How to ground the shielding of inverter motor cables

The grounding method of the inverter motor cable shield directly affects the suppression of common-mode noise and the system's EMC performance. Common strategies include: at the inverter output end, firmly connecting the cable shield to the inverter's metal casing or dedicated grounding terminal via a 360-degree conductive connection (such as a shielding clip or metal connector housing). At the motor end, depending on safety standards and EMC requirements, there are generally two approaches: one is to connect the shield to the motor casing's grounding terminal as well, achieving double-ended grounding. This provides a good return path for high-frequency common-mode noise, but requires good equipotentiality of the grounding systems at both ends; otherwise, ground loop interference may be introduced. The second approach is to leave the shield floating (unconnected) at the motor end, with only the inverter end grounded. This avoids ground loops, but high-frequency noise may couple through the motor's distributed capacitance, resulting in slightly poorer suppression, and safety requirements need to be assessed. Sometimes, a Y capacitor is used to connect the shield to the casing at the motor end as a high-frequency ground. The optimal method needs to be determined by testing and comparing the motor shaft voltage, bearing current, and radiated noise under different connection methods. [Company Name] provides various cable shielding and grounding components to support different grounding schemes.