Field Wiring And Earth Grounding; Leak Current And Countermeasure - SHENZHEN ENCOM ELECTRIC TECHNOLOGIES CO. EN500 Series Service Manual

4 EMC（Electromagnetic Compatibility）Explanation

4.2 Field wiring and earth grounding

⑴ inverter terminal motor connection wire
inverter terminal power connection wire（R,S,T terminal input wire）should keep
distance enough as possible as can.
⑵ ,V,W terminal 3 motor wires should be placed in metal tube or metal wiring U
tank as possible as.
Generally control signal wire should use shield cable, when shield layer
⑶
connect to inverter
closed to inverter side.
Inverter terminal earth grounding cable must directly connect to floor, it cannot
⑷
connect to earth grounding through other device, and the location of earth grounding
should close to inverter as possible as.
⑸ strong current cable(R,S,T,U,V,W) cannot parallel wiring closely with control
signal wire, and bundled together is prohibited. It should keep distance from over
20～60 cm（relative to strong current size). When it's necessary to intersect, it
should be orthogonal crossing, show as Fig.4-2.
earth grounding wire for strong current should separately connect to earth
⑹
grounding with control signal and sensor earth grounding wire for weak current.
⑺ Forbid to connect inverter input terminal(R

4.3 Leak current and countermeasure

The leak current flows through inverter input and output terminal for wire
capacitance and motor capacitance, and its size decided by the distributed
capacitance and carrier frequency. There are two kinds of leak current: leak
current to earth and wire-to-wire. Restraining methods as below:
diminish the cable length between inverter and motor.
⑴
install ferrite magnetic ring or output reactor at the inverter output terminal.
⑵
36
terminal, it should be the single end earth grounding which
控制信号线
Control signal wire
Fig.4-2 system wiring demand
（U,V,W terminal output wire）and
电源线或电动机线
Power wire or motor cable
,S,T) to other devices.