Moisture Detection In Pump Application

Oil act as a lubricant between stationary and moving segments in the mechanical hardware and ensure smooth activity of the machine. Oil seals are also referred as revolving shaft seals, which avoid leakage of contaminants like soil or liquid in the running machine.

Heavy duty submersible water pumps are widely used for water distribution in industrial & residential colonies. Some of these pumps have oil seal to protect the oil vessel from contaminants like soil, water and other impurities. If there is any wear and tear found in the seal, water or other impurities can get into the oil chamber which can further damage the motor or connected mechanical hardware. Therefore, it is imperative to detect the seal leakage and alert user for the maintenance.

Liquid level controllers along with two parallel sensing electrodes are used as moisture detector in the oil chamber. This prevents corrosion and ensure enhanced motor life, by tripping the motor instantly once water/ moisture is detected between two electrodes. The working of Liquid Level controller is based on the concept of water conductivity. Electrical conductivity is the measure of a material’s ability to allow the transport of an electric charge. Oil is a bad conductor of electricity whereas water is a good conductor of electricity, this helps to detect moisture/other impurities in the oil seal and helps to raise an alarm or trip the motor for maintenance. Liquid level controller 4421AD1 has been used, as a single level application with two electrodes.

These electrodes are immersed into oil and shows no conductivity in the idle condition. If there is any leakage in the oil seal then moisture/water will get into the Oil chamber. Hence a conductive path will be formed between electrodes. This will actuate the relay and subsequently will switch off the motor. Which will give an alert to user for maintenance and helps to detect seal leakage.