- Joined
- Apr 14, 2012
- Messages
- 78
Re: Capacitor questions
Each motor has one capacitor and both motor plates state 60 Hz. I have a PDF file of a short document that contains the wiring diagram and the connection diagram for the motors, switch, capacitors, and power. The thing is, I'm not sure how to get that on a post. I have looked all over the site and don't see a way to do it.
Yellow_cad Do you have one or 2 capicators on each motor or 1? Is the motor rated for 50Hz or 60Hz? The can type is not important though the can is a better Capicator construction shouldn't make a difference now. Simply put the capicator creates a phase change. I'm sure you have seen the typical sine wave similar to a backwards s on it side. That is the Voltage plotted to time. To shift the phase means that for any given interval in time the voltage is different, this diffrence is measured in degrees. So if I were to plot two same voltages that were 180 degress shifted it with look similar to an S and the backward S written in the same space and look like an 8 sideways. When a single phase motor is started it has no idea which way to spin so it usually don't. Spinning causes a counter emf (electro motive force) that's opposit to the input voltage and loweres the current. So if the motor doesn't rotate the winding will eventually burn up. To get the motor to start rotating a start winding is required because the coils get the change in voltage though oposite at exactly the same time the rotor does not know which was to turn. If you now plot the start voltage it would look like the sideways 8 with the side ways s starting in the middle of the o of the side ways 8. This shift will cause the rotor to move as it will be at max. when the others are at 0. In shaded pole motors a capicator is not required. In the capicator start motor a capicator is used to created the necessary phase change needed to get the motor to start, to change the direction the capitator is connected to the other side of the line. Though 115VAC motors use a Neutral the motor sees it as a power source and electically the two inputs are 180 degrees out of phase with each other the Capicators will cause a 90 degree shift in the start winding so that the motor will begin to rotate. In a single capicator motor the Capicator is switched off. Understand?
To understand your motor I need more info. Can you post a connection diagram? Where the motor is made is not important unless it's 50Hz as many other countries use 50Hz not 60Hz. You can't compare a 1/4 Hp motor to a 1Hp 2 speed motor. When you say work at low speed, will it try to start at high. Have you tried to start it with any belts removed? Have you tried getting the motor spinning at low and switch to high fast while it's still spinning?
Frank
Each motor has one capacitor and both motor plates state 60 Hz. I have a PDF file of a short document that contains the wiring diagram and the connection diagram for the motors, switch, capacitors, and power. The thing is, I'm not sure how to get that on a post. I have looked all over the site and don't see a way to do it.