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Can An 8 Gauge Wire Handle A 50 Amps? (Explained)

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Last updated on August 14th, 2022 at 01:27 pm

If you’re observant, you will notice that wires used in domestic wiring come in different sizes. While they all serve in various capacities, not all are compatible with every current flow.

So, if you have an eight gauge wire but aren’t sure whether it will work with the 50 amps current in your home, you may wonder if they are compatible.

An eight gauge wire can handle a 50 amps current. However, it will get quite hot, even as high as 75°C. According to the thumb rule, a higher current requires fewer gauges because of its thickness and ability to absorb excess heat that causes wires to melt. However, an eight-wire gauge can handle 50 amps current only if the wire is thick, otherwise don’t use it for an extended period.

How Many Amps Can 8 Gauge Wire Handle?

Ideally, an 8 Gauge wire can handle 40 amps current. Since it’s a lesser current, it needs more gauges.

An eight gauge wire has a diameter of 3.26mm. This is not too wide compared to the 6, 4, and 2 gauge wires.

Imagine having a pipe of such diameter, and a specific volume of liquid is passed through it; you’ll notice that it moves in and out of the tube with ease.

As such, there is free movement of the liquid. But if more volume of water is made to pass through that same pipe, its pressure increases, and the line will burst.

This is the same with wire gauges and the flow of current. An eight gauge wire is made to handle a current of 40 amps.

But if a current of 60 amps, for instance, runs through it, the flow would be too much for it to handle.

This is because it wasn’t designed to take too much current as it is not thick enough for such an amount of current.

You may think to yourself, “if an eight gauge wire can handle just 40 amps, and a six gauge wire can handle just 50 amps then, what can handle a current of 45 amps?”

It is essential to know that the calculation doesn’t work as a mathematical word problem. This means that if an eight gauge wire can handle 40 amps, it can also take 45 amps of current.

So it’s not just applying simple logic but also applying knowledge about the current ranges it can handle. This rule also applies to other wire gauges.

When you decide to overlook this by using any wire gauge you lay your hands on, it could cause a short circuit.

This happens when the wire comes in contact with other cables due to a melted protective insulator.

For your insulator to be melted, you must have used a thinner wire for a certain amount of current. Therefore, it is advisable to stick with the rules.

Hence, an eight-wire gauge should handle about 40-45 amps of current.

Factors That Affect Choice Of Electrical Wires?

When choosing a wire gauge, you should consider the distance, gauge, wire type, wattage load, insulation, and ampacity.

Distance matters in choosing a wire because the longer the distance, the lower the gauge number.

Voltage is lost through resistance when the wire is very long. It is normal to have long wires, especially when the distance is long.

So in this situation, what you should do is to increase the wire gauge, thereby making the voltage drop.

This will increase the amperage capacity. Again, before choosing a wire, you should consider the gauge to know if it fits the amount of current.

Here’s how to know the amount of current flowing in a circuit quickly.

First, you need to add all the wattages of the electrical devices on the circuit, then divide the total by the system’s voltage, which is either 120 volts or 240 volts.

The result is the amount of current flowing in the circuit. With that, you determine the number of gauge wires to use.

Also, wattage load and ampacity should be considered. If you do not understand what this is all about, you should get an electrician to check it all out for you.

But I’ll be explaining this here to give you an idea about it. The wattage load is simply the amount of power it can accommodate, while the ampacity is the amount of current flowing through the wire.

Wires have letters written on them to know the type of insulation. It could be heat resistant with the letter H or thermoplastic insulation with the letter T or W, which means it is water-resistant.

Knowing the type of wire is crucial as it depends on what you’re using it for. Different uses require different wires, and insulations should be appropriately followed.

For example, using a wire that is not water-resistant in a wet place is wrong.

Can I Use 10 Gauge Wire On A 50 Amp Breaker?

Using a ten gauge wire on a 50 amp breaker is not advisable.

As aforementioned, the amount of current determines the gauge wire used.

In this case, a circuit breaker that helps protect electrical circuits when there is excess current is no exception.

If your circuit breaker has a 50 amp current flow, then a six gauge wire is ideal and not a ten gauge wire.

A 10 gauge wire is too thin for a 50 amp current to pass through. This doesn’t mean you can’t use a ten gauge wire on a 50 amp breaker.

The issue is that it will heat up frequently. This could cause short circuits and fire outbreaks.

Furthermore, the current that flows in a 50 amp circuit is high, so there is a need to choose a suitable conductor wire for wiring.

In addition, the type of wire used can determine the gauge wire. An aluminum four gauge wire is best for a 50 amp circuit.

This solely depends on the type of conductor used. However, this does not justify using a ten gauge wire on a 50 amp breaker as it is totally out of place.

Rather than forcing a ten gauge wire on a 50 amp breaker, it would be perfect for a 30 amp breaker.

This breaker type is not loaded, and the current flow is not as high as the 50 amp breaker. A 6 gauge wire is more than okay for this 50 amp breaker.

Finally, to avoid hazards of any kind, please stick to using the recommended wires.


Going through the thumb rule would help choose gauge wires for electrical circuits.

Although not too suitable, an eight gauge wire can handle a 50 amp current. Instead, it is best for a 40 amp current.

One doesn’t choose wires just because you know the diameter and current being passed.

You should also look out for other factors that might affect the wire if not looked into. These factors have been briefly discussed.

Finally, a ten gauge wire is unsuitable for a 50 amp breaker.


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