Well-chosen automation means you simply do not have to think about the pump. Water flows when you turn on the tap, the pressure in the installation stays within the set range, and if the water source temporarily runs dry, the system stops automatically and resumes operation when conditions improve. That is the whole idea behind pump control: transfer operation of the installation from the user to the electronics and keep only the result for yourself.
Our company, Dambat, has been producing and supplying automation under the IBO and IPRO brands for over two decades. In this article, we cover the entire category of water pump controllers and explain how the individual device families differ, which protective functions they perform, and how to choose the right model for a specific installation. No marketing generalities—with parameters that we actually check when making our selection.
Three tasks performed by a pump controller
Every pump controller, regardless of its class and price, handles three things at once. It is worth separating them, because only then can you see how the individual device classes differ.
- Automation. The device decides when the pump should start and stop—based on pressure, flow, or the level in the tank. This ensures convenience: you do not have to operate the installation manually.
- Pump protection. The device responds to abnormal operating conditions—lack of water, overload, phase loss—and shuts down the pump until the situation returns to normal. This ensures durability.
- Diagnostics. The display, operating-hours counter, and event log show how the system has behaved in recent weeks. This makes maintenance more convenient—especially in installations far from where you live.
Simple automatic controllers focus on the first task and partly on the second. Advanced controllers handle all three. The choice comes down to honestly assessing how valuable each of these functions is to you for a specific pump and water source. Regardless of the device class, effective pump protection starts with correctly selecting the current range, not with the number of icons on the display.
Dry running—the number-one failure that can be avoided
Water in the pump serves two roles at once: it is the pumped medium while also cooling and lubricating the mechanical seal. Maintaining this contact is the simplest way to ensure smooth, long-term operation—and that is precisely what dry-run protection handles. It acts in advance: the protection system shuts off the pump before the temperature of the gland has time to rise, and once the water returns, the system resumes normal operation. We have broken down the mechanism behind this phenomenon in our article about what pump dry running is.
Good pump protection against dry running works in two stages: first it detects the fault condition, then it disconnects the pump power supply and switches to standby mode. In the event of a lack of water, reaction time matters – the faster the protection switches off the pump, the more gently the entire episode affects the seal and bearings. It is worth understanding the difference: the factory thermal protection in the winding responds to the effect, namely temperature, while an external controller responds to the cause, namely the lack of medium. That is why dry running must be addressed at both levels simultaneously.
Our range includes three different methods of detecting a lack of water, and it is worth understanding the difference between them. Each handles dry running differently, and each has different installation requirements.
Pressure-flow protections
Flow-based protections simultaneously analyse the pressure and presence of flow in the discharge pipeline, meaning two quantities measured directly on the discharge side. If the pump is running but there is no flow, the device identifies this as dry running. This is how most pressure-booster controllers operate, including PC-24 and SK-30. Advantage: no additional wiring in the well. Limitation: the method requires clean water without mechanical impurities, because the sensor is immersed in the medium. Such flow-based protections work well in domestic installations, but less well in intakes supplying sandy water.
Probes and liquid level sensor
The second approach is direct measurement in the well. A liquid level sensor – a conductivity probe or float – provides the controller with information about the fill level. The M21 controller is supplied with three measuring probes with one-metre cables specifically for this purpose. This is the most unambiguous method: it responds to the actual water level, rather than a hydraulic derivative. However, it requires access to the well and the probes to be suspended correctly, as discussed below. A properly selected liquid level sensor allows the system to be stopped before the water level in the well drops to the suction port, rather than when the pump has already started drawing in air.
Current consumption monitoring
The third approach is analyzing the motor current. A pump operating without water draws significantly less current than one under hydraulic load—this phenomenon is used by IPRO controllers in the IPC series, whose non-contact inductive technology detects dry running without installing a probe in a deep, narrow well. PROTO-X works in a similar way. The method is non-invasive, but requires correct calibration for the specific motor. In return, pump operation monitoring takes place entirely on the electrical side, without any element submerged in water.
