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How Long Do Microwave Capacitors Hold Charge?

There is no doubt that microwave ovens are a great convenience in the kitchen. However, they also represent a potential safety hazard, and this is often caused by high voltage. This is where a capacitor comes in because it regulates that voltage.

That said, there are many of these appliances in the market, so it can be hard to tell if yours is getting sufficient voltage. But how long do microwave capacitors hold a charge? Each capacitor’s discharge time is different with most microwave capacitors taking several days for their charge to naturally discharge on its own.

Manually discharging a microwave capacitor takes 10 to 20 seconds to empty the charge if done right.

What is a Microwave Capacitor?

Before we get into how long microwave capacitors can hold a charge, it is important to understand how they work. A microwave capacitor is an electronic component that can be used to store electric charge.

A typical capacitor consists of two conductive plates separated by an insulator. When you apply a voltage across the plates, electrons will move from one plate to the other, creating a charge imbalance. This imbalance produces what is known as an electric field between the plates.

The electric field then causes an attraction between the plates. As more voltage is applied to the plates, more electrons move from one plate to another, and this attraction increases.

Now, the amount of energy stored in a capacitor depends on how much voltage was applied during charging and how long it took to charge up.

In a microwave oven, the primary function of the capacitor is to regulate voltage. The thing is that microwaves are inconsistent appliances mainly because they use a lot of power. This can then cause the appliance to break and ultimately stop working.

The capacitor allows the required current to pass through at a time.

How Long Does It Take For Capacitors To Discharge?

As previously mentioned, microwave capacitors work by regulating voltage. This is because the microwaves in your appliance can cause it to malfunction or fail to work altogether. A capacitor can be termed as an electronic device that not only stores electricity but also releases it as required.

That said, you want to keep in mind that the size of your capacitor will determine how long it will take to discharge. For instance, one with ¾ inch in height and 1-2 inches in diameter can store 2-3 energy joules on average and can be manually discharged within 10-20 seconds.

How to Tell if Your Microwave Capacitor Is Discharged

You are probably wondering how to tell if your microwave capacitor is discharged.

You see, it is common for power surges to occur. This is not good as it can lead to fire or even the destruction of appliances. Capacitors work by storing extra energy, which comes in handy during power surges or fast power discharge.

Your microwave, just like any other appliance, is prone to occasional disruptions. Therefore, whenever you try to repair yours, it is important to discharge its capacitor to prevent injury during the repair.

In that regard, there are several measures you can put in place to guarantee the discharging of your capacitor. The first step should involve detaching your capacitor from its power supply. After that, you want to set a maximum DC voltage, as it will help you get accurate capacitor readings.

Next, link your multimeter to your capacitor. You do this by joining the multimeter’s red lead to the capacitor’s posts. You then want to join the black lead to alternating posts. In so doing, the capacitor’s voltage will be displayed.

With a Screw Driver

Chances are that you don’t have a multimeter at hand, but that should not be a reason to worry. You can use a regular screwdriver instead. That said, remember to avoid touching the capacitor terminals as they pose a hazard.

Use a screwdriver with a rubber handle to be safer. You then want to hold the base of the capacitor but do not squeeze it too much. With your screwdriver, touch its posts. Once you do that, you will see sparks flying and crackling sounds. Continue doing this until there are sparks or sounds. This will be an indication that the capacitor is fully discharged.

By Making a Capacitor Discharge Tool

Before we get into this, it’s best to note that it is a time-consuming technique. You will be required to cut 15-centimeter-long pieces from a 12-gauge wire. Slash about 1.5 cm of insulation from the end of both wires.

Next, you want to cover the wires with electrical tape or shrink wrap once you have soldered one end. After that, join alligator clips to the other end of the wire. Gently link the clips to your capacitor terminals, and it will rapidly be discharged.

How do you Know It’s Time to Replace Your Capacitor?

Regardless of how well your microwave’s capacitors hold a charge, they will wear out and require replacement over time. These are the signs you need to look out for as they signal that it is time for a replacement.

  • Dim light – Earlier microwave models used to have powerful lights that could brighten up an entire room. Now, they can only light up a portion of a room. Why? Because these appliances require more voltage to offer bright lighting. Therefore if you notice that your microwave light is dimmer than before, it signifies that you need a capacitor replacement.
  • Blowing fuses – If you realize that multiple fuses blow when your microwave is in use, chances are that you need a new capacitor. This is because newer microwave models have high voltages and consume more power.
  • Popping or hissing sounds – Are you hearing hissing or popping sounds from your appliance even when it is off? This could be a sign that the capacitor is malfunctioning and needs a prompt replacement.

Why Does a Capacitor Need to be Discharged?

A capacitor will always hold its charge even when disconnected until it is discharged. What most people don’t know is that the microwave uses extremely high voltage to heat food, and because of that, its capacitor can hold harmful charges.

While fixing your appliance, you may encounter some components inside it that could complete a circuit. This may, in turn, have electricity passing through your body. Discharging the capacitor will prevent that from happening.

How Long Should You Wait When Changing a Microwave Capacitor?

The answer here is relative. It depends on several factors, including how often you use your microwave, its age, and the capacitor type.

The capacitor plays a crucial role in your appliance, so it is advisable to change yours as soon as it begins to malfunction or show signs of damage.