Submersible motors are installed in pumps, which are used for removing water from one place to another. These motors are needed for agriculture, mining, wastewater management and the extraction of natural oil and gas. These motors are specially designed to function efficiently when fully submerged under water or other fluids. Hence, submersible motors are more reliable in working under very high pressure and in other adverse situations. Still, these motors are known for their high durability despite the least need for maintenance.
The following factors are the reasons for the high reliability of submersible motors, which are the result of engineering brilliance and innovative designs.
Sturdy Materials
Usually, submersible motors are made of stainless steel, cast iron, and special alloys, which are resistant to corrosion. These materials can endure high pressure of fluids and a high salinity level. Hence, these motors can be safely used in all types of environments for many years.
Sealed Structure
A submersible motor is protected by placing it in a sealed casing, which is waterproof. Thus, water or other fluids cannot come in direct contact with the motor. Mechanical seals, like O-rings and gaskets, prevent the entry of mud, chemicals, and other debris into the motor casing. Thus, the internal parts of the motor remain protected from the abrasion caused by various particles.
Fast Cooling System
The submersible motor is designed to be cooled automatically by the water or fluid surrounding it. Thus, there is no risk of overheating of the motor even if it works continuously for hours. Consequently, the loss of energy caused by overheating is much less when running this motor. Moreover, some motors are provided with a thermal protection system to shut down the operation if the motor becomes too hot.
Priming or Alignment is not Needed
The motor unit is integrated in a submersible pump, which can be directly placed under water. So, there is no need for priming, which is a time-consuming process and also creates errors in other centrifugal pumps. Also, the alignment of the shaft of the motor and the pump is not required here. Therefore, the risk of mechanical faults is minimized in a submersible pump, and its smooth operation can be expected.
Wiring Sealed Securely
Copper coils used for creating electromagnetic fields are protected in oil-filled enclosures or embedded in resin. Thus, there is no risk of short-circuit or corrosion of copper wires, as water particles cannot come in contact with these wires. Some submersible motors are provided with double layers of insulation or thick enamel coating to prevent electrical failure during the operation of the pumps.
Designed for Low Vibration
If the motor vibrates too much while running, its longevity reduces gradually. Frequent vibration causes too much damage to the bearings and shaft, leading to failure in operation. Hence, submersible motors are designed to rotate smoothly without vibrating, which increases the durability of the bearing and minimizes the mechanical deformation of motor parts. When the motor is submerged, vibration and noise are further reduced by the surrounding fluid.
Proper Lubrication of Bearings
Every submersible motor is provided with specially designed bearings, which are heavy-duty and well-lubricated. These bearings can function for several hours below water without any need for relubrication with oil. Some motors also contain self-lubricating and self-aligning bearings. So, these bearings help in withstanding the heavy pressure of fluids. Moreover, the sealing systems of the shaft protect bearings from abrasion caused by debris present in the water.
Resistant to Corrosion
The metal body of a submersible motor is likely to be damaged due to corrosion when placed under water for hours. Moreover, working in salty water, wastewater from sewage, and chemicals present in water can cause harm to the motor of a submersible pump. Hence, every submersible motor is made of corrosion-resistant materials, which are not affected by oxidation, chemical reactions, or rust. The shaft, rotators, and fasteners of the motor are made of high-quality stainless steel. The cables or windings are made of insulating materials that are non-corrosive too. The motor body is protected with ceramic or epoxy coatings to make it safe from all possibilities of damage.
Requirement of Minimum Maintenance
A submersible motor is designed as a compact unit, without any external movable parts, like belts or pulleys. Thus, there is no need to replace fast worn-out parts in this motor. Since this motor is weatherproof, self-aligned, and self-lubricated, there is no need to check its health at regular intervals. So, submersible motors can function for a long time in deep wells, water pumping stations, and for sewage lifting, without any maintenance headache.
Provision of Extra Protection
Now, many submersible motors are provided with more protective features. These motors can prevent damage caused by high electrical current or mechanical blockages in the submersible pumps. When the entire bulk of water is pumped out, the motor stops automatically to prevent overheating, as there is no more water around it for natural cooling. The motor body is protected from sudden voltage spikes caused by lightning or a fault in the electrical circuit. The motor is fitted with sensors to alert to excessively high temperature, leakage, and too frequent vibrations. Thus, operators can stop the pump before any further damage occurs, reducing the need to repair the motor.
The Best Performance
Submersible motors can be used in remote areas for irrigation or water management, without any breakdown or need for repair. These motors last for decades while moving huge quantities of groundwater or sewage water efficiently. Usually, a submersible motor lasts for 10 – 20 years, making it highly cost-effective for owners. In urban areas, these motors are needed mainly for removing sewage water and accumulated rainwater, even in critical situations.
Wrapping Up
Therefore, a submersible motor is a highly reliable machine, which is useful everywhere for different reasons. Its efficiency and fast working ability made it more popular in both rural and urban areas, to solve various water-related problems. Submersible motors are most reliable among all types of electrical motors available for pumps.