Solar borehole pump automation and water tank installation

Introduction to solar borehole pump automation

A solar borehole pumping system can be equipped with automatic controls that help manage water storage, prevent tank overflow, and reduce the risk of pumping when the borehole water level is too low. Automation is particularly useful for homes, farms, apartment buildings, schools, livestock facilities, and commercial properties that need a dependable water supply.

A properly designed automated system combines the solar panels, pump controller, submersible pump, water storage tank, level sensors, rising main pipe, and suitable protective equipment. The control arrangement must be compatible with the selected pump and controller.

Pro-Logic Technologies Limited works with Hydrosol Drilling Solution on borehole-related enquiries and water pumping requirements. Customers planning an automated solar borehole system should establish their water demand, borehole yield, tank capacity, and control requirements before selecting equipment.

What is an automated solar borehole water system?

An automated solar borehole water system uses sensors, switches, or control equipment to manage pumping according to defined operating conditions. For example, the system may stop pumping when a storage tank becomes full and permit pumping again when the water level falls.

A separate borehole water-level sensor may stop the pump when the water level falls below a specified threshold. This function helps protect the pump from running without sufficient water.

Some solar pump controllers include dedicated terminals for tank switches and borehole probes. Other arrangements require compatible interface equipment, relays, or a separate control panel.

The precise design depends on the pump motor, controller model, sensor type, electrical ratings, and required operating sequence. Not every controller supports every automation feature.

Why automate a solar borehole pump?

Automation can reduce the need for someone to operate the pump manually throughout the day. It can also help prevent water from overflowing the tank and reduce the risk of dry running when suitable level protection is installed.

A correctly configured system can improve water management by matching pumping operation to tank levels and available water. It may also provide fault indicators that help a technician identify problems more quickly.

Automation does not remove the need for maintenance or supervision. Sensors can fail, cables can become damaged, and a borehole may produce less water than expected. The system should be inspected periodically to confirm that its protective functions remain operational.

Main components of an automated solar pumping system

Solar panels

The solar array supplies electrical energy to the pumping system. Its capacity and electrical configuration must suit the pump controller and the required daily water volume.

The panels should be positioned to receive adequate sunlight, with attention to shading, mounting strength, cable routing, and environmental exposure.

Solar pump controller

The controller manages the pump's electrical operation. Depending on the model, it may include motor control, overload protection, dry-run detection, fault indications, and dedicated inputs for level switches.

The controller's actual features should be verified from its documentation. Additional automation equipment may be required if the controller does not support the desired functions.

Submersible borehole pump

The pump lifts water from the borehole and delivers it through the rising main pipe. It must be selected for the required flow rate and total dynamic head while respecting the borehole's sustainable yield.

Storage tank

The tank stores water for use when pumping is unavailable or demand exceeds the immediate pump output. Its capacity should be based on the property's water requirements and the expected pumping schedule.

Level sensors and float switches

These devices detect water levels and send signals to compatible control equipment. Their functions may include stopping the pump when a tank is full or preventing pumping when the borehole water level is too low.

Valves, pipes, and protective devices

The installation also requires suitable rising main pipework, delivery connections, isolation valves where appropriate, and electrical protection. The system should be designed for the expected operating pressure and the environmental conditions at the site.

How tank-level automation works

Tank-level automation normally uses a sensor or float switch to determine when the storage tank requires water.

When the water level falls to the designated low level, the control system may permit pumping if adequate solar power is available and no other protective condition prevents operation. When the tank reaches the designated high level, the controller receives a signal to stop the pump.

The exact switching arrangement varies by equipment. Some systems use separate low-level and high-level switches, while others use a multi-level sensor or an electronic level controller.

The control sequence should include suitable separation between the start and stop levels to prevent rapid cycling. The sensor positions should also allow sufficient stored water to remain available when pumping stops.

Preventing storage tank overflow

Tank overflow can waste water, damage nearby property, erode soil, and create slippery or unsafe areas. A high-level sensor can help stop pumping before water reaches the overflow point.

The upper sensor should be installed at a level that allows enough stopping margin for the system's response time and the water already moving through the delivery pipe. The required margin depends on the tank, pipework, flow rate, and control arrangement.

An overflow pipe or other suitable overflow provision may still be necessary. Automatic controls should not be treated as the only protection against overflowing.

During commissioning, the installer should test the high-level control using the manufacturer's procedure and confirm that the pump stops as intended.

Preventing borehole pump dry running

Dry running occurs when a pump operates without adequate water available for normal operation. It may happen when the borehole water level falls too low, the borehole yield is insufficient for the pumping rate, or a fault interrupts the water supply to the pump.

