How to Buy the Right Fan Capacitor : The Ultimate Guide

You might have noticed a cylindrical/square shaped thing attached to your fan when you purchased it. The name of this crucial component is the fan capacitor. In most cases, this component gets damaged due to overheating, sudden voltage surge, and some other similar factors, making your fan non-functioning.

The main challenge comes when you need to replace it when such a situation occurs. Because finding a quality capacitor is quite challenging in the market. Most of them offer cheap prices as they are not up to the mark in terms of their service quality.

Today I’ll let you know how you should choose a quality fan capacitor that can serve you in the long run.

How to Know When Your Fan Capacitor Needs Replacement

When your fan capacitor is dead, it will show the following common symptoms, indicating your fan capacitor should be replaced-

1. Fan Won’t Start on Its Own

The primary role of the capacitor is to start the fan. If your fan is not spinning after switching it on, it's a primary indication your fan capacitor is dead. You can also get a burning smell as well when the capacitor is faulty.

2. Fan Runs Slowly or Unevenly

A weak capacitor can’t store enough charge, making the fan spin slowly even on the highest speed setting. You can also notice inconsistent spinning speed when the fan is switched on. If you experience such things, it's obvious that your fan capacitor is dead.

3. Overheating Motor

Set your fan to the highest speed setting and switch on your fan. If you hear a humming or buzzing sound from the motor area, it's another red flag. In most cases the motor gets overheated. But it can also happen when your fan coil is burnt. So, it's a good practice to check the capacitor with a multimeter to check its functionality.

4. Physical Damage to the Capacitor

If you directly inspect the capacitor, you might notice bulging, leaking oil, or burnt marks. Such things indicate that your fan capacitor needs immediate replacement.

How to Identify the Right Capacitor for Your Fan

Finding the right capacitor for your fan is the most crucial step. But thankfully the process is not that complex. By keeping just two factors in consideration, you can easily find the right fan capacitor.

Step- 1: Check the Label on Your Old Capacitor

Your old capacitor is the primary thing that can help you find the perfect replacement. You’ll have to uninstall it from your fan (don’t forget to disconnect the power, of course!) and check out the information printed on it. Here are the critical numbers you need to note down-

• Capacitance (µF or MFD): This is the most important number you should note down first and should match exactly how it is. This number indicates the power of capacitors. And the power of capacitors are measured in microfarads and written in 5µF or MFD. If you install a capacitor with the wrong µF, it can make your fan motor run too fast, too low, or even overheat, which can eventually damage your fan permanently.
• Voltage Rating (V or VAC): This number indicates how much power your capacitor can handle (not the voltage it can deliver). Here, the rule is simple - just match the number with your old capacitor, or just go higher when you buy the new capacitor (but never go for the lower option). For example, if your old capacitor is rated at 370V, you can just buy the new one with 370V rated capacity, or you can choose the 440V option also.
• Tolerance (%): You might see a percentage like ±5% or ±10%. These numbers indicate the acceptable range of capacitance. This number is less critical for most fans compared to the other two factors we mentioned. But it’s always a good practice to match with the number when you buy a new one.

Step-2: Understanding 2-Wire vs. 3-Wire Capacitors

Not only the rated voltage or capacitance differ between the capacitors. They differ in wiring also-

• 2-Wire Capacitors: This is the most simple and common capacitor that is widely used in the fans with simple mechanisms (like basic stand fans, exhaust fans, etc). It comes with a single capacitance value and is used only to start the motor.
• 3-Wire (or Dual Run) Capacitors: These capacitors are widely used in ceiling fans that require multiple speed settings. They are mainly two capacitors combined into a single unit. So you’ll see two capacitance values that are mostly written as 4.5µF + 6µF, or you might see two different labels printed on the casing for both. One value indicates it can help run the fan motor, and another one is dedicated to regulate different speeds.

Step-by-Step Guide to Buying the Right Fan Capacitor

Now you know what specifications to check out to find the right one for your fan. Now, let’s discuss the right process to buy a quality fan capacitor from the endless options available in the market.

Step 1: Get Your Information Ready

Before you even step out of your home or open your favourite shopping app, you need to be prepared first. Make sure you’ve made the following things ready-

• Safety First: Make sure the old capacitor is unplugged from the direct electric supply. Also make sure it’s completely discharged to prevent accidental shock.
• Take a Picture: Take a clear photo of the label of the capacitor with your smartphone. Especially, make sure the numbers (µF and V) are clearly visible in your picture.
• Write it Down: If you want a backup, you can write down the number on a piece of paper . Again, be extra careful when writing down the correct numbers.
• The Golden Rule: If your old capacitor is damaged but the label is intact, take your old capacitor with you so that you can show it directly to the shop owner. This is the foolproof way to get the perfect match.

Step 2: Know Where to Buy

In Bangladesh, you have several good options for buying a fan capacitor-

• Your Local Electronics Repair Shop: In most cases, you’ll find your fan capacitor in your neighbourhood electronic repairing shop. It's the quickest and convenient solution.
• Authorized Service Centers: If the manufacturing company of your fan has authorized outlets for servicing, you can contact them also to find the exact replacement.
• Online Stores: You can check out prominent stores like LAXFO Electronics who are uncompromised in providing quality fan capacitors.

Step 3: Consider the Quality and Price

• Quality: There are various brands in the market, mostly made in China. Some of them come with good quality. Try to get the good one even if it requires extra money.
• Price: A standard fan capacitor costs between BDT 100 to BDT 400 depending on the brand and quality. Sometimes the cost might be higher if the quality is top-notch.

Ending Note

Finding the right fan capacitor might seem technical, and it’s not incorrect. But following the right way can help your process easier for any non technical person. We believe the process stated in the blog is sufficient to guide a non-techy guy. If you still struggle, you can ask a good technician to help you.

FAQ

What type of capacitor is used in a fan?

Standard fans with simple mechanisms (exhaust fans, basic stand fans) need 2-wired capacitors to run. Some ceiling fans need 3 wire capacitors as they require different speed settings.

Is a 3.15 mfd capacitor good for ceiling fans?

3.15 mfd capacitor is a good capacitor for ceiling fans as its rated voltage is 440V. As it can handle high voltage surge, you can use it for your fan capacitor.

What does a capacitor do to a fan?

A capacitor typically works to start your fan. This equipment can store energy and make sure your fan spins smoothly.

What if I connect a 3.5 µF capacitor instead of 2.5 in a ceiling fan?

Using a 3.5 µF capacitor instead of 2.5 for your fan is not a recommended practice. You might get increased speed due to the higher number. But it will make your fan overheat, reducing its lifespan.