In practice, the highest level of pump safety is provided by combining two methods. The M21 controller uses dual protection against dry running—it simultaneously analyzes the signal from the probes and the current draw of the operating pump. If you want to effectively protect submersible pumps operating in wells with variable output, this is the option we recommend most often.
IBO pressure controllers – PC and IQ PRESS series
This is the largest group in the category and the starting point for most domestic installations. Each of these devices takes over the functions of a pressure switch, dry-run protection and—in some models—a check valve, reducing the number of components on the pipeline. As a result, one pump controller replaces three separate components, and pump operation in a domestic installation proceeds without user intervention.
PC-24 operates one single-phase pump up to 2.2 kW at a supply voltage of 220–240 V AC and a maximum current of 16 A. It operates in two modes: in the first, you set only the switch-on pressure; in the second, you also set the switch-off pressure—this variant requires a diaphragm tank. The adjustment range is 0.8–6.7 bar for switch-on pressure and up to 7.0 bar for switch-off pressure; the maximum pressure is 10 bar, and the permitted water temperature is 60°C. Every 24 hours, the device performs a ten-second test start-up to prevent the impeller from becoming blocked during extended periods of disuse. When the water supply returns, an automatic restart is performed, so the system resumes operation without user intervention.
PC-34 extends this logic with a third operating mode and a built-in check valve. PC-30P applies the same concept to pumps of up to 3 kW—we choose it where the pump power supply supports a more powerful single-phase motor. PC-99 adds a pressure reducer, useful wherever the installation downstream of the pump cannot withstand high values; we explored this topic further in our article on how to protect an installation from excessive pressure.
IQ PRESS stands out by allowing direct control of one or two single-phase pumps simultaneously—it is a pump control device for systems requiring backup or alternating operation without installing a separate control cabinet. The similarly designed MULTI PRESS 2 by IPRO and PRO 1 can operate synchronously with a second controller operating an auxiliary pump.
SK-30 and WATER-PASS – controllers with a pressure gauge and check valve
SK-30 is designed to automatically adjust to the installation during initial startup and remember the operating pressure, which can later be adjusted in increments of 0.1–0.2 bar. A pressure gauge and a check valve are housed in the same enclosure. It supports 0.1–2.2 kW pumps with a 100–240 V AC power supply, allows water pressure of up to 10 bar, and—unlike its competitors—supports medium temperatures of up to 100°C. In the event of a water shortage, it disconnects the pump after approximately 10 seconds and retries every hour; a manual restart is also available using the AUTO/RESET button.
The IPRO WATER-PASS 2 goes one step further by integrating a one-liter tank that reduces water hammer. The factory-set activation pressure is 1.5 bar, the maximum operating pressure is 15 bar, and dry-run protection responds after 8 seconds. The printed circuit board is coated with epoxy resin, which is important in rooms with high humidity. Installation note: an additional diaphragm tank should not be installed with WATER-PASS 2 because the device has its own. However, a larger one can be installed if you need to increase the buffer in the future.
M-series controllers – when you need an operating history
The IBO M range is in a different functional league. Here, the device not only controls pump operation, but also keeps an installation log. It is an equipment unit for operating pumps in places where not only activation itself matters, but also knowing what has been happening in the system over the past few weeks.
M121 is the basic model for single-phase pumps rated at 0.37–2.2 kW: automatic activation, calibration for the specific pump, and a complete set of protections. M21 adds a cumulative operating-time counter and a history of the last five faults in which the protection functions were triggered. This difference may seem minor, but in practice it changes how servicing is performed: instead of guessing what happened, you read the record on the display.
The three-phase versions are M131 and M31, available for 0.75–4 kW and 5.5–7.5 kW ranges. They monitor the power supply and motor operating parameters, while dry-run protection works even without installing probes in the well. They receive the control signal from probes, float switches, or a pressure switch, so you can adapt them to the existing configuration. In tank systems, the controller controls pump operation based on the level in the target tank rather than the pressure in the pipeline. M21 operates in temperatures from −25°C to +55°C and has an IP22 protection rating – it is designed for installation in a control cabinet, not on the wall of an unheated utility building.