A suitable water-level sensor or compatible controller protection can stop the pump when water availability becomes inadequate. Some controllers also estimate dry-running conditions from changes in electrical behaviour, but detection methods and reliability vary by model.

Protection settings must be appropriate for the pump and borehole. The system should also allow a suitable recovery period before pumping resumes when water levels are low.

Dry-run protection is not a substitute for determining the sustainable borehole yield and selecting an appropriate pump.

Choosing between a float switch and an electronic sensor

A float switch typically changes its electrical state as water lifts or lowers a floating mechanism. It can be a practical option for some tank-level applications when its electrical ratings and control arrangement are suitable.

Electronic level sensors may use probes, pressure measurement, or other sensing methods. They can provide additional monitoring or control functions, depending on the equipment.

The choice depends on the tank material, water conditions, mounting arrangement, required accuracy, controller compatibility, maintenance needs, and cost.

The installer should verify that the chosen device is suitable for the water environment and intended control circuit. Direct connection to a motor circuit should only be used where the switch and equipment are explicitly designed and rated for that purpose.

Selecting the right water storage tank

Tank capacity should be based on daily water demand, expected solar pumping output, borehole yield, and the amount of water that must remain available during interruptions.

For example, a property that consumes 4,000 litres per day might consider a storage arrangement that holds approximately one day's demand. This is only an initial planning example; the appropriate capacity may be greater or smaller depending on available space, water demand patterns, pumping performance, and backup requirements.

A tank that is too small may run empty during periods of high demand. An unnecessarily large tank may increase project cost and require a stronger support structure.

The designer should also consider tank cleaning, access, inlet and outlet positions, overflow arrangements, and the structural capacity of the installation location.

Calculating the daily water storage requirement

A useful starting point is to estimate total daily consumption and compare it with the volume that can be pumped under expected conditions.

Suppose a property needs 3,500 litres per day and its solar borehole system can sustainably deliver that amount during the available pumping period. The tank must provide enough usable storage to bridge the difference between the timing of pumping and the timing of demand.

If most water is used in the evening and early morning, the system may need to store a significant proportion of the daily requirement during daylight hours.

The calculation should include any essential reserve and account for periods of reduced solar production. The storage plan must also remain consistent with the borehole's sustainable yield.

Tank foundations and structural safety

A full water tank can impose a substantial load on its supporting structure. One cubic metre of water has a mass of approximately one metric tonne, excluding the tank itself and any supporting equipment.

The foundation or elevated structure must be designed for the tank's full operating load, ground conditions, wind effects where relevant, and the structural arrangement.

A tank should not be placed on an improvised platform that has not been assessed for the expected load. Elevated tanks may require a properly engineered tower or support structure.

The installation should also provide safe access for inspection and cleaning. Electrical equipment should be located and protected so that routine tank work does not create unnecessary electrical hazards.

Installing the tank inlet and outlet

The tank inlet should deliver water without causing unnecessary splashing or damage to the tank. Where appropriate, the arrangement can be designed to reduce disturbance of sediment at the bottom.

The outlet should be sized for the required distribution flow. If several outlets or buildings draw water at the same time, the distribution system must be designed for the combined demand.

Isolation valves can help facilitate maintenance, while suitable fittings and supports reduce mechanical stress on the tank connections.

The design should include an appropriate overflow and a means of draining the tank when maintenance requires it. The tank should be installed according to the manufacturer's instructions and local plumbing requirements.

Gravity distribution versus booster pumping

Water stored at an elevated tank can flow to lower outlets by gravity. The available pressure depends mainly on the vertical difference between the water surface and the outlet, minus losses in the distribution pipework.

Gravity supply may be suitable for some homes, farms, and low-pressure uses. It may not provide adequate pressure for upper floors, certain appliances, or pressurised irrigation equipment.

A booster pump can be installed where additional pressure is required. Its selection must account for the required flow rate, delivery pressure, pipework, and control method.

The borehole pump and the booster pump perform different functions. The borehole pump lifts water from underground to the storage or delivery point, while the booster pump raises pressure within the distribution system.

Automating a booster pump

A booster pump can use pressure switches, flow controls, pressure sensors, or a compatible controller to operate according to water demand. Some systems use a pressure vessel to reduce rapid cycling.

The control equipment should be selected to suit the pump and the distribution system. Excessive starting and stopping can increase wear and may indicate an undersized pressure vessel, incorrect settings, leakage, or an unsuitable control arrangement.

Where the borehole pump fills a tank and the booster pump supplies a building, their controls should operate independently but coordinate where necessary. For example, the booster system may need protection against running when the storage tank is empty.

The installation should include appropriate electrical and hydraulic protection based on the selected equipment.

