How Do Float Switches Work (Diagram & Working Principle)

Float Switch Working Principle

If you are searching for “float switch working principle” or “how does a float switch work” this post should help.

How Old Float Switches Work

How Do Float Switches Work Diagram

Older Float Switches work by opening and closing circuits (dry contacts) as water levels rise and fall. Typical float switches are normally resting in the closed position, meaning the circuit is incomplete and no electricity is passing through the wires yet.

Old Float Switch Working Principle

Once the water level drops below a predetermined point, the circuit completes itself and sends electricity through the completed circuit to trigger an alarm.

How does the electricity pass through the circuit? The electricity passes through, what are called, magnetic reed switches. Once the water does drop low enough, the reed switches come in contact with each other and complete the circuit, allowing electricity to be passed through them and turn on the alarm. Once the water gets high enough again, the switches break apart and disconnect the circuit.

The Magnetic Reeds Open & Close To Control Water Levels

The magnetic reeds are sealed in a stainless steel or plastic stem. The magnetized reed switches move and down as the water level increases and decreases and are set to come together and break apart at different heights that you specify during installation.

The problem with the way these old float switches work is that they can deteriorate due to poor water quality and electricity passing through them. That’s why Water Level Controls created their own float switch replacement that uses sensing probes to gauge water levels instead of floats.

Float Valves

Other cooling tower operators typically used float valves instead of sensor rods for automatic control of water levels. Float valves use a floating mechanism and arm to gauge water levels and turn on and off pumps. These types of float switches could only do 1 or 2 operations unlike new float switches that can be programmed to handle many automatic operations.

How New Float Switches Work

Float Switch Diagram - How Do Float Switches Work

Water Level Control’s float switches work by using probes instead of float switches.

The sensor probes actually act as their own sensors and do not pass electricity through the probes which keeps them from fouling, degrading and deteriorating. Also, all of the electronics are built into the head so you can connect directly to your control panel. Once the water level is detected by one of the sensors, this causes one of six alarms to be triggered (High Alarm, Low Alarm, Fill Start, Fill Stop, etc). Depending on the type of float switch you have, there can be single point alarm or a multi point alarm that is triggered.How Do Float Switches Work

Single Point & Multi Point Float Switches

Single point and multipoint float switches allow you more control of your storage tank filling mechanisms and will last 5 times longer than traditional float switches.

How Single Point Float Switches Work

Single Point Float Switch Working Principle

Single point float switches work with 3 sensor rods (Reference, Start & Stop) that work in conjunction to turn on and off your water pump automatically. This helps keep water levels at a consistent level.

How Multi Point Float Switches Work

Multi Point Float Switches Working Principle

In Multi-point float switches, there are 4-6 sensor rods (High alarm, fill 1 stop, fill 1 start, fill 1/fill 2 stop, fill 2 start, low alarm, reference). These rods can programmed to do multiple tasks such as stop water levels once they reach a predetermined point and start filling water once its drops below a certain level.

The most basic way to explain this is; the sensor probes stick down in the water to detect water levels at different heights, depending on the height of the water, the probes all have different tasks they perform. If the water level is too low, it sets off the low water alarm, if the water is too high, it sets off the high level alarm etc.

Buy Cooling Tower Float Valves

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Cooling Tower Problems & Solutions

Cooling Tower Problems & Solutions Phoenix AZ

Are you searching for “Cooling Tower Problems & Solutions” while looking for a way to fix your cooling tower issues? If so, this article should help! We have also included links for parts you might need to repair your cooling towers.

This article is designed to help you figure out what is going on and understand the ways that cooling tower maintenance companies help get you back on track.

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Cooling Tower Problems


There are four major water treatment issues that facilities have to maintain and monitor the control of, including scale, corrosion, microbial contamination and fouling for optimal system reliability and operational efficiency. The results include experiencing lower operating and equipment costs for the cooling systems, leading to less unscheduled downtime because of problems related to water.

Here is a list of the most common cooling tower problems and throughout the industry and the solutions.

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Cooling Tower Corrosion Problem


The environment of cooling systems is ideal for corrosion. For instance, a closed loop system does not lose much water, and they frequently get ignored in the maintenance process which makes them more susceptible for corrosion issues. Although, this neglect often leads to leaks and repairs that can be costly from cooling system leading to potential damages to other systems and locations.

Cooling Tower Corrosion Solution: The solution to cooling tower corrosion is making sure your cooling tower coatings are applied correctly and still working properly.

