Difference Between 15 Amp and 20 Amp Fuse

We all have seen or heard the news story of electric circuit failed in the certain shop or because of the short circuit there was a fire in the shop or home which led to a lot of personal stuff damage and a financial setback for the owner, so in below section, we would see detailed description how electrical systems has evolved over some time to solve these kinds of problem.

15 Amp vs 20 Amp Fuse

The main difference between 15 Amp and 20 amp fuse is that 15 amp allows lesser current load in the circuit which is suitable for home appliances whereas  20 amp fuse allows more current load in the circuit. The deciding factor on choosing which fuse to choose depends on the need and load in the circuit.

15 Amp and 20 Amp fuse

15 amp fuse use fuse wire that helps in the breaking the circuit when the current flow in the electric circuit is beyond a certain level. The current which flows in the circuit is equated as the combined wattage of all the electrical appliances divided by the voltage. Normally the voltage in our home circuit is in the range of 220-240 volts.

20 amp fuse also used for similar use as 15 amp fuse but choosing which one is the key factor because if choose the wrong fuse then eventually more current load will flow through the circuit that would lead to heat generation in the electrical wire and cause the short circuit and failure of the appliances.

Comparison Table Between 15 Amp and 20 Amp fuse

Parameters of comparison15 AMP20 AMP
Definition15 amperes of current in the circuit20 amperes of current in the circuit
Watts supportMaximum 1800 watts can flow in the circuitMaximum 2400 watts can flow in the circuit
Purpose This fuse satisfies the small power consumptionThis fuse satisfies the large scale power consumption
Compatability15 amp fuse could be used in place of 20 amp in emergency 20 amp can not be used in place of 15 amp fuse 
Found in15 amp could be used as a breaker for the home appliances like fans, 100W bulbs, etc20 Amp is used in heavy watts appliances like room heater, geysers, or industry level appliances.

What is a 15 Amp fuse?

The Discovery of the amp fuse goes back to the Thomas Edison era where he had devised the very first circuit breaker to prevent the short circuit and overload of the current in the circuit which used to lead to the failure of appliances but his innovation had set back where fuses have to be replaced constantly on every avalanche break however circuit breaker is one of the best innovation in an electric field to protect the home appliances by breaking the circuit.

15 Amp fuse came after so many improvisations from the initial version where the whole fused had to be replaced, now the use of a 15 amp fuse is very common in home wiring or the shops and even in the industries also where they have costly machines operating but it would break the circuit if watt is more than 1800 in the circuit.

A metal bar is present in the fuse which is made of a small cross-section. It is located in the middle of the pair of terminals. It is surrounded by non-combustible housing. The chain of fuses is properly arranged for the movement of charges. The fuse element is formed from a mixture of metals such as zinc, copper, silver, aluminum, etc., which show stable and predictable characteristics.

What is 20 Amp Fuse?

As we saw the use of the 15 Amp fuse in the above section and how the fuse has evolved from its initial version which was given by none other than Thomas Edison. Now we will see the use of the 20 amp fuse and its implications if use it in the wrong way.

20 amp fuse allows a higher magnitude of current to flow through the circuit and 2400 watts and if the watts exceed 2400 avalanche then the metal wire in the fuse will break the circuit. 20 amp fuse is recommended for higher watts products like heater, bigger air conditioning or geyser or industrial machines.

With the blown fuse because of load we can inspect and try to figure out what went wrong like if we find the vapourize metal around the glass of the fuse then the blow was violent and individuals should look for the cause also. We should not swape the 15 amp fuse with 20amp otherwise fuse won’t get blown and there will be a high load on the circuit which would lead to melting of the metal wire inside the wiring and cause a short circuit in-home or commercial building etc.

It is the property of the fuse that shows the uncertainty of the rated current and melts quickly. Apart from this, the fuse also does the work of increasing the effect of heat. If the fuse is large then the current is divided between the metal strips. In such a situation, if the metal strip is single then it melts during a short circuit. Steel or nichrome wires are supported by fuses to protect them from any kind of stress. In addition, it requires the use of a spring to increase the speed of its division.

Main Differences Between 15 Amp and 20 Amp fuse

The differences between 15 amp and 20 amp fuse could be distinguished based on the following points:

  1. 15 amp works well for small-scale appliances however 20 amp is more compatible for large scale appliances
  2. 15 amperes allows a maximum of 15 amp through the circuit whereas 20 amp allows 20 amperes of current in the circuit.
  3. 15 amp fuse will break the circuit if the watt exceeds 1800 whereas a 20 amp fuse will fail if it reaches the 2400 W avalanche.
  4. 15 amp is compatible with 20 amp outlet whereas 20 amp is not compatible with 15 amp outlet
  5. 15 amp fuse has thinner metal alloy, so it melts sooner in case of load whereas 20 amp fuse has thicker metal alloy to support more load.


As we saw the detailed explanation, how both 15 amp fuse and 20amp fuse has evolved since their first use over some time from replacing the whole fuse altogether to just replacing the fuse wire in the new era and then the key differences between them also, here we can conclude that both 15 amp and 20 amp fuse has the same purpose of breaking the circuit in case of the higher load than they can support to prevent any short circuit or failure of appliances but proper use of them is important like 20 amp fuse should be used for regular home appliances otherwise fuse won’t be able to detect the fault.


  1. http://www.foaxautomation.com/downloads/Principals%20of%20Electrical%20Grounding.pdf
  2. https://mospace.umsystem.edu/xmlui/handle/10355/9352
Help us improve. Rate this post! Total (0 votes,average: 0)