Electrical control panel requirements

An automated borehole installation may use a control panel to house switching, protective devices, interfaces, and status indicators. The design depends on whether the pump is a dedicated DC unit or an AC motor controlled by a compatible solar drive.

The panel should include the required isolation and protective functions. Its enclosure should suit the environmental conditions and protect against moisture, dust, and unauthorised access.

Wiring should be labelled clearly, and control circuits should be arranged according to the equipment manufacturer's diagrams. Protective functions must not be bypassed to make the pump run continuously.

The electrical installation should be carried out by appropriately qualified personnel and tested before the system is placed into normal service.

Integrating the tank sensor with a solar controller

Before connecting a tank sensor, verify that the controller supports the intended sensor type and electrical signal. Some controllers accept a simple contact input, while others require a specified sensor, probe arrangement, or interface.

The sensor wiring must follow the manufacturer's terminal diagram. Incorrect wiring can damage the controller or prevent the control system from stopping the pump.

The installer should confirm the expected operating sequence: when pumping is permitted, when pumping must stop, and what happens if a sensor wire breaks or a sensor becomes disconnected.

Where practical, the system should be configured so that a fault does not defeat an important protective function. The appropriate fail-safe behaviour depends on the controller design.

Automatic pumping during daylight hours

A solar pumping system can operate when sufficient solar power is available, subject to the controller's operating logic and any tank or borehole-level restrictions.

When solar output is low, the controller may reduce pump output or stop operation, depending on the equipment. Tank storage allows water to be accumulated during periods of stronger solar generation and used later.

The daily water budget should be calculated using realistic pumping conditions. The system should not assume that rated flow will be available throughout every daylight hour.

If water demand is essential during periods of low solar energy, the project may need additional storage, a suitable backup supply, or an alternative operating schedule.

What happens when the tank becomes empty?

When the tank reaches its low-level threshold, the control system may permit the borehole pump to operate again, provided the borehole water level is sufficient and the solar controller can run the pump.

The start and stop levels should be configured to avoid excessive switching. A large enough separation between levels can help prevent repeated starts caused by small changes in water level.

The system must also consider how long the pump takes to refill the tank and whether the borehole can sustain that pumping rate.

If the tank repeatedly empties before the pump can refill it, the problem may be excessive demand, insufficient pumping capacity, low solar input, a reduced borehole yield, or a fault in the pump or pipework. Changing sensor settings alone may not resolve the underlying issue.

Integrating rainwater and borehole storage

Some properties use more than one water source, such as borehole water and harvested rainwater. A combined storage arrangement can be designed, but the plumbing must prevent unintended cross-connections and protect water quality.

The system should define how each source enters storage, how overflow is handled, and which source supplies each intended use. If sources are combined, the suitability of the resulting water must be considered for the intended application.

Backflow prevention and separation requirements depend on the plumbing arrangement and applicable regulations. The design should avoid contaminating a borehole or creating an unsafe connection between supplies.

Where drinking water is involved, appropriate testing and treatment should be based on water quality results rather than assumptions about the source.

Monitoring tank levels and system faults

Monitoring can help users identify a tank that is not filling as expected, a pump that stops frequently, or a controller that reports a fault.

Basic monitoring may use visual level indicators and controller status lights. More advanced systems may use electronic displays, data logging, or remote monitoring where supported by the equipment.

Records of tank level, pumping duration, daily water use, and controller alarms can help identify changes in performance.

If the tank does not fill, the cause may be insufficient sunlight, a pump fault, a low borehole water level, a blocked pipe, a leaking connection, or a faulty sensor. Diagnosis should examine the complete system rather than assuming the tank controller is responsible.

Common automation installation mistakes

One mistake is connecting a float switch directly to a pump motor without confirming that the switch is rated and designed for the circuit. Another is using a sensor that is incompatible with the controller.

Incorrect sensor placement can also lead to overflow, excessive cycling, or insufficient usable storage. A sensor positioned too close to the tank's top may not allow enough time for pumping to stop before overflow occurs.

Other problems include omitting dry-run protection, using unsuitable outdoor enclosures, poor cable routing, and failing to test the system after installation.

The automation should be commissioned by checking each sensor and control function under the manufacturer's prescribed procedure.

Testing the automation system

Commissioning should verify the operation of the tank-level controls, borehole-level protection, controller, pump, and any booster system.

The installer should confirm that the pump stops when the tank reaches the designated high level and that it is allowed to resume when the tank reaches the appropriate lower level, subject to solar availability and borehole conditions.

Dry-run protection should be tested using the method specified by the manufacturer. The pump should not be deliberately operated without water unless the equipment's approved test procedure specifically permits a safe simulation.

