The difference between run and start capacitors lies in how they store and release electrical energy to power key components in systems like air conditioners, generators, and refrigerators. Run capacitors provide a steady flow of energy to keep motors operating efficiently, while start capacitors deliver a quick burst of power to start them up. When a capacitor fails, it can cause your AC to stop cooling, your generator to lose voltage, or your refrigerator compressor to run inconsistently. Understanding which capacitor your appliance needs, and how to recognize the signs of a faulty one, can help you restore performance, reduce energy waste, and prevent costly breakdowns.
Run Capacitors
Run capacitors are more commonly used in air conditioning systems than start capacitors. The run capacitor in your AC is used to store energy, which is used to turn the fan motor, an essential component to your working AC. Without the run capacitor, the fan cannot turn.
Start Capacitors
Start capacitors are the second most commonly found capacitor within an AC system. Without a start capacitor, your AC will not start up at all, as it is the start capacitor that provides the initial energy needed for start-up. A lot of torque is necessary to start up an AC system, so a start capacitor will have greater capacitance than a run capacitor.
AC Capacitors
The term “AC capacitor” usually refers to your air conditioners run capacitor, simply because run capacitors are more commonly found in air conditioning systems. If you have a faulty run capacitor, your AC system will fail to cool your home properly or efficiently, resulting in wasted energy and money. If you have a faulty start capacitor, your AC may not run at all.
There are several key signs to look out for that might indicate that your AC capacitor is faulty.
- Your AC no longer blows cold air
- Your AC creates a low humming sound that wasn’t
there before - Your energy bills have been increasing
- Your AC sometimes does not turn on, or does not
turn on at all - Your AC turns off unexpectedly
Remember, if you are unsure if your AC capacitor needs replacing, you can use a multimeter to test your AC capacitor.
Generator Capacitor
Similarly to all the capacitors described above, a generator capacitor also stores electric charge. The generator capacitor provides the voltage, and regulates the voltage, within the generator. A low voltage reading may indicate that the generator capacitor is faulty.
You can test your generator capacitor using a multimeter.
Refrigerator Capacitor
A refrigerator capacitor most often refers to the more common run capacitor in a fridge.
The run capacitor in your fridge is likely to be located near the compressor, so signs that the run capacitor in your fridge might be faulty include:
- Hearing a clicking sound when the refrigerator
compressor runs - The refrigerator compressor seems to be running
too often (a few times an hour is normal, more when in frequent use) - The refrigerator compressor does not seem to be
running often enough
Replace Your Run Capacitor with Repair Clinic
Repair clinic has the guidance and parts you need to easily replace your run capacitor or start capacitor, in your AC, generator or refrigerator.