There is static electricity at the motor temperature sensor location; how to resolve this?
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The stator and bearing temperatures of the motors on site are monitored using built-in temperature sensors; currently, temperature fluctuations are occurring. Upon inspection, it was found that there is induced alternating current between the thermistor wires. Has anyone encountered this issue? How to handle it? Should the metal mesh covering the temperature extension cable be grounded in the on-site junction box, to prevent induced electricity from entering the control system? Thank you all!
Worried that induced electricity will enter the control system? Unless your cabinet isn’t grounded.
1. Use shielded cables； 2. The wiring cabinet has good grounding conditions ； 3. Twist the shield wire of the shielded cable and connect it properly to the cabinet ground ； Answer completed
The induced voltage is measured on the temperature primary element, not on the instrument cable leading to the cabinet, and the cable’s shielding layer is grounded inside the cabinet.
Try adding an isolation safety barrier to see if it helps.
What is this alternating current? Voltage and current? The thermistor itself outputs 4-20mA; could there be a leakage in the wires?