The installer should inspect pipe joints, tank fittings, overflow provisions, electrical connections, and protective devices. The control sequence and any limitations should be explained to the system operator.

Maintaining tank-level controls

Float switches and sensors can become dirty, obstructed, damaged, or misaligned. Tank access arrangements should allow safe inspection without creating a fall risk or exposing workers to electrical hazards.

The sensor should be checked for free movement or correct measurement, depending on its design. Cable connections and enclosures should be inspected for damage and moisture ingress.

The control panel should be checked for fault indications, and any abnormal switching should be investigated. A pump that starts and stops frequently may have a control issue, an incorrectly placed sensor, or a problem elsewhere in the system.

Maintenance should follow the manufacturer's guidance and reflect the importance of the water supply.

Maintaining the storage tank

Storage tanks should be inspected for leaks, structural damage, secure covers, blocked outlets, and problems with the overflow arrangement. Cleaning intervals depend on the tank, water source, use, and water quality.

The tank should be protected against the entry of insects, debris, animals, and other contaminants. If the stored water is intended for drinking, appropriate hygiene, testing, and treatment requirements must be considered.

The tank foundation and supports should also be inspected for movement, cracking, corrosion, or other signs of structural deterioration.

Routine tank maintenance supports both water quality and the reliable operation of the wider pumping system.

Troubleshooting a tank that does not fill

If the storage tank does not fill, first check whether the solar array is receiving adequate sunlight and whether the controller indicates normal operation.

Next, check for relevant controller alarms, a low borehole water level, a pump fault, blocked pipework, closed valves, or leaks. The tank-level sensor and its wiring should also be examined.

Where appropriate, a qualified technician can measure electrical values, flow rate, and pumping water level to identify the limiting factor.

If the pump is working but water delivery remains low, the issue may be hydraulic rather than electrical. The pump may be operating at excessive head, the borehole may be producing less water, or the pipework may be restricting flow.

Troubleshooting a pump that will not stop

A pump that continues running when the tank is full may have a failed or incorrectly positioned sensor, damaged control wiring, incompatible control equipment, or an incorrect controller configuration.

The system should be placed in a safe condition according to the manufacturer's procedure while the fault is investigated. Do not bypass the controls or repeatedly reset the equipment without identifying the cause.

The installer should verify the sensor signal at the controller, check the wiring diagram, and confirm the intended stop logic.

An independent overflow provision is useful because an automatic control can fail. The tank and delivery arrangement should be designed so that a single sensor fault does not automatically result in uncontrolled water discharge.

Choosing a suitable automation package

The required automation package depends on the pump and controller, tank arrangement, borehole characteristics, and the consequences of water interruption.

A simple installation may require a compatible tank float switch and a suitable controller input. A more complex system may need separate high- and low-level sensors, dry-run protection, a control panel, booster pump controls, and remote monitoring.

The package should be specified from the actual equipment documentation. A list of generic components is not sufficient to guarantee compatibility.

Before purchase, identify the required control sequence and confirm how the system behaves during a sensor fault, low solar input, low borehole water level, and power interruption.

Planning the installation budget

The project budget may include the tank, supporting structure, pump, solar array, controller, sensors, control panel, cables, pipework, valves, overflow arrangements, electrical protection, labour, and commissioning.

Costs depend on the system capacity, installation height, pipe distances, site access, tank size, and automation complexity.

A useful quotation should identify which components are included, the intended operating requirements, and any additional work that may be necessary. It should also identify the protective functions included in the control system.

Comparing quotations by tank price or solar panel wattage alone can overlook important differences in the design and quality of the complete installation.

Preparing for a solar pumping automation quotation

Before requesting a quotation, gather the available borehole records, estimated daily water consumption, pump and controller details, tank capacity, tank elevation, delivery pipe route, and information about any existing level controls.

If the borehole yield or pumping water level is unknown, a suitable assessment may be necessary. The automation design should be based on a realistic water supply rather than assuming unlimited borehole output.

The installation proposal should explain the intended control sequence, how overflow and dry running are addressed, and which electrical and hydraulic protective devices are included.

Solar borehole automation and tank installation enquiries

Pro-Logic Technologies Limited works with Hydrosol Drilling Solution on borehole-related enquiries and water pumping requirements. Customers considering tank installation or automatic pumping should assess the borehole yield, required water volume, pump specifications, storage capacity, and control functions before selecting equipment.

A correctly designed arrangement can help coordinate solar pumping with water storage, but sensors and controllers must be compatible with the installed pump and electrical system.

Contact: 0723763173

Website: https://prologictecnologies.co.ke

Properly sized storage, correctly installed level controls, safe electrical protection, and documented commissioning are essential parts of a reliable automated solar borehole water supply system.