Frequency Inverter ST600 High-Performance Multifunction Series VFD Optional peripheral
accessories
-363-
Note: The insulation resistance is reduced if it is damp inside the motor. If it may be damp, you need
to dry the motor and then measure the insulation resistance again.
D.5 Breaker and electromagnetic contactor
You need to add a fuse to prevent overload.
You need to configure a manually manipulated molded case circuit breaker (MCCB) between the AC
power supply and VFD. The breaker must be locked in the open state to facilitate installation and
inspection. The capacity of the breaker needs to be 1.5 to 2 times the VFD rated input current.
According to the working principle and structure of breakers, if the manufacturer's regulation
is not followed, hot ionized gases may escape from the breaker enclosure when short-circuit
occurs. To ensure safe use, exercise extra caution when installing and placing the breaker.
Follow the manufacturer's instructions.
To ensure safety, you can configure an electromagnetic contactor on the input side to control the
switch-on and switch-off of the main circuit power, so that the input power supply of the VFD can be
effectively cut off when a system fault occurs.
Table D-3 Parameters of the optional accessories for standard and SP model VFDs
Breaker rated current
(A)
Fast-acting fuse
rated current (A)
Contactor rated
current (A)