What Size Cable For Fan Heater? [Inc. 2 kW, 3 kW, & 4 kW]

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Winter is here! You may be eyeing a fan heater to keep your family warm. If you're unsure of the cable size needed for a fan heater, you're on the right page. We did the research to provide you with the best answer.

A 2 kW fan heater with a maximum current of 9 amps at 220 voltage works with a cable size of .75 mm. The recommended cable size for a 3 kW fan heater is 1.5 mm, while 2.5 mm is suggested for a 4 kW fan heater.

You should check the specifications of your fan heater, as this will help you determine the correct cable size. 

Selecting the right cable size for your new heater is important because if you choose the wrong cable, a short circuit might occur. Keep reading to learn about cable sizes and related information.

Recommended Cable Sizes For Fan Heaters

There are two types of fan heaters: residential and industrial. An industrial fan heater draws more power compared to a residential one. 

A residential fan heater usually has 2 kW and a maximum of 4 kW. It has limited capacity by voltage, amperes, and kilowatts. Amps and kW vary with the voltage.

Click here to see this fan heater on Amazon.

An online forum discussion shows that a 2 kW fan heater can draw a maximum current of 9 amps at 220 voltage and will need a .75 mm cable size.

A 3 kW draws between 13 to 16 amps maximum with a 230 voltage and a 1.5 mm cable requirement. A 4 kW drawing with a maximum current of 18 amps with 240 voltage will require a 2.5 mm cable size. 

The higher the consumption of kW, the bigger the cable size you'll need. If your appliance has a consumption of 2 kW, and you choose a .45mm cable size instead of the recommended size, it will burn your wire and your fan heater.

Factors to Consider When Choosing Cables

Woman plug in modern electric fan heater indoors, focus on device. - What Size Cable For Fan Heater [Inc. 2 kW, 3 kW, & 4 kW]

Choosing the correct cable size is essential to the safety of your home. Before installation, you must consider the current carrying capacity, regulated voltage, and short circuit rating. 

1. Current Carrying Capacity

Many electricians overlook this factor, but it's one of the most important things to consider because it determines the maximum current that runs through the insulated conductor. 

If the current rating exceeds its maximum allowable temperature, your appliance might overheat.

2. Regulated Voltage

All mechanical appliances have defined voltage ratings written on their manuals to maintain the power source within acceptable limits.

You should also do voltage regulation because a voltage drop due to the wrong length of cable can damage your appliance. 

3. Short-Circuit Rating

This also plays a vital role in cable selection, as it will determine whether the cable can withstand a short circuit. Determining a short circuit rating won't damage an appliance when a fault current occurs. 

Importance of Cable Sizing

Cable size includes the cross-sectional area of the conductor. It is measured with the voltage, amperes, and kW of a mechanical appliance. You can use a cable sizing calculator to get the exact cable size you need. 

Cable sizes are measured as mm (i.e. 1 mm, 2 mm, etc.). Here are some  reasons why proper cable sizing is important:

1. Your mechanical appliance can withstand a fault current.

2. You will avoid wasting money on a cable that's larger than you need.

3. You can avoid hazardous incidents associated with installing a cable that's too small for your appliance, which can cause overheating and might result in property damage. 

Difference Between Wires and Cables

Technically, wires and cables are the same. The only difference is the number of conductors.

A wire has only one conductor, while a cable is composed of a group of conductors. Each one has a specific application and installation process. Both conductors are made of copper. 

You measure wires in diameter. Inversely, a smaller wire results from a larger number, and a larger wire results from a smaller number.

In most cases, wires are bare, twisted, and coated with PVC. Both an inner and an outer sheath are present.

Stripped colored electrical wires. Copper multicore cables.

A cable is a group of wires braided or twisted together. It has better protection because it is usually insulated.

Electric screened cable with many wires isolated on grey.

A cable has three sets:


This wire carries the current. It plays the most important role in providing functionality for each part of an appliance.

Most of all, the wire should have a strong resistance to heat in order not to burn all the electronic parts of the machine and later cause an accident.

Neutral wire

The neutral wire helps complete the circuit. It is used as a bridge to connect all the components so that they function effectively. This wire is sensitive compared to the hotwire because it is smaller in width.

Grounding wire

A grounding wire is considered an additional path for the flow of an electric current. Its function is to absorb fluctuating current found in the circuit, so we do not get shocked when we touch an appliance.

What Happens If You Install The Wrong Wire?

The electrician repairs the electric heater.

According to members of a Q & A site, electrical installation errors can pose a serious threat to your family's safety as well as the safety of your neighborhood.

Because the wiring cannot sustain the electrical current, the incorrect type of wire can overheat and start a fire. Therefore, picking the proper wire size is very important. The thicker, the better.

Finding the wire's ampacity requires knowing the wire's size. There are many different sizes, and the ones below are some of the most commonly used:

  • 18-gauge wire - the thickness is 1.024 mm. This is suitable for low-voltage products such as electrical appliances and equipment, single LED lights, and other products with up to 47 voltages. This wire size can handle between 3 to 15 amps.
  • 16-gauge wire - the thickness is 1.291 mm. This is ideal for loads between 10 to 13 amps, such as extension cords and speakers. Recommended voltage is between 120 and 240, provided that amps must not be more than 13.
  • 14-gauge wire - the thickness is 1.628 mm. This can handle up to 15 amps. This is suitable for a product with up to 220 voltage.  
  • 12-gauge wire - the thickness is 2.052 mm. This wire size can handle up to 20 amps with a voltage not higher than 240. This is ideal for outdoor receptacles, bathrooms, kitchens, etc.
  • 10-gauge wire - the thickness is 2.588 mm. The wire size can handle up to 30 amps with a 240 voltage. Ideal products include air conditioners, electric heaters, and washing machines.
  • 6-gauge wire - the thickness is 4.115 mm. The wire size can accommodate between 32 to 60 amps. This is suitable for cooking appliances and ranges.
  • 4-gauge wire - the thickness is 5.189mm. The wire size can handle up to 85 amps. This is ideal for industrial products.

Click here to see this cable wire on Amazon.

How To Identify Electrical Cable Sizes

Electrical Cable Sizes

Cables come in a variety of sizes. Because each size has a different amount of current, you should learn how to identify the different cable sizes before deciding on one.

While using a cable that's too small can permanently damage wiring, using a cable that is too large is a waste of money.

Below are the simplified methods for identifying the electrical cable sizes. 

  1. Look at the insulation cable. Each cable has printed numbers or text denoting its size, and this represents the AWG of the wires. 
  2. Cut the wire. Use a wire cutter, and make sure you cut it perpendicularly to avoid cutting the inside wiring.
  3. Diameter measurement. The cross-section diameter must be measured in inches. Insulation in wires cannot be accounted for in the measurement.
  4. After the measurement, divide the result by 45. You may also use a cable sizing calculator for a more precise cable size.
  5. Determine the load it can handle.
  6. Look at the hues. White, black, green, and red should all be present. Ask the seller for more information if the colors are not specified.

In Closing

A fan heater can keep you warm during the winter and does not consume much energy. You can prevent the appliance from being damaged if you use the correct cable size. 

If this article has helped you, you might want to check out these related posts:

Ceramic Heater Vs. Fan Heater - Which To Choose?

Why Is My Cadet Heater Fan Not Working? [And How To Fix The Most Common Issue]

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