Cooling Tower Scale Problem


The heat exchange surface helps the cooling system’s main function perform, but can be responsible for scale production. When high temperatures lower solubility of specific species within water, like calcium, which can form deposits on the heat exchange surface, which causes the scale. This acts like an insulator that lowers the tower efficiency and heat dispersal, leading to increased costs and consumption.

Cooling Tower Scale Solution: Regular cooling tower cleaning and maintenance will help keep scale out of your cooling towers which will increase your cooling towers efficiency.

Cooling Tower Fouling Problem


This is a common issue which is caused from the ‘three-d’s’, dust, dirt, debris. Although, it can be caused from other contaminants within the system too, like microbiological growth or corrosion products. Fouling can have a dramatic effect on reducing system efficiency while increasing operational costs and energy usage.

Cooling Tower Fouling Solution: Fouling usually takes place in metal that is not protected or low quality. Stainless steel is used to prevent corrosion in float switches and other cooling tower components.

Water Level Control Problem 


Another major problem with cooling towers is having to replace water level controls every 3 years. Replacing your float switches can be costly.

Water Level Control Solution: That’s why Cooling Tower Products works directly with the top selling water level control manufacturers in the industry to provide you with

Cooling Tower Biological Contamination


The warm water and rich nutrient supply of a cooling system is the ideal environment for bacteria growth and various other forms of biological growth. However, the true main problem is with microbial growth resulting in biofilm, which becomes an issue with the ability of harming the system operations. It has four to five times the insulation property that calcium carbonate scale has, which can lead to the energy costs rapidly going up while promoting corrosion and scale.

Cooling Tower Contamination Solution: Regular cooling tower cleaning and maintenance will help keep scale out of your cooling towers which will increase your cooling towers efficiency.

Cooling Tower Solutions


Start minimizing system stress while maximizing operation performance by selecting the correct chemical treatment program. With the four major water quality issues, there is not a single issue that stands out as more important because any of them can lead to the next.

To make things more complex, chemistry and water quality can vary based on location, so there’s not a single universal treatment program either. Rather, the first step is to determine a chemical treatment program as the start for an efficient and reliable cooling system for balancing management of each of the four main quality issues.

Cooling Tower Maintenance Matters


Having great cooling system maintenance is great business, and it all starts with having a good water treatment program. The treatment program and water quality of the cooling system have a direct effect on efficiency, reliability, and operating costs of institutional or industrial cooling systems.

Path to Reliability

No matter the fact of a universal treatment not existing, the path for a reliable cooling system remains the same, using correct and effective water treatments. Using a program that is effective, facilities are able to control problems which and lead to even more unexpected expenses and higher operating costs.

Pay Now or Pay Later

Basically, spending the time for proper prevention will become a better investment compare to replacement or repair. By ensuring common cooling system issues are addressed with frequent maintenance, operators are able to avoid potential crippling effects that can occur with the processes of shutting down system supports. This is why having great cooling system maintenance and water quality is good business.

Cooling Tower Services In Phoenix, Arizona


If you need some help with your cooling tower service and maintenance in the Phoenix area, Cooling Tower Products has you covered. With the best technicians, quality parts, and the highest standards customer satisfaction we will help you find and solve all of your cooling tower problems. Doing so will decrease the energy needed to operate your cooling tower and save you money on the electricity bill. Our Cooling Tower ServicesCooling Tower Maintenance, Cooling Tower Repair, Cooling Tower Rebuilding, Cooling Tower Refurbishment Services and New Cooling Tower Construction.

We Sell Cooling Tower Parts & Ship Nationwide


Looking for cooling tower replacement partsDrift Eliminators, Counter Flow Fill Media, Cross Flow Fill Media, Air Intake Louvers, Cooling Tower Coatings, Water Level Controls, Evaporative Cooling Media and Cooling Tower Nozzles.


Natural Drafting Cooling Towers Explained

Natural Drafting Cooling Towers Explained

Natural draft cooling towers are the correct option for larger power plants.

The operation of the natural draft cooling works with a stack of effect, causing hot air within the tower to increase (natural draft). The main use for natural draft cooling towers is within the electrical energy industry, however, it can be utilized for various other industrial objects too. These towers let the cooling of higher water volumes while being designed for metal and concrete structures.

The following advantages are provided:

  • Environmentally friendly
  • Power saving, air flow is not induced with power consumption
  • Operation safety
  • No fan, no mechanical noise
  • Limited plot region
  • No re-circulation of rejected plume at higher levels
  • High longevity, commonly
  • Limited maintenance
  • 8 to 16-year payback period


Regions of application

Among industries and power plants that have an unlimited flow of cooling water, the largest cooling tower using natural draft, that we have created to date has a quantity flow rate of 216,000 m3/h.

