Protect The Motor And Motor Cable In Short Circuit; Protect Motor And Prevent Thermal Overload; Bypass Connection - IMO HD2 IP Series Instruction Manual

HD2 IP55 High-ingress Protection Series inverter

4.5.2 Protect the motor and motor cable in short circuit

If the motor cable is selected based on rated inverter current, the inverter will be able to protect
the motor cable and motor during short circuit without other protective devices.


4.5.3 Protect motor and prevent thermal overload

According to the requirements, the motor must be protected to prevent thermal overload. Once
overload is detected, users must cut off the current. The inverter is equipped with motor thermal
overload protection function, which will block output and cut off the current (if necessary) to
protect the motor.

4.5.4 Bypass connection

In some critical occasions, industrial frequency conversion circuit is necessary to ensure proper
operation of the system when inverter fault occurs.
In some special cases, eg, only soft startup is needed, it will convert to power-frequency
operation directly after soft startup, corresponding bypass link is also needed.

If frequent switch-over is needed, users can use the switch which carries mechanical interlock
or a contactor to ensure motor terminals will not be connected to input power cables and inverter
output ends simultaneously.
If the inverter is connected to multiple motors, it is a must to 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.
Do not connect any power source to inverter output terminals U, V and W.
The voltage applied to motor cable may cause permanent damage to the
inverter.
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Installation Guide