10mm Cable Amps Rating Explained (With Examples)

10mm cable amps ratings

You cannot use the same cable sizes for every appliance in your home. Manufacturers make conductors in different sizes because they have to accommodate the varied electrical needs of the equipment in your house. You are probably familiar with 1mm, 1.5mm, and 2.5mm because people use these sizes in lighting circuits and sockets. But what about 10mm wiring? What purpose does it serve? Better yet, what kind of load can it carry?

How Many Amps Can 10MM Cable Carry?

10mm cables can tolerate anywhere between 32 and 64 amps depending on various factors including location, the length of the cable and ambient temperature.

Situation (10mm)Amps
Wire enclosed in an insulated wall44A
Enclosed in conduit52A
Thermal insulation in contact with the ceiling < 100mm45A
Thermal insulation in contact with the ceiling > 100mm36A
Thermal Insulation cable touching the wall47A
Thermal Insulation cable not touching the wall32A

The amperage of an electrical cable refers to its current carrying capacity. This is the definition most electricians repeat. However, that definition doesn’t mention the heat, which is vital to the amperage.

10mm cables can carry far more than 70 amps of current. But electricians are not necessarily concerned about the maximum amount of electricity a conductor can take.

Rather, they want to identify the volume of current a wire will safely transmit. This is because every conductor generates heat when it transports electricity from one point to another.

The electricity produces heat when it encounters the resistance in a conductor.

Yes, 10mm cables can carry more than 70 amps of current. But eventually, if you force enough electricity through a conductor, the copper or aluminum will melt.

If the heat is not strong enough to melt the conductor, it can still start a fire by igniting papers, curtains, sheets, and any other combustible components in the vicinity.

The purpose of determining a wire’s amperage is to find the amount of electricity it can handle without raising the heat to dangerous levels.

However, heat is not the only factor that matters. You must also consider the following:

1). Ambient Temperature

If the goal is to limit the amount of heat a current generates when it passes through a conductor, you must pay attention to the ambient temperature. Conductors in settings with higher ambient temperatures are more likely to overheat.

Therefore, you have to lower the current passing through the wire if the ambient temperature is too high.

2). Temperature Rating

The ambient temperature and temperature rating go hand in hand. Many manufacturers design cables with higher temperature ratings. These conductors work in settings with higher ambient temperatures, which is why their amp ratings are equally high.

They can tolerate problematic ambient temperatures without overheating. Wires with lower temperature ratings are the opposite. They have lower amp ratings. If you look at the tables your contractors and engineers use, you will notice that they reveal the amp ratings of different wire sizes depending on their temperature ratings.

The temperature rating a contractor selects will depend largely on the ambient temperature of the setting.

3).  Location

Where do you intend to install the 10mm cables?

  • Will you run them through conduits and ducts?
  • Do you want to bury the conductors underground?
  • Or will they remain free in the air?

The setting affects the ventilation.

You should install wires with higher temperature ratings in places with poor ventilation. Some people use cooling systems to counteract the overheating that may occur.

4). Size

This goes without saying. The size of the conductor affects the current carrying capacity. Think of a water pipe. The wider the pipe, the more water it can carry. Conductors are the same. The largest loads require the thickest conductors.

This is why electricians prioritize the thickest cables for every application they encounter. But you can’t just use the thickest wiring for every task. After all, thick conductors are more expensive than their thin counterparts. Additionally, they are less flexible and more challenging to manipulate.

You need the correct wire size for each application. Don’t ignore the number of conductors because this factor affects heat dissipation. The more insulated conductors you bundle together, the worse the heat dissipation.

How Do You Check Amps On A 10MM Cable?

Buy a clamp meter. You can measure the current running through a 10mm cable without cutting it open. If you don’t have a clamp meter, you can cut the line open and use an ammeter.

But this method is useless. It will show you the amount of electricity running through the cable, not the volume of current it can tolerate without overheating.

