Instrument cable transmission distance
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We have an electric valve on site; it is powered by 220V, uses a 24V switch signal for control, and the valve opening is adjusted via a 4-20mA signal. It is located about 500 meters away from the control cabinet. Do we need to use signal amplifiers for both the 24V switch signal and the 4-20mA signal?
It is not necessary to control the supply voltage; as long as it is greater than 5V, it will work. A 24V control voltage should come from a constant current source.
If you are concerned, you can use a 1.5 gauge wire; if the power cable and the signal cable are in the same conduit, a partition should be used to separate them.
With my 1.5 gauge wire, 2000 meters is no problem at all
Is it to use a 4–20 ma signal? Isn’t it just the attenuation due to long-distance transmission?
Simulation is fine; for switches, there might be a 3V voltage drop over 500 meters (1.5 volts per meter)
Come and take a look/learn from it. The fellow travelers upstairs have basically answered all the questions; just passing by: lol
For general insurance applications, the length of some signal wires should not exceed 1500 meters; otherwise, high resistance in the wires will affect the signals
Calculate the voltage drop by yourself to see if it meets the requirements.