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Reverse single phase cap. start AC fan motor

Thread starter #1
New here-hope someone can help me reverse direction on a 1/3 hp. single phase, 2 speed, capacitor start fan motor. Runs CW looking from back of motor. Hope pictures are enough to determine what needs to be done. Capacitor brown and white wires coming in from left .Brown wire soldered to single strand of winding. White capacitor wire soldered to single strand and another insulated wire that disappears into the motor. Black (hi speed) and red (low speed) incoming wires from right both soldered to 2 strands of winding. Not afraid to get my hands dirty,
Just don't understand enough to do it. Thanks in advance for any and all help. P_20190414_175020_LL.jpg P_20190414_175038_LL.jpg P_20190414_175134_LL.jpg
 
#2
Fan motors are usually connected internally without the option of reverse, the easiest way is to detect the coil the cap is connected to and identify both ends of the this start winding and reverse both connections. one will go to the neutral and the other the cap, I suspect.
Max.
 
#4
Are you saying to reverse the leads from the cap?
Max is not saying that, as reversing the capacitor won't make any difference.

What I would start with is to disconnect the capacitor and check if the motor will run in either direction when you start it by hand. If not, then that motor probably won't work.

The motor won't mind being stalled for a few seconds after you turn it on, before you have spun it to get it going. However it will be damaged if you power it with no motor.

The motor being 2 speed makes it more difficult than usual to reverse. The circuit is more complicated than the normal single speed. In single speed motors, one end of the capacitor is usually connected to one of the input wires, and they can be reversed by connecting that end of the capacitor to the other input wire. I can't see a simple equivalent here.
 

dr pepper

Well-Known Member
Most Helpful Member
#5
Check to make sure its physically compatible first, and make sure the rotor lines up with the core.
One way I've had success with in past is just reversing the corepack, unbolt it turn it around & rebuild the motor, it goes the other way.
Saves digging into the windings for re-connecting.
Doesnt work for all motors though depending on construction.
 
#6
One way I've had success with in past is just reversing the corepack, unbolt it turn it around & rebuild the motor, it goes the other way.
Doesnt work for all motors though depending on construction.
Good idea.
Incidentally this is the only way a shaded pole motor can be reversed.
Not very practical if you need often reversal though.
Max.
 
#7
If the motor does not have 2 extra reversing wires then it can not be made to run the other direction. All you do is swap the 2 wires then it runs the other direction. You can not add the 2 extra wires unless your rip out all the copper wire then rewind the motor with the 2 extra wires it needs.
 
#8
They usually have a separate start winding with one end connected to the N and the other to the cap, if these are located they could be swapped to reverse.
They don't offer the option as its function is designated for a fan.
Max.
 

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