IPRO IPC controllers – one and two pumps
The IPC series is based on a single-chip microcomputer and was designed to control pump operation in technological installations where pump operation must remain maintenance-free throughout the season. Contactless inductive technology provides dry-run protection without a probe, which is important in deep, narrow wells where sensor cabling is troublesome. Applications include centrifugal, submersible, multistage, deep-well, sewage, booster, and in-line pumps.
There are several variants, differing mainly in power and the number of pumps they support. For one pump: IPC 122M (0.37–2.2 kW, 230 V), IPC 140M (0.75–4 kW, 230 V), and IPC 175T (1.1–7.5 kW, 400 V). For two pumps: IPC 240T and IPC 275T.
The controller controls pump operation according to the selected configuration, and four scenarios are available in dual-pump versions: one pump operates while the other remains on standby; both operate alternately; if one fails, the other starts automatically; at a high water level, both start simultaneously. Alternating pump operation balances wear on both units: the rotation time can be set from 0 to 480 minutes, and every 15 days the controller runs an anti-corrosion cycle. The dry-run response time can be adjusted from 0.1 seconds to 3 minutes—a parameter tailored to the inertia of the specific system.
PROTO-X – the simplest protection for single-phase pumps
Not every installation requires a programmable controller. PROTO-X is an adapter-style protection device: plug it between the mains socket and the 230 V pump plug, and that’s it. It protects against voltage fluctuations, dry running, and rotor blockage. The entire pump power supply passes through the measuring module, so it responds independently of what is happening in the pipeline. The basic version operates in the 3–8 A range, while PROTO-X PLUS operates in the 6–10 A range. When the current threshold is exceeded, the protection device switches off the pump and indicates this with a red LED, so it is immediately clear that the system has responded.
This is a device for controlling pumps that are already installed, where rebuilding the control system is not an option. It provides effective pump protection in two typical situations, and installation takes only a moment, requiring neither tools nor interference with the pipeline.
Automation for submersible pumps—a special case
A drilled well has its own specific characteristics, which is why we treat automation selection for submersible pumps separately. The pump operates several dozen meters underground, while the water level changes seasonally and throughout the day. Maintaining constant hydraulic contact with the medium directly translates into submersible pump durability, and properly selected automation monitors this without user intervention—even when no one is on site.
To effectively protect submersible pumps, you need information about where the water level is during extraction, not at rest. During intensive withdrawal, the dynamic water level drops, and it determines the safety limit. If you observe a drop in pump output during peak season, it most often indicates that the well’s yield cannot keep up with demand—not that the pump has worn out.
In practice, we use two scenarios. When the well allows sensors to be suspended, a liquid level sensor connected to an M21 or M31 controller provides a clear picture of the situation and allows the motor to be stopped before the water level falls to the inlet. When the borehole is deep and narrow, we use current detection in IPC controllers—in this way, submersible pumps can be protected without any cabling in the well. Both approaches serve the same purpose: pump operation control should keep the system within a safe range, rather than merely record what has happened in it.
It is also worth remembering the electrical installation. At great depths, the power cable can be several dozen meters long, and the voltage drop along this route lowers the actual rated supply voltage at the motor terminals—which in turn distorts the controller’s current readings. We have compiled the installation guidelines in our submersible pump installation guide. It is precisely in this group of devices that an increased level of pump safety provides the greatest freedom—the installation can operate seasonally without constant supervision.
Parameters we compare when selecting
When comparing offers, it is worth looking at the same fields in the product data sheets. Below are three representative designs from our range.
| Parameters | PC-24 (IBO) | SK-30 (IBO) | WATER-PASS 2 (IPRO) |
|---|---|---|---|
| Rated supply voltage | 220–240 V AC, 50/60 Hz | 100–240 V AC, 50/60 Hz | 100–260 V, 50/60 Hz |
| Max. power of the controlled pump | 2.2 kW | 0.1–2.2 kW | 2.2 kW |
| Max. current | 16 A | 30 A | 12 A |
| Max. operating pressure | 10 bar | 10 bar | 15 bar |
| Max. liquid temperature | 60°C | 100°C | 80°C |
| Degree of protection | IP65 | IP65 | IP65 |
| Additional equipment | Pressure sensor, display | Pressure gauge, check valve | 1 L tank, check valve |
We check two values on the motor side separately: the rated continuous current shown on the nameplate and the power. The controller must cover both with a safety margin, because the starting current of a single-phase motor can be several times higher than its operating current. If the pump's rated continuous current is close to the upper limit of the device's range, we choose a model one class higher.
