The well is a common source of water for private homes. Lifting fluid from depth and filling the line is provided by the pump. Frequent cycles of turning the unit on and off lead to wear of parts. To organize a safe operating mode, a well pump control unit is installed.
Purpose of automation for a well
Automatic control devices for submersible pumps are used to control their operation and protect them from unusual situations. Electronic or mechanical devices support the pressure parameters set by the consumer in the water supply network. In the event of an emergency in the form of power surges or lack of water, the automation prevents breakdown of an expensive unit.
The main components of the control unit:
- Pressure switch - provides turning the pump on and off in accordance with the setting of the minimum and maximum pressure threshold in the water supply system. The controller can be equipped with a manometer and a “dry run” sensor.
- Float switch - mounted on the pump, used to control the liquid level.
- A hydraulic accumulator is a sealed metal container with an elastic membrane inside into which water is pumped. Part of the tank is filled with air under pressure. The device is necessary to maintain a stable pressure.
- Press control or flow switch - the device has a check valve, serves to turn on the pump when the pressure drops. The device turns off the unit in the absence of fluid ("dry running"). Used in a system without a hydraulic accumulator.
Automation responds to changes in the physical parameters of a fluid: pressure, flow rate. Special relays control power surges, protect the motor windings from overheating.
Types and device of automation
According to the degree of automation, control units are divided into three generations.
First generation
Widespread use was given to the simplest type of automation for a borehole pump with a hydraulic accumulator and a pressure switch. It is available for self-installation and maintenance. Monitoring devices are compatible with submersible and surface units. The size of the storage tank depends on the total water consumption. Power is supplied to the pump via a pressure switch. When the pressure drops in the system, the contacts close, the pump turns on. It functions up to the upper pressure threshold. The cycle is regularly repeated. The hydraulic accumulator reduces the number of unit starts, compensates for water hammer.
Second generation
Automatic control is carried out by a unit with a set of sensors. Its basis is press control. The device provides adjustment of the supply and pressure of water in the system. In the event of an accident, it turns off the pump and performs an automatic restart. An electronic controller receives signals from sensors in the pipeline. The device is quiet, maintenance free. The appliance is installed up to the first pick-up point. There is an arrow on the body showing the direction of fluid movement. Blocks work without pressure vessels.
Third generation
The latest generation automation systems control the speed of the pump motor. It reaches operating power only with significant water consumption.A soft start is carried out, the resource of the mechanism is slowly being generated, energy is saved. Such devices are frequency converters. Automation has fine tuning, provides reliable protection of the engine from malfunctions in the electrical network. The pressure in the system remains unchanged with the simultaneous inclusion of several points of consumption. To compensate for leaks, a 2 liter tank is recommended. The cost of the frequency converter is much higher than the rest of the automation, it is 17-35 thousand rubles.
Principle of operation
Regardless of the level of automation, the well pump control system works according to a general principle. It turns on the unit when the pressure switch contacts are closed. The device is configured for two parameters: the upper stage, at which the pump is turned off, and the lower one, which starts pumping water into the system. In parallel or in the same housing, a dry-running sensor is installed. It prevents the mechanism from running without fluid. A relay may not be required if the pump is equipped with a float mechanism.
In modern automation systems for wells with submersible pumps, electronic control units are used. Devices do not require the installation of a hydraulic accumulator. They operate based on the performance of pressure sensors located in the pipeline.
Criterias of choice
Control systems are selected according to technical characteristics. Their parameters must meet the pressure criteria of the borehole pump and the needs of the house for water supply. If the unit is designed to use a small volume of water, it is enough to install a float switch. For correct operation of the system with average water consumption, a pressure switch and a hydraulic tank will be required. The number of liquid analysis points and pressure requirements are taken into account.
The control units of the second and third generation of automation carry out effective control of the pump, provide reliable protection against any overload. They are recommended for installation in rural cottages with permanent residence. A simple system of relays and storage tank is better to use in the country. Water supply in this case is required only in the warm period, there is no need to purchase expensive equipment.
The price of electronic and frequency units is much higher than the first-generation devices. Given the maintenance and repair of high-precision devices, few consumers choose modern automation. Electronic regulators surpass the set of relays and accumulators in technical specifications, but the cost makes them inaccessible to the mass buyer.
Features of installation and connection
The consumer can independently install the float switch and the control system of the first generation. The installation of electronic controllers and frequency converters is best entrusted to specialists. Control devices are located in a heated, dry room. The pressure switch is installed on the five-pin fitting before entering the accumulator. The remaining inputs are connected: to the pipe from the pump, wiring to the points of analysis, pressure gauge. In the area between the pump and the tank, a check valve crashes.
The float mechanism and dry run protection are installed on the pump before it is lowered into the well. For the correct operation of the control units, installation of filters is required.
Customization
Self-tuning of parameters is possible only on a mechanical pressure switch. It is carried out with the case open. Inside the device are two springs. By turning the larger part, the pump start pressure is adjusted. Loosening and tightening the small spring changes the difference between upper and lower pressure.
Before starting the system, it is recommended to check the air pressure in the hydraulic tank.When lowering the factory parameters, it is necessary to pump it with a compressor.
Advantages and disadvantages of using automation
Installation of control units saves consumers from manual control of the system. Using automatic devices has several advantages:
- Full control over the functioning of the water supply network is exercised.
- In a compact electronic unit, manufacturers assemble all the automation components.
- Using a regulator increases the life of the pump.
- Maintaining a constant pressure ensures comfortable use of plumbing fixtures.
For the convenience of consumers, the units are equipped with digital displays for tracking parameters. In the event of a failure, they restart themselves.
Disadvantages of automation:
- The operation of electronic devices depends on the voltage in the electrical circuit.
- Control units are very expensive.
- Control systems are not suitable for vibration pumps.
- The factory settings of the devices are not always suitable for a particular network; only a specialist can perform the adjustment.
For consumers, the main selection criterion remains the cost of control systems. The use of first-generation automation is advisable in conjunction with an inexpensive pump.
