Wednesday, August 30, 2006
Buy quality motors and sleep peacefully
Fed up of the noise from your or neighbour's water pump? Has it destroyed your sleep? If yes, this article is for you.
Some pumps create a huge noise when switched on to ensure 24-hour running water in your taps. The pump is music to your ears when it is new; but it gets noisier as it gets older. "My neighbour starts his motor at 1 a.m. and destroys my sleep," says Ravi of J.P. Nagar, 6th Phase. Manjunath S., another resident of the area, says that the water pump in his house is fixed near the window. "It is very old and when it is switched on, its sounds as though a train is moving."
The cause
Low quality and old bearings, problems in a part in the motor, problems in shaft, improper placement of pumps, low quality motors and exposure to rain are among the reasons for the noise. And there are ways of tackling these problems.
Low quality bearings are the major cause. Because the bearings get worn out fast, the noise from the pumps increases. Wear and tear in the bearings is also caused due to the exposure of the pumps to rain. When water enters the motor, the bearings and other parts get rusted, leading to faster wear-out. The result is unbearable noise. A motor should be given a proper covering and protection from rainwater. The shaft gets heated when the bearings run continuously and this can change the alignment of the shaft. And in some instances the shaft can also gets worn out, resulting in noise. The shaft also gets damaged due to the worn-out bearings.
Impeller is the component which pumps water in the motor and it is supported by a lock nut. If this lock nut is loose, the motor produces sound. Switching it on many times without letting it cool down can lead to the loosening of the lock nut, says Subramani of Rajarajeshwari Engineering Works. He is a technician who repairs motors. And fixing the motors in congested places means there is no space for the sound to escape freely. House owners often fix the water pump under the staircase, which is wrong. Fixing it crossly will also generate nois, says Sharieff, who sells water pumps.
The staircase may create an echo and worsen the situation, says S. Sampathraman, Chairman and Managing Director of DPK Engineers Pvt. Ltd. He feels that a spacious place will solve the problem.. While building a house, people should plan for an open place to keep the pump. A branded company motor, which has ISO certification, is billed to produce less noise when compared to low quality motors. People who buy inferior quality motors to save some money end up suffering.
Solutions
Changing the ball bearings can reduce the noise to a great extent. New quality bearings for 1/2 or 1 HP motors widely used in houses cost Rs. 200.The problems in the shaft can be set right by welding it and adjusting its alignment and all this for another Rs. 200. Glad packing (grease rope) is done to avoid the sound from the shafts. Tightening the lock nut of the impeller can cost you only a few rupees.
Mr. Subramani feels that the water pump should not be switched on when there is single-phase power. It is dangerous and the motor windings will get burnt. Fix the motor in a place where it is not exposed to rain water and do not place motor under the staircase. The water pump should not slant when fixed. Leave a properly covered space of 4'x4' for your motor. Ensure that the motor is not overloaded (using lesser capacity motor or using it non-stop).
Buying water pumps of branded companies is advised. The branded motors are manufactured with "best fit" technology. "Best fit" refers to good inter-connected parts inside the motor. They are durable and less noisy. A branded water pump for 1/2 HP ranges from Rs. 2,500 to Rs. 4,000, only about Rs. 500 more that the low quality motors. A second-hand motor would have at least a few defects. If all these things do not reduce noise, you can opt for a sound-proof cover, depending on the size of the motor. It will cost around Rs. 900 to make a cover for a 1/2 HP or 1 HP water pump. This cover will have an open space (mouth) in the top and the sound can be diverted. This protects the pump from rainwater, says Mr. Subramani.
Opting for centrifugal pumps will be a good choice. It is more durable and its performance is good when compared to other kinds of motors, says Mr. Sharieff. For residential purposes, 1/2 HP motor is enough to pump water to the overhead tank up to the second floor. It can go up to 8 HP for high-rise buildings.
If you are looking for a totally soundless motor, you are in for disappointment. They are yet to be invented. Research has to be done in this regard, says Madhusudan L.G., of Kirloskar and Co. Silent pumps are the need of the hour, he says. One way of achieving it, according to Mr. Sampathraman, is to design a casing around the motors.
