequent switchover is needed, you can use the switch that carries mechanical interlock or a
contactor to ensure motor terminals are not connected to input power cables and VFD output ends
simultaneously.
VFD
Input cable
Fuse
Figure 4-24 Fuse configuration
-40-
Installation guidelines
M3 ~