IMO SD1 Series - 4.3 Operations on the Keypad

SD1 Series Inverters Installation Guidelines
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VFD
Fuse
Input cable(three phase)
M
3~
Figure 3-17 Fuse configuration
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.
3.4.2 Protecting the motor and motor cables
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.
3.4.3 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 the AC power line and inverter output
terminals simultaneously.