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Why ceiling fan's rated speed gets reduced as the time passes?

Date: 02 Apr 2016   Posted By: Paresh Gujarati     Group: Science and Technology    Category: Technology   

When we use a new ceiling fan, the rotational speed set at 1,2,3,4 & 5 are as per the rated speed. But as the time passes, we experience that at 5 the fan is running at 3 or 2 level. Why does this happen over the time? What is the solution for this?
Experts: do respond.

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Author: Kailash Kumar    03 Apr 2016      Member Level: Platinum     Points : 3  (Rs 3)    Voting Score: 0

The following may be possible reasons -
1. Bearings may be getting worn out.
2. The capacitor controls the level of power that goes to the fan at each speed. In case the capacitor has either failed or failing out, then it is likely to affect the speed.
3. In case of cheaper kinds of fans, the windings in the motor may be beginning to fail.
Equal power is consumed at all speeds. The electric regulators have resistors to decrease the voltage for the ceiling fan. In electronic regulators capacitors are provided instead of resistors to decrease the voltage.
Perhaps by changing the regulator, the problem may get resolved in case the same is due to regulator only. Otherwise only physical inspection of the system may throw some light on the subject matter.

Author: Mahesh    04 Apr 2016      Member Level: Gold     Points : 3  (Rs 3)    Voting Score: 0

The components of the fan motor age out as time goes on. For example, the motor has some specific age for functionality due to the magnetic field. After some time the coil ages out. And this reduces the fan speed too. So you have to reduce the fan over a period of years.

Many times what happens is that fan also goes through some of the shock surge and ending up making coils damaged. That's why you should never keep fan button on when the lights go out. As that helps in wear and tear of the fan.

You can expect any fan to have a life span of about 5 years. After that it is wise to change the fan motor and the blades too.

Author: Sheo Shankar Jha    04 Apr 2016      Member Level: Gold     Points : 5  (Rs 5)    Voting Score: 0

The reasons for low speed of the fan are as follow-
1) Motor - winding plays an important part in the regulation of speed. With the constant use of fans, the windings normally made of Copper - turnings get damaged in absence of proper insulation or the manufacturer might have used low quality of material. The solution lies in taking up fresh windings by an efficient Electrician.
2) Replacement of Capicitors would be required in case of low speed. The Capicitors fail due to worn out of wires lying inside it.
3) Bearing provided inside the fan may get damaged with constant use. The worn out Bearings are to be replaced.
4) Ceilings - fan are provided with fly - wheels made of rubber and the the hooks of the fan rests on these rubber fly - wheel and over the time, these get snapped or damaged resulting in movement of the upper part as well. This affects the speed of the fan.
5) Fluctuation of supply - voltage also affects the speed of fans. In order to maintain constant speed of the fan, a Stabilisor is required to be installed in the house - hold in order to run the fans at uniform speed.

Author: Hardik Joshi    05 Apr 2016      Member Level: Silver     Points : 5  (Rs 5)    Voting Score: 0

Many a times machinery will not plays its function properly. In the case of Ceiling fan, if its speed reduces as the time passes, following are the reasons for this malfunctioning:
1. Shape of the blade
Fans blades are so designed that it's have minimum air resistance. It may happen that while cleaning fan, blades may be bend little bit.
2. Capacitor
In our Electricity line, current lag behind the voltage but in fan voltage should be lag behind the current. Capacitor is used to make this change. If this change will not possible, fan will not perform its function well.
3. Bearing
Bearing may be worn out or it gets chocked due to dust.
4. Motor Winding
Motor winding made of copper material get damaged with time passes if insulation is nor proper.
5. Voltage Fluctuation
All the electronic items will not work properly if voltage supply is not uniform.

Author: Adarsh kumar    05 Apr 2016      Member Level: Silver     Points : 6  (Rs 6)    Voting Score: 0

There are many reasons for this reduction in number of oscillations of the wings of fan.
Some of the reasons are given below-

1. Ball bearings getting worn out.

2. The fluid in the capacitor getting defragmented.

3. Copper winding getting damaged over time.

4. The number of oscillations also changes season wise depending on temperature conditions.

5. Attachment of more appliances in the circuit.

6. The internal magnets loose their permeability with time.

7. Low voltage supply especially during summer season because of too much load on the transformer.

Author: Partha Kansabanik    05 Apr 2016      Member Level: Diamond     Points : 2  (Rs 2)    Voting Score: 0

The main reason for reduction of speed of old fans is wears & tears of ball-bearings due to friction. Voltage fluctuations and the problem in capacitors of old fans are another two reasons for reduction of speed of old fans. In case of wear & tear of ball bearings, the old fan is required to be replaced by new fan.

Author: Venkiteswaran.    05 Apr 2016      Member Level: Diamond     Points : 3  (Rs 3)    Voting Score: 0

Some improvement can be obtained by regular cleaning of the fan blades. The fan blades of present day are very light and the dust gathered on them and accumulated at the edges make them heavy. This affects the rotating speed. If they are cleaned regularly and kept clean of dust and dirt, then the sped can be maintained to some extent.
This is form my practical experience.

While cleaning please take care that you do not bend or twist the blades. One should clean gently applying less pressure using first a wet cloth and then a dry cloth. A vacuum cleaner also may be used.

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