When you are talking about electrical installation for homes, you will find electrical breakers in all homes. These electrical breakers disconnect the electricity supply in case of any issues like a short circuit. And since electrical breakers have to handle multiple electrical appliances and devices simultaneously, they are generally rated for high current loads. This can include 32-amp or 40-amp electrical breakers, depending on the electrical load.
However, any given electrical breaker will only be effective in terms of safety if the wires connected to it can also handle the same electrical load. This becomes even more important with heavy-duty 40 amp breakers which need heavy-duty electrical wires to prevent short circuits and electrical fires in your home. Hence, we have a detailed guide on picking the ideal wire size for 40 amp breakers. Going through this guide till the end, you can learn about the importance and the method of picking the ideal wire size for 40 amp breakers.
Ideal Wire Size for 40 Amp Breakers
Before going into any detailed explanations, many of you would like to know the ideal wire size for 40 amp breakers. So, if you are in the market for electrical wires that can handle a 40 amp breaker, then you should go with an 8 AWG wire for the same. This is because 8 AWG wires are meant to handle up to 50 amps of electric current. As a result, they can easily handle 40 amp breakers. But if you want to be safer, you can even go with a larger size like a 6 AWG wire.
Importance of Using Ideal Wire Size for 40 Amp Breakers
Now that you know the ideal wire size for 40 amp breakers, you might be wondering about the importance of the same. Let us tell you that it is highly important to use the ideal wire size for 40 amp breakers. While you can always use a larger-sized wire with your 40 amp breakers, using a wire larger than 8 AWG can be a bit cumbersome in terms of wire fitting and wire management. On the other hand, if you go with a smaller size than 8 AWG, then the wire will heat up due to electrical resistance. And this can lead to short circuits and electrical fires in your home.
How to Check Size of Wires for Amp Breakers?
If you buy electrical wires for the first time, you might be confused with wire sizes like 8 AWG or 6 AWG. To help you understand the same, you can simply consider this rating as the thickness of the wire. Compared with each other, a smaller 6 AWG rating will result in a thicker wire than an 8 AWG wire. As for picking these wire sizes, when working with a longer wire, it is essential to go with a thicker one. This is because if you go with a thick wire, it will have a large cross-sectional area, resulting in a lower electrical resistance. And this will then make the wire ideal for a heavy-duty electrical load.
Things to Consider for Choosing Ideal Wire Size for 40 Amp Breakers
Whenever picking any size of electrical wire for any application, it is crucial to keep a few things in mind. These are essential rules and points necessary to pick something functional. Similarly, you need to consider the following for choosing the ideal wire size for 40 amp breakers:
1. NEC 80% Rule
As per the NEC guidelines, any given electrical breaker should run at 80% or less capacity out of its total capacity for 3 hours or longer. In other words, if you use a 40 amp breaker, you can only use 80% or 32 amps of maximum continuous load with that electrical breaker. If you have a continuous electrical load higher than 80%, you will need to get a bigger electric breaker.
2. Wire Length
While we have already discussed that an 8 AWG wire is enough for a 40 amp breaker, things can change if you use a longer wire. If you are using a wire 100 feet or shorter, you should not run into any issues. However, if you are using a wire which is longer than 100 feet, then you will need to use a thicker wire like a 6 AWG wire.
3. Type of Wire
Another significant factor to remember while getting a wire for electrical breakers is the material used in the wire. While buying a wire for 40 amp breakers, you will find both copper and aluminum wire options. And when compared with each other, aluminum is not only cheaper but is also much lighter. That being said, if you wish to get longer wires, you should get copper ones since they are more conductive and won’t heat up easily.
Since electrical breakers are important for safety, choosing the correct wire is also equally important. This becomes even more important if you use heavy-duty electrical breakers like a 40 amp breaker. Therefore, we have already discussed all the details regarding choosing the ideal wire size for 40 amp breakers. We have even discussed the things you need to consider while getting a wire for 40 electric breakers.