single phase 208 condensor motor

Techman

Hidy-Ho Neighbors,I agree with the 40+ years of experiance gentlemen. Cond fan motors have run caps not start caps .Start cap and/or run caps are in the start winding,and the start cap would have some sort of disconnecting device .Enjoy your day!

michael siena

single phase 208 condensor motor

greetings professor i had the pleasure of meeting you at my Oil 2 graduation at wilson tech. heres my question a condensor fan was wired at work. the fan had three wires and clearly the start cap was to be wired in series on the "purple lead" however it was not. when it was tested the motor would start after a push by hand. I suspected that the start cap was not in series and when the motor was spun the centrivical switch made and the motor ran. i am however smart enough to keep my mouth shut when there is a risk of flying tools! the solution was to go to the control panel and jump a hot lead from a contactor to the cap to solve the start up problem. now for my questions: was a start cap turned into a run cap? is the cap at greater risk of burnout? is the motor in any danger?

Thanks Michael R Siena

Eugene Silberstein 3

The Push

The push you gave the motor was serving the purpose of the start winding. The start winding gives the motor the imbalancein magnetic field that is needed to start the motor. Once the motor is close to operating speed, the centrifugal force pushes the contacts on the centrifugal switch open to remove the start winding from the circuit.

From your post, it seems that the start winding circuit was not complete, so you stepped in to give it some help.

As far as your question goes, it appears that the jumper wire was used to simply complete the circuit through the start winding. Your start capacitor should still operate as a start capacitor. In the event the start capacitor is remaining in the circuit all the time, you will be overheating your start winding as it too will be in the active circuit all the time.

It was great meeting you at Wilson Tech.

bob_50

Mike

In 40+ years I don't think I have ever seen a split phase or capacitor start induction run motor used to drive a condenser fan. Condenser fan motors are usually shaded pole, PSC(permenent split capacitor) or three phase. I suspect the motor you are testing is PSC. PSC motors do not have a starting switch. Psc motors have a run capacitor that is wired in series with the start winding and is in parallel with the run winding. If it is disconnected it will act as you describe.Is the capacitor round black plastic or a gray or silver metal can? Is the Mfd. rating of the capacitor approximately 10 Mfd or much larger? What is the voltage rating on the capacitor?

Empire_2

Thought this would help....

Amendment,...I thought there was some PSC info on fans before I threw this doc on the screen,...Sorry,.

MIke T.

kal_2

all three diags in the doc are for the compressor, not the fan!!

you can add my 40+ experiance to the above ones - also 9 to 1 odds its the fan motor thats bad not the run cap