The frequency converter for constant pressure water supply has analog input, water supply pressure percentage setting (using mathematical calculation methods), PID value setting, various channel settings, and so on. Such complex settings would be confusing even for professional electricians, let alone routine maintenance personnel.
In fact, constant pressure water supply controllers and frequency converters have been used in combination for constant pressure water supply in the fields of water treatment, water purification, and water supply. Constant pressure water supply controllers simplify various settings and wiring, allowing even routine maintenance personnel to adjust the water supply settings. This makes operation more intelligent and maintenance simpler. So, would you like to learn what a professional constant pressure water supply system looks like?
Constant pressure water supply controllers are very common in the market, with many brands and relatively low prices. Let's talk about its functions:
1. The LCD displays Chinese characters, making parameter settings and alarms clear at a glance, and can be adjusted without a manual.
2. Convenient online parameter setting and adjustment; pressure can be set using the plus and minus keys. One-click PID value setting. Comprehensive alarm functions, including inverter fault alarm, remote pressure gauge disconnection and short circuit fault alarm, water level alarm indication, etc. Timed multi-stage rapid water supply. Low flow shutdown (i.e., stop function). Pump impeller start function, effectively preventing rust. One-use-one-compensation function (full-function version has one-use-three-compensation, with four pumps soft start for water supply by pressing the pressure). The wiring diagram of the TW2000 model is introduced below.
Back wiring terminals
As you can see, the controller has a total of 13 terminals. The function and wiring of each terminal are explained in detail below. Please refer to the wiring diagram of each terminal and the inverter.
Wiring diagram of frequency converter and constant pressure water supply controller
As you can see, terminals 1 and 2 are the power input terminals. Terminals 3 and 4 each control two contactors, C1 and C2. These are also the output terminals for constant pressure water supply. During operation, C1 and C2 alternate periodically to effectively prevent pump corrosion.
It also has a function where R1 is a fixed frequency pump and R2 is a fixed industrial frequency pump. When the frequency reaches 50 Hz and the actual pressure has not reached the set pressure, R2 will engage after a set time. When the actual pressure reaches the set pressure and the frequency is below 25 Hz, R2 will disengage.
5 is the operation command (forward rotation command). It is connected to the forward rotation command FWD of the frequency converter. The terminal symbols are different for different frequency converters. In fact, it is a digital terminal operation command.
6. Connect the DCM terminal to the CM terminal of the frequency converter. These two terminals are the common COM terminal that we commonly use.
7. CM2, like DCM, is the COM terminal, which is connected to the GND of the frequency converter, as shown in terminal 11 in the diagram.
Terminal 8 is connected to AI1 of the frequency converter. Terminal 12 in the diagram. Terminals 11 and 12 of the frequency converter in the diagram are actually the analog input terminals of the frequency converter.
9. The CT1 terminal is a multi-functional terminal. One function is external parking control. Another function is multi-speed clock operation control.
10. Terminal 10 is for external parking. The inverter stops working when it is connected to CM2.
Terminals 11, 12, and 13 are analog input terminals, the same as the analog input terminals of the frequency converter, and are connected to a remote pressure gauge or pressure transmitter.
Wiring diagram of the controller and frequency converter in actual operation
The TA and TC terminals of the frequency converter here are the fault output terminals of the frequency converter. Connecting them to the CT1 terminal of the controller constitutes an external shutdown due to a fault. KM1 and KM2 are manual operation contactors. KM3 and KM4 are constant pressure water supply contactors. This is a professional constant pressure water supply system with simple wiring and powerful functions.