How to select a controller – decision sequence
- Pump type and location. Automation is selected differently for submersible well pumps in a drilled well, for a surface pump located in a building, and for a submersible pump in a pumping station.
- Power supply. 230 V or 400 V. For three-phase power, go straight to M131, M31, IPC T-series models, or IBOPRESS 30.
- Motor power and rated current. Read from the nameplate, not the catalog – different versions may vary.
- Water shortage detection method. Do you have access to the water intake and can you suspend probes, or do you need a non-invasive method?
- Required additional functions. Alternating operation of two pumps, history recording, level control in the target tank, remote signaling.
Our installation converters are helpful when estimating parameters, including the pressure unit converter and the cable cross-section selection table – on long runs in a well, the voltage drop can distort the controller's current readings.
Controller, pressure switch, or inverter
These three solutions are often confused, although they perform different tasks.
A classic pressure switch, that is, an electromechanical device with a diaphragm and contacts, simply closes and opens the circuit at preset thresholds. Models such as the PC-9 and the three-phase LCI-2 are adjusted with two screws and contain no electronics—their strengths are simplicity and durability, while their natural limitation is the lack of protective functions. We have gathered the full range in the pressure switches category, while we also offer separate categories for pressure controllers and DIG-IBO 1.
An electronic controller performs the same functions as a pressure switch, while adding protection and diagnostics—so that pump operation monitoring also covers electrical parameters, not just pressure. A frequency inverter, on the other hand, smoothly regulates the motor's rotational speed, maintaining constant pressure instead of cyclically switching the pump on and off, so pump operation takes place without sudden changes in the system. It is worth remembering that in our industry, inverter refers to a device that regulates the pump's operating conditions, not a converter used in a photovoltaic installation. We describe the differences in our articles about smart pumps with frequency inverters and IBO and IPRO frequency inverters; you can find the range in the frequency inverters and accessories category.
For larger facilities, control is transferred to a control cabinet—in that case, we use SPS and SPD series control cabinets, supplemented with ZSP level signaling sets. We have grouped the entire automation category under control and protection.
Installation of pressure switches and controllers
Correct installation of pressure switches begins with choosing a location on the pipeline. The device is installed on the discharge line, just after the pump and before the branch leading to the draw-off points—so that it measures the water pressure throughout the entire system rather than in a single branch. With this setup, the device responds to every draw-off, regardless of which point is opened.
The second rule concerns the operating position. SK-30 and WATER-PASS 2 operate exclusively in a vertical position, while PC-24 allows vertical and horizontal installation. The connections on every controller have flow-direction arrows—following them guarantees correct flow detection during the first start-up. For larger sets, installation of pressure switches is planned together with the pressure vessel and check valve to avoid duplicating functions.
The third point concerns the environment. IP65 protection allows operation in a damp room, while IP22 does not. M-series controllers are designed for installation in a cabinet, which is worth taking into account when planning the distribution board. With probes, the clearance rule applies: the activation point should be clearly above the pump inlet so that the water level does not fall below the safe limit before the system can respond. Correct installation of pressure switches and probes is, in practice, half of the entire system’s reliability.
Six things worth checking before start-up
The list below is a quick checklist before the first start-up. Going through it takes a few minutes and gives you confidence that the system will start as planned.
- Clean water before the controller. PC-24, SK-30 and similar designs operate with water free of mechanical impurities. If the water intake supplies sandy water or water with an elevated iron content, a filter installed before the controller will provide the sensor with suitable measuring conditions.
- Pressure vessel for two-threshold operation. Operation at two pressure thresholds runs smoothly when the system includes a tank—it smooths out the start-up cycles. We described the correct pressure setting in the vessel in a separate article, while you select the tanks according to the system flow rate.
