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Description of the electrical environment for maintenance of the flowmeter inverter

The flow input of the flowmeter inverter often has overvoltage protection. However, if the high voltage of the input terminal acts for a long time, the input end of the inverter will be damaged. The inverter and the control cabinet should be electrically connected. If the actual installation is difficult, the copper core wire can be used for bridging. Therefore, the instrument and electronic system in the cabinet should use a metal casing to shield the inverter from interference with the instrument. Therefore, in actual operation, it is necessary to verify the input voltage of the inverter, the single phase is still the three-phase and the rated voltage of the inverter.
In particular, when the power supply voltage is not chaotic, there must be a voltage stabilizing device, otherwise it will cause serious consequences. Due to the rectification and frequency conversion, the inverter generates a lot of interference electromagnetic waves in the vicinity. These high-frequency electromagnetic waves have certain interference to the instruments and instruments around. The grounding of the inverter must be separated from the grounding point of the power equipment and cannot be grounded. If the electromagnetic interference is not handled well, the whole system will not work, resulting in failure or damage of the control unit. The shield of the signal input line should be connected to E(G), and the other end should not be connected to the ground. Otherwise, the signal will fluctuate and the system will not oscillate. Therefore, in the process of maintenance of the flowmeter inverter, we need to do the following two aspects:
1. Prevent electromagnetic interference.
2. Prevent the input terminal from overvoltage. All components should be grounded reliably. In addition, shielded control cables should be used for wiring between electrical components, instruments and meters, and the shielding layer should be grounded.
Accurate grounding of the grounding frequency converter is an important means to improve the agility of the control system and the noise capacity. The grounding resistance of the grounding terminal E(G) of the inverter is as small as possible. The cross-sectional area of the grounding conductor should be no less than 2mm and the length should be controlled within 20m.

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