Read the capacitor that you remove
A capacitor start motor is a split phase motor that uses a capacitor in series with the start winding to cause a greater phase shift, resulting in greater starting torque. It uses a centrifugal switch to switch out the start winding and capacitor once the motor is up to speed. I assume this switch is what you're referring to as a "relay".
It sounds like the starting capacitor is about to give up.
To induce a phase shift between the rotor and stator (stationary winding). AC motors are not good at starting up, they need 'help' to get started/they need two magnetic fields to push against each other to generate torque. This capacitor is called a 'starting' capacitor and provides an extra 'boost' to get the motor turning by increasing the phase angle between the rotor and stator winding. Once the motor is at it's proper operating speed, the capacitor must be disconnected or it will burn up. There are also motor designs that use a run capacitor. This capacitor usually has a smaller capacitance than a start capacitor (so it provides a smaller phase shift), but is designed for continuous operation. These motors don't provide as much starting torque as a similar motor with a start capacitor. Other motors will have both a start and run capacitor. The start capacitor provides significant phase shift between the rotor and stator, and thus significant torque. Once the motor is at speed, the start capacitor is switched out of the circuit, and the run capacitor is left in the circuit to provide a smaller phase shift.
No. A starter capacitor is just that....for start up purposes only. It does not control speed....this is done by selecting different phases of the running motor wired individually. Motors that rev up and down are called stepper motors and can be controlled by dedicated operating control boards that constantly monitor amps and load resistance.
Read the capacitor that you remove
Easier to start up. Running remains the same unless it is equipped with a run capacitor too. A run capacitor uses a little less current during run and probably runs a little cooler too.
A capacitor start motor is a split phase motor that uses a capacitor in series with the start winding to cause a greater phase shift, resulting in greater starting torque. It uses a centrifugal switch to switch out the start winding and capacitor once the motor is up to speed. I assume this switch is what you're referring to as a "relay".
the start relay helps the compressor start up then takes itself out of play when the compressor gets going. The older units will have a capacitor and a relay mounted in the control panel and the new ones are all in one...you just parallel the run capacitor.
It sounds like the starting capacitor is about to give up.
The capacitor boosts the motor.
To induce a phase shift between the rotor and stator (stationary winding). AC motors are not good at starting up, they need 'help' to get started/they need two magnetic fields to push against each other to generate torque. This capacitor is called a 'starting' capacitor and provides an extra 'boost' to get the motor turning by increasing the phase angle between the rotor and stator winding. Once the motor is at it's proper operating speed, the capacitor must be disconnected or it will burn up. There are also motor designs that use a run capacitor. This capacitor usually has a smaller capacitance than a start capacitor (so it provides a smaller phase shift), but is designed for continuous operation. These motors don't provide as much starting torque as a similar motor with a start capacitor. Other motors will have both a start and run capacitor. The start capacitor provides significant phase shift between the rotor and stator, and thus significant torque. Once the motor is at speed, the start capacitor is switched out of the circuit, and the run capacitor is left in the circuit to provide a smaller phase shift.
Most ceiling fans use a type of motor known as a "permanent split capacitor motor". These motors have two coils, a "start" and a "run" winding. A capacitor is connected in series with the start winding to insert a phase shift, but once the motor is up to speed it becomes an auxiliary winding. In order to reverse the motor, the capacitor is applied to the "run" winding which then becomes the "start" winding. In some cases the windings may have taps to provide different speeds, in others the value of the start/run capacitor is lowered to provide lower speeds. Yet other designs will have additional capacitors wired in series with the motor as a whole to regulate speeds.
The start winding needs a capacitor in series with it in order to produce a phase shifted magnetic field that will develop the torque necessary to bring the rotor up to operating speed. Once operating speed it obtained, a centrifugal switch opens and disconnects the start winding - the rotor's inertia can then keep it going as needed.
No. A starter capacitor is just that....for start up purposes only. It does not control speed....this is done by selecting different phases of the running motor wired individually. Motors that rev up and down are called stepper motors and can be controlled by dedicated operating control boards that constantly monitor amps and load resistance.
To plot a current vs. time graph for a capacitor being charged, you would typically see the current start high and decrease as the capacitor charges up. The rate of decrease in current depends on the capacitance and the resistance in the circuit. To analyze this, you can use the formula for charging a capacitor: I = C(dV/dt), where I is the current, C is the capacitance, and dV/dt is the rate of change of voltage across the capacitor.
A capacitor resists a change of voltage, proportional to current, and inversely proportional to capacitance. dv/dt = i/c Capacitors can do various things. They can filter out high frequency transients, or power supply ripples, they can block DC while passing AC, they can participate with other components such as resistors and inductors to form filters - the list is endless.