What does electrical control represent in a PID diagram?
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In the PID plotting process, how are the motor’s start, stop, operation signals, and fault signals represented? Are there any relevant standards and specifications?
There are standard conventions: for example, YI, YL, and HS denote the operation light, fault light, start/stop function, respectively. Whether it is installed in a control room and whether it is connected to the DCS are indicated by outer circles and boxes. Just check the legend – it should be quite clear!
Reply to 2# playingnow23: Hello, may I ask which standard it is? ? I would like to know that too
It falls under the instrument specifications; if you want to understand it quickly, just look at any other PID diagram and examine the legend at the beginning – that will make it clear!
YL represents DI, and HS represents DO. I’m not quite sure about the rest; I hope someone can provide specific guidelines.
Signal to the electrical system: Start XSO-xxxx, Stop XSC-xxxx. Signal sent from the electrical system to the instruments: Operation signal XL-xxxx (*-xxxx is also common); Fault signal XA-xxxx
The symbols are a bit messy; let’s take a look at how it’s specified in the **standard legend**