Fortunately, you don’t have to calculate a cable’s amperage. A table is more convenient. Many tables reveal the different cable sizes and their corresponding amperage.

But what if your tables show the wire size in ‘AWG’ instead of ‘MM?’ While the US prefers AWG, many international markets measure the wire size in ‘MM.’ The AWG standard has been around since the 1800s. Therefore, it is more widespread than you realize.

Electrical world has a formula for converting the wire size. But you can ignore it. The formula isn’t necessary because the website has published a table you can use to find a cable’s size. It shows the AWG and its corresponding diameter in MM. They want you to remember that a smaller number in AWG refers to thicker conductors.

An example is 8AWG, which is a smaller figure than 10AWG. But 8AWG can carry more electricity than 10AWG.

‘MM’ is the opposite. 10MM is thicker than 1.25MM. You should also realize that converting MM to AWG doesn’t produce exact numbers. But you can eliminate the decimal points by rounding up or down.

Nicab has also provided a table that shows wire sizes in AWG and MM2. From this table, you can see that 10MM is 8AWG. You can find the amperage of 8AWG in one of a million tables on the internet. This will give you the amp rating of 10MM wiring.

But you don’t have to convert MM to AWG. It is much easier to check the cable physically. Look at the insulation. More than likely, the wire size in AWG is printed on the jacket.

What Is 10MM Cable Used For?

10MM cables are typically used for grounding purposes. The conductors are compatible with heavy-duty household appliances.

Does Distance Matter For 10MM Cable?

The distance matters. Conductors have resistance. Electricity has to flow against that resistance when it moves through a conductor. This produces heat. The resistance increases with the distance. As a result, elevating the distance will also increase the heat generated. A long wire is more likely to overheat than a short wire.

More importantly, the voltage drop will become a problem. The voltage drop shouldn’t exceed 3 percent.

Considering 10mm cable equals 8awg with a voltage drop of 3% using single-phase line with respective voltage 120, 240 & 480 volts can carry maximum distance up to 62, 124, 248 feet

Voltage DropVoltagePhaseMaximum Distance
3%120Single Phase62 feet
3%240Single Phase124 feet
3%480Single Phase248 feet

Considering 10mm cable equals 8awg with a voltage drop of 3% using 3-phase line with respective voltage 120, 240 & 480 volts can carry maximum distance up to 71, 143, 287 feet

Voltage DropVoltagePhaseMaximum Distance
3%1203 Phase71 feet
3%2403 Phase143 feet
3%4803 Phase287 feet

The best way to control the voltage drop is to increase the size with the length. Get a thicker conductor if you need a longer cable that covers a greater distance. Because smaller gauges have more resistance, you can reduce the resistance and voltage drop despite the significant distance by getting a thicker cable.

10MM is quite thick, especially in a domestic setting. But it isn’t the thickest. Don’t be afraid to exceed 10MM if you want the conductors to cross large distances.

10MM Max VS Min Amps

10mm cable can tolerate a maximum current of 64 amps while the minimum current of 32 amps

You have to limit the current running through cables that don’t have proper ventilation. They cannot dissipate the heat they generate. But if the wires are clipped directly, they can carry as much as 65 or 70 amps.

How Many Watts Can 10MM Cable Take?

Cable SizeAmpsVoltWatt

To get the wattage, you have to multiply the voltage and amperage. For instance, you can calculate the wattage of a 10MM 40A cable in a 120V service if you multiply 120V by 40 amps. This gives you 4,800 watts.

You cannot determine the watts unless you know the voltage and amperage.

10MM Armored cable Amp Rating

10MM armored cables can accommodate 75 amps. Armored cable has a higher amp rating. It has a protective layer that allows the wires to survive in harsher settings whose conditions would typically corrode ordinary wires.

You can run 10MM armored cables underground without worrying that insects and rodents will ruin them. They are a perfect addition to construction sites, factories, and subways.

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