One of the ceiling fans at home was spinning in the opposite direction (clock-wise) and so was sucking up the air rather than blowing it. I live in a hot climate so we always have the fans spinning in the counter-clockwise direction all year round. I need some guidance on safely correcting the direction of this fan. It's been 8 yrs since I last studied Electrical maintenance and honestly do not recall the wiring diagram.. 🙂
- Below is an image of the wiring of another fan that correctly spins in the counter-clockwise direction:
Observations:
- Input power supply: Yellow wires to the right
- Capacitor: White wires on the left
- Black: ?, Red: ?, Blue: ?
- Below is the wiring of the fan that spins in the clockwise direction:
a. Observations:
- Input power supply: Indicated on the right
- Capacitor: White wires on the left
- Black: ?, Red: ?, Yellow: ?
[UPDATE]
b. Observations:
- Swapped the red with Yellow.
- Fan remains stationary.
- Fan will start to move at constant speed in the direction I apply force in.
Product: Crompton Greaves Ceiling Fan – 220/240 V 50 Hz A.C.. SWEEP 1200mm (No lamp).
Wiring diagram: Could not locate the same. Kindly share any wiring diagrams that could help me better understand the same, Thanks..!
Kindly note: This is an Indian fan and the color codes are different from the US standard.
Color Codes: Phase: Red/Yellow/Blue, Neutral: Black, Ground: Green.
I tried checking with the manufacturer on this, but haven't received a response.. Not all single phase AC motors can reverse direction. [1][2]
Latest updates: We finally got a new fan and the old one was sold to scrap.. So while I am no longer able to test your solutions, I definitely look forward to technical explanation of the problem and possible solution(s). Thanks!
Best Answer
With another clockwise fan from the same maker, I was able to reverse the direction by interchanging the yellow and black wires as some answers here indicated. The explanation as I understood is that the rewiring changes the winding with which the capacitor is in series and hence the starting direction is inverted.
In 3-phase motors, each of the three stator windings carry a current out of phase with others and the phase difference generates the rotating magnetic field required to cause the motion. With single-phase ones, a phase difference is engineered by splitting the single phase current into two stator windings and putting a capacitor in series with one of the windings so that there's a 90° phase difference between the currents in the two windings. This page on electric motors explains the concept with illuminating animations.
The following figure shows my guess, based on the above information, at the internal wiring of the clockwise spinning fan whose image is posted in the question, for clockwise and anti-clockwise rotations.
A point to note here is that single-phase AC itself produces a changing magnetic field - though a pulsating one, not a rotating one. But this pulsating field can be resolved, as per the double field revolving theory (the link has an excellent video of the workings by the way), into two revolving fields rotating in opposite direction to each other. These two fields produce an equal but opposite torque. On a static rotor, they'll cancel each other out. But an initial rotation makes torque in one direction greater than the other and starts up the fan.
This is what, I believe, happened when the OP switched red and yellow wires on his fan. The result was that the capacitor was in series with both windings => there was no phase difference in the currents in the windings. When he added a slight initial rotation, the fan continued spinning in the nudged direction.