The current at the DCS terminal cabinet does not match the current at the field valve terminals
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The DCS outputs an AO signal of 4–20 mA; by removing the remote cable at the terminal cabinet, the current measured at the terminal holes is consistent with the DCS command. However, the terminal hole current measured after rewiring did not match the DCS command. When the valve is instructed to be opened to 50%, the DCS terminal reads 12mA when measured directly; after wiring, it reads 8.33mA. At the valve’s connection point on site, the reading is 10.1mA. The valve itself has been tested and found to be in good condition – could the problem lie with the cables?
Remove the cable insulation to see if the shielding layer has been scratched and made in contact with ground
The cable seems to be damaged; try using another wire