- Clearance above the suction connection. Hang the probe so that it detects the falling water level in advance. A clearance of several dozen centimetres is entirely sufficient and gives the system time to respond calmly.
- Flow direction and operating position. The arrows on the connections indicate the correct connection direction. SK-30 and WATER-PASS 2 operate in a vertical position, while PC-24 allows both vertical and horizontal installation—this is worth checking before assembling the system.
- Protection rating suited to the location. Devices with IP65 operate in damp rooms, while IP22 models – such as the M21 – are intended for installation in a cabinet. Simply match the enclosure rating to the conditions in the room.
- One device per circuit. An automatic pressure controller with its own check valve fully handles the section on its own – an additional pressure switch on the same branch is not needed, and omitting it simplifies the settings.
Documentation and support
You will find connection diagrams, factory settings, and error codes in the manuals: separately for the IBO brand and the IPRO brand. IBO products are covered by a 24-month manufacturer’s warranty, while warranty and post-warranty service is provided by our service department. If you are unsure which model will operate your pump, contact us – provide the pump type, power, power supply, and water intake method. We have explained the terms that appear in the product data sheets in the glossary of hydraulic terms, and the operating principle of the entire system in the article about how a pressure booster system works.
FAQ – water pump controllers
Does the controller replace the pressure switch and pressure vessel?
Pressure switch – yes, electronic automatic controllers fully take over the functions of a pressure switch. Pressure vessel – it depends on the model and operating mode. The SK-30 works correctly with a small 5-liter vessel, WATER-PASS 2 has its own 1 L tank and does not require an additional one, while the PC-24 requires a vessel in two-threshold mode.
What happens after the dry-run protection is triggered?
After dry-run protection is triggered, most of our devices perform an automatic restart. In the event of a lack of water, the SK-30 disconnects the pump after approximately 10 seconds and retries every hour, WATER-PASS 2 responds after 8 seconds, while the response time in IPC controllers can be set from 0.1 seconds to 3 minutes. If the water does not return, the protection switches the pump off again and the cycle repeats; a manual restart using the button is also available.
Will the controller improve the performance of my pump?
No. Pump performance results from its hydraulic characteristics and the resistance of the installation—automation does not change it. The controller does, however, affect the service life of the submersible pump and the convenience of using the installation. If you notice a drop in pump performance, it is worth checking the hydraulic system and the water-table level in the well—that is usually where the explanation lies.
Which controller is suitable for two pumps operating alternately?
IPC 240M, IPC 240T, and IPC 275T from IPRO are designed for two-pump systems. They support alternating operation with an adjustable rotation time of 0–480 minutes, automatic takeover when one pump fails, and simultaneous startup of both pumps when the level is high. A simpler alternative for two single-phase pumps is IQ PRESS.
Can a pump be protected without rebuilding the installation?
Yes—that is what PROTO-X is designed for. It is connected between the socket and the plug of a 230 V pump, without modifying the pipeline. The basic version supports a range of 3–8 A, while PROTO-X PLUS supports 6–10 A. It is the simplest way to add pump protection and a higher level of pump safety to an existing system—complete pump protection without a single cut in the pipeline.
A probe in the well or current detection?
A probe provides an unambiguous reading but requires access to the water intake and correct suspension. Current detection requires nothing in the well, but it must be calibrated for the specific motor. In difficult wells—deep, narrow, or with limited access—we choose current detection, for example in IPC controllers. It can protect submersible pumps even when the water table is inaccessible to the probe, and it genuinely extends the service life of the submersible pump.
Where should a pressure gauge be installed in a system with a controller?
The SK-30 has a built-in pressure gauge. In other setups, it is installed on the discharge pipeline in a location visible from the operating position—without a pressure reading, diagnosing the system is guesswork. We discuss this in more detail in the article about pressure gauges and measuring water pressure.
Do the controllers work with float switches?
Yes. M-series controllers receive signals from probes, float switches, or a pressure switch, so they fit into an existing setup. You can find the equipment in the float switches category, and we describe the operating principle in the article about a pump with a float switch.
