JT550 Series Inverter Manual
Chapter 3 Electrical Installation
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3.2 Description of Peripheral Electrical Devices
Items
Function Descriptions
MCCB
Disconnect the power supply when over current occurs on downstream
devices
Residual Current
Circuit Breaker
(RCCB)
Since the output of the inverter is high-frequency pulse voltage,
high-frequency leakage occurs sometimes; When installing an RCCB
on the input side, it is recommended to choose the special-use RCCB.
It is suggested to choose the model “B” for RCCB, and the leakage
current is set to 300mA.
Contactor
Start and stop the inverter.
Avoid starting and stopping the inverter frequently by switching the
contactor on and off (less than twice per minute) nor use it to directly
start the inverter.
EMC
Input Filter
• Reduce the external conduction and radiation interference of the
inverter.
• Decrease the conducting interference flowing from the power
terminals to the inverter and improve the anti-interference capability
of the inverter.
AC Input
Reactor
• Improve the power factor of the input side;
• Eliminate the higher harmonics generation on the input side
effectively and prevent other devices from being damaged due to
distortion of the voltage waveform.
• Eliminate the imbalance among the power phases that causes the
imbalance of input current.
DC
Reactor
• Improve the power factor of the input side.
• Improve the efficiency and thermal stability of the inverter.
• Eliminate the impact of higher harmonics of the inverter input side
and reduce the external radiation and interference.
AC Output
Reactor
The output side of the inverter generally has much higher harmonics.
When the motor is far from the inverter, there is distributed
capacitance in the circuit and certain harmonics may cause resonance
in the circuit, bringing the following two effects:
• Impair the motor insulation performance and damage the motor on
the long run.
• Generate large leakage current and cause frequent protection of
tripping on the inverter. If the distance between the inverter and the
motor is greater than 100 m, an AC output reactor is recommended.
Table 3.1 Description of Peripheral Electrical Devices
