How does a capacitor work in a 208 volt single phase blower motor. My thought is that when voltage is applied the capacitor releases a charge to the start windings. Then after it releases its charge it doesn't allow anymore current to flow until it has voltage applied to it again allowing only the use of the run winding for current flow. Also does a capacitor only allow current to flow in one direction?
Capacitor
- Thread starter JdoubleU
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ptonsparky
Tom
- Occupation
- EC - retired
Capacitors can be used on the start only, start & run, or run. Depends on the type of motor being used for the type of load you have. The voltage applied to the motor doesn't have a lot to do with how the capacitor functions.
Capacitors block current flow in a DC circuit, after initial charge, and allow current flow in an AC.
Someone else will have to chime in with all the details. It has been to long since school.
Capacitors block current flow in a DC circuit, after initial charge, and allow current flow in an AC.
Someone else will have to chime in with all the details. It has been to long since school.
AdrianWint
Senior Member
- Location
- Midlands, UK
Alas, your understanding is not correct.
When AC flows through a capacitor, the voltage & current are not in phase - the current leads the voltage by 90 degrees. Since the capacitor is in series with the start winding, the current in the start winding leads the current in the run winding by 90 degress - the field appears to 'rotate' thus causing the rotor to turn.
Without this phase shift the field wouldnt rotate, just build & collapse in sympathy with the voltage - their would be no torque on the rotor & it wouldnt spin.
Adrian
When AC flows through a capacitor, the voltage & current are not in phase - the current leads the voltage by 90 degrees. Since the capacitor is in series with the start winding, the current in the start winding leads the current in the run winding by 90 degress - the field appears to 'rotate' thus causing the rotor to turn.
Without this phase shift the field wouldnt rotate, just build & collapse in sympathy with the voltage - their would be no torque on the rotor & it wouldnt spin.
Adrian
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