Key Features

When it comes to cooling, the air stream volume required is produced exclusively by the stack effect. Natural draft cooling towers’ unique economic advantage comes from the very low electric energy requirements. There are minimal operating expenses.

It is an economical solution for higher cooling loads and depreciation in longer periods.

The distance between the air inlet and outlet of the cooling tower avoids re-circulation from warm air which may result in decreased performance.

Almost a full lack of moving parts provides minimal maintenance and higher operating reliability requirements.

Due to the warm air outlet’s height, the surrounding region remains unaffected by the cooling system effects.

Comparison of cold water temperatures and cell cooling towers

Natural draft cooling towers’ cooling air flow volume depends directly on localized conditions such as barometric pressure and air temperature. The air volume stream of cell cooling towers are created using constant and fans. Therefore, varying cooling tower characteristics are created from various local conditions. Under the design, natural draft cooling towers provide cold water temperatures that are more favorable compared to cell cooling towers, and vice versa.

Natural draft cooling tower winter operations

In comparison with mechanical draft cooling towers, cooling air stream volumes of natural draft cooling towers is not controllable directly. With a winter operation, the temperature outside, as well as the thermal load can provide different results. Thus, the control elements that follow can be deployed: zone control, such as disconnecting the individual cooling zones, as well as winter control, such as developing air inlet hot water bypasses.

Winter operation

The construction of the water distribution system is designed to handle about 120% overload. Thus, in the event of an isolated cool zone, extra water is routed by the bypass into the cold water basin, directly. The process utilizes diversion and does not use fittings. There are no problems with the winter start-up.


There are a couple of disadvantages to these monolithic cooling towers. Some types of industry and power production necessitate natural draft cooling towers. Companies considering installing cooling towers for industrial or commercial purposes should weigh the load they will have, and choose the cooling tower that best fits their needs and location.

  • Increased investment expenses. Due to the size and technology there is a significant difference in the budget necessary to build a natural draft cooling tower.
  • A larger size which may lead to challenges with region aesthetics and the requirements of larger regions needing tower installation.

Phoenix Cooling Tower Installation & Repair

If you need to install, service, or have a cooling tower repaired we have the parts, techs, and knowledge to repair any cooling tower in the greater Phoenix area. Don’t wait for your cooling tower to be drawing excessive electricity, get it serviced today. To schedule your maintenance call 1-800-733-1584.

Cooling Tower Vibration Analysis | Vibration Cut-off Switch

cooling tower vibration analysis Vibration Cut-off Switch

Vibration is a common problem in cooling towers and other types of mechanical or industrial equipment.

Cooling tower vibration limits?

Machines that require moving parts are built to withstand a specific limit of vibration without losing their reliability or performance. Issues occur when vibration exceed manufacturer limits, usually caused by abnormal situations.

Cooling towers use fans, drive-shafts, and motors which operate 24 hours a day, every day of the year. Vibration in cooling towers must be addressed quickly to avoid long shut down times, and avoid severely damaging major components in the cooling tower (due to the fact that the fans and cylinders are so close together).

There are many sources of cooling tower vibration:

  • Unbalanced cooling tower fan blade
  • Uneven pitch of fan blade
  • Worn shaft, couplings, or drive-shaft inserts
  • Worn mechanical equipment bearings (fan-shaft bearings, motor, gear reducer)
  • Gear tolerances inadequate in gear boxes
  • Gearbox is damaged
  • Structural deterioration of mechanical equipment
  • Worn belts in belt driven equipment
  • Misalignment of mechanical equipment, pulleys/sheaves or drive-shafts
  • Fasteners loose in mechanical equipment and its supporting structure

Can vibration damage your cooling towers?

Sustained period of vibration in cooling towers can cause severe damage, including damaging mechanical equipment (For example – fan cylinder being hit by fan blade tips, damaging both fan blades and cylinder) and impacting surrounding installations. In less common situations, vibrations in cooling towers can cause discomfort to people in the vicinity and the surrounding structures.

The best way to avoid abnormal vibration and mechanical failure is to install a vibration cut-off switch.

What is a vibration cut-off switch?

The cooling tower part/accessory will shut down the evaporative cooling equipment of cooling tower when vibration levels exceed manufacturer specification limits.

It is wise to test your vibration switches periodically to make sure they are operating properly. Another great practice is to install data loggers for your vibration switch, the data logger will help monitor the vibration and help you implement better preventative actions as needed.