Technical assistance: Questions regarding power operation

Oh my God, at your age you’re still a newbie!

Judgment by visual inspection, judgment using a multimeter, other inspection methods; Thermal resistor: 1. Check for continuity. The two output terminals (sometimes multiple) are connected (although there is a certain resistance); if they are open-circuited, it will definitely cause damage. Check whether the thermocouple protection tube is corroded and penetrated, or if there is any leakage. 1. Check for continuity. The two output terminals (sometimes multiple) are connected (although there is a certain resistance); if they are open-circuited, it will definitely cause damage. 2. Measure the voltage. The thermocouple outputs a voltage value; at a certain temperature, it generates a voltage signal ranging from a few to several dozen millivolts. 2. The resistance of modular thermocouples is generally not more than 2 ohms, while the resistance of wire-type thermocouples is generally not more than 50 ohms. Generally, if it’s greater than 1K, it can be determined to be broken.    Pressure transmitter, pressure transmitter pressure tap tube, differential pressure transmitter, 1 – measure current. 1.1 Zero-point check: Close the positive and negative pressure shut-off valves. Open the balance valve; at this point, the current of the electric differential pressure transmitter should be 4 mA. 1.2 Trend inspection: After reaching zero, each valve returns to its original open position, and the drain valve of the negative pressure chamber is opened. At this point, the output of the transmitter should be at its maximum; for electric differential pressure transmitters, this is above 20mA. If only the drain valve of the positive pressure chamber is opened, the output is at its minimum, namely 4 mA for the electric differential pressure transmitter.   When the drain valve is opened, very little or no fluid under test is discharged. This indicates that there is a blockage in the pressure guiding tube, and measures need to be taken to clear it. Inspection for blockage or solidification of the liquid in the differential pressure transmitter’s pressure guiding tube: This issue can be identified by observing the changes in the instrument’s output values over an extended period of time. When the instrument is operating normally, as the fluid in the pipeline passes through the throttling element, a large number of vortices with high frequency and amplitude are generated downstream. This is manifested as high frequencies of negative pressure values and pressure fluctuations of varying amplitudes; it is also reflected in the transmitter’s output, which fluctuates around a certain value. If the output value displayed by the transmitter does not change for an extended period of time (the recorder shows a straight line), it can be practically certain that the liquid inside the pressure guiding tube is blocked or has solidified. To confirm further, the balance valve can be quickly opened and then closed immediately; if the transmitter’s output value drops and then returns to normal, it can be determined that there is no issue with the transmitter’s circuit, and it can be inferred that the problem lies in a blockage or freezing of the liquid in the pressure guiding tube