Author: yibiao

Pressure Switch Output Type 1. Core Diagnosis: The Circuit Mismatch Blind Spot In pump control panels, booster pump systems, hydraulic power units, cooling water circulation loops, and dry-run protection circuits, pressure switches act as critical binary safety interlocks. They are responsible for low-pressure alarms, high-pressure alarms, pump automated start/stop sequences, and hardware-level safety interlocks. However,…

Pressure Switch In pump control panels, booster pump systems, hydraulic stations, cooling water systems, and dry-run protection circuits, pressure switches are commonly used for low-pressure alarm, high-pressure alarm, pump start/stop, and safety interlock. However, many field problems are not caused by a failed pressure switch.They are caused by a mismatch between the pressure switch output…

Pressure Sensing In variable frequency drive (VFD) constant pressure water supply and secondary water supply systems, the stability of the PID closed-loop control relies entirely on the quality of the feedback signal. In many field applications, severe pressure feedback fluctuations and VFD frequency hunting/instability occur. The root cause is frequently not poorly tuned PID parameters,…

PID In a constant pressure water supply system, the VFD adjusts pump speed according to the pressure feedback signal from a pressure transmitter.If the PID parameters are not properly tuned, the system may show pressure oscillation, VFD frequency hunting, unstable pump speed, and repeated pressure overshoot. A typical control chain is: pressure transmitter → 4–20mA…

Thermal Flow Switch In Malaysia’s industrial market, reliable flow monitoring is essential for keeping pumps, cooling circuits, water treatment systems, process utilities and production lines operating safely. From water and wastewater treatment plants to palm oil processing, food and beverage production, HVAC systems, chemical plants and oil and gas related facilities, many applications require a…

Direct Answer PLC analog input impedance mismatch usually means the 4–20mA current loop load is not suitable. If the PLC input resistance is too high, or if display meters, isolators, external resistors or long cables are added in series, the pressure transmitter may not have enough voltage to drive the loop current up to 20mA….

Direct Answer When a pressure transmitter has no 4–20mA signal, the most common causes are not always sensor failure. They are often insufficient 24VDC power, reversed polarity, broken loop wiring, PLC analog input not included in the loop, or wrong PLC input configuration. A 4–20mA current loop usually includes a power supply, transmitter, receiver/controller and wiring…

Key Takeaways (TL;DR) What is the Fundamental Difference? In the field of industrial instrumentation, distinguishing between a conventional pressure sensor and a Micro Differential Pressure Sensor (MDPS) is crucial. Although both measure “pressure,” their underlying hardware designs and core technical specifications are fundamentally different due to massive variations in measurement references and scale dimensions. Conventional…

Direct Answer The most common mistake is misunderstanding how power, signal and PLC COM are related. A 2-wire pressure transmitter uses the same two wires for both power and 4–20mA signal transmission.A 3-wire pressure transmitter separates power positive, power negative and signal output. The signal usually shares the same reference as the power negative. Fluke explains that many 4–20mA…

In industrial automation applications—such as constant pressure water supply, water treatment skids, booster pump stations, and control panels—engineers frequently encounter a common challenge: How do you feed a single 4–20mA pressure transmitter signal into a PLC for central monitoring while simultaneously feeding it into a Variable Frequency Drive (VFD) for local PID closed-loop control? Incorrect…

Executive Summary: The Evolution of Fluid Security In my 15 years navigating the industrial automation and fluid control sectors, I have reviewed countless post-mortem failure analyses. The most painful lesson is always the same: the failure of an inconspicuous, sub-tier component can cause a catastrophic shutdown of a multimillion-dollar asset. If precision sensors represent the…