The best way to determine the suitability of 8mm cables is to identify the number of amps they can safely carry.
How Many Amps Can 8mm Cable Carry?
8mm cables are the equivalent of 1/0 AWG. Thus it can carry up to 170 amps. However, it changes according to temperature settings & materials.
For copper cable,
- 8mm cable can carry 125 amps at 60˚C
- 8mm cable can carry 150 amps at 75˚C
- 8mm cable can carry 170 amps at 90˚C
For Aluminum Cable
- 8mm cable can carry 100 amps at 60˚C
- 8mm cable can carry 120 amps at 75˚C
- 8mm cable can carry 135 amps at 90˚C
8mm Cable Amps Rating
| Copper | Aluminum | |||||
| Wire Gauge Size | 60˚C NM-B, UF-B | 75˚C THW, THWN, SE, USE, XHHW | 90˚C THWN-2, THHN, XHHW-2, USE-2 | 60˚C TW, UF | 75˚C THW, THWN, SE, USE, XHHW | 90˚C XHHW-2, THHN, THWN-2 |
| 8mm | 125 | 150 | 170 | 100 | 120 | 135 |
As you may have guessed, the amps will change in response to the material. Copper is more conductive than aluminum. As such, it has a higher amp rating than aluminum.
Some people will encourage you to account for factors like the temperature setting. However, you are better off leaving considerations like the temperature in the hands of a professional, especially if you’ve decided to hire a licensed contractor.
A contractor can look at the setting to determine whether or not your application requires a higher temperature rating. The temperature rating is not simply associated with the ambient temperature.
Cables with a higher temperature rating can carry more electricity. For that reason, they cost more money.
What Is 8MM Wire Used For?
8mm wires are very thick. Thus, it will accommodate 12V and 24V batteries, speakers, and welding applications.
Most homeowners are familiar with 2.5mm cables because they appear in sockets. Additionally, you have probably encountered 1mm and 1.5mm because lighting circuits use this wire size.
Sizes of 6mm and above appear in appliances that use significant volumes of electricity. You require thicker conductors to accommodate cookers, showers, electric cars, and other heavy-duty devices.
Otherwise, you may start a fire by forcing a cable to transmit more current than it can handle.
People love 1/0 wires because they are universal. In other words, you can apply the same wire to different applications. If you have 1/0AWG copper conductors but want to use aluminum, increase the size.
Some people don’t expect aluminum conductors to replace copper wires because copper has superior conductivity. However, I don’t see anything wrong with using aluminum instead of copper if you can find an aluminum wire with the same temperature rating but a higher ampacity.
For instance, you can’t use 1/0 aluminum in place of 1/0 copper. You are better off using 2/0 aluminum to replace 1/0 copper. Otherwise, an application that can run on 1/0 copper may overload 1/0 aluminum.
You should leave decisions of this nature in the hands of a contractor. Let them select the appropriate aluminum replacement. Some people don’t see the point in using aluminum instead of copper when copper is more conductive.
But aluminum has plenty of benefits. For instance, it is much lighter. Anyone that has ever attempted to pull thick cabling through a conduit understands the impact lightweight wiring can have on the installation process.
How Many Watts Can 8mm Cable Handle?
| Amp | Voltage | Watt |
| 150A | 12V | 1800W |
| 150A | 120V | 18000W |
| 150A | 240V | 36000W |
| 150A | 480V | 72000W |
To determine the wattage, you have to remember that 8mm cables can transmit 150A. You find the wattage using this formula: P = I X V. I is the current in amps , P the power in watts, and V the volts.
If you live in the US, you probably use a conventional 120V system. In that case, 8mm wire has a wattage of 18,000W. But what if your house uses 240V? In that regard, you multiply 240V by 150A to get 36,000W.
As you can see, these figures are only correct if your wire has an amp rating of 150A. But as you know, the amps will vary depending on the temperature rating and material.
If the amps change, the wattage will also change. Keep this in mind. Don’t assume that your wires will carry 36,000 watts when the amp rating is 120A instead of 150A.
Fortunately, the formula for calculating the wattage is very easy. You can substitute the voltage and ampacity with the right figures to get the correct wattage.
8mm Cable VS Volt
If you want to determine the amp rating, the voltage doesn’t matter. The ampacity is determined by the wire size.
| Voltage | Amps |
| 12 V | 150A |
| 24 V | 150A |
| 120 V | 150A |
| 240 V | 150A |
Don’t forget: the wire size shows you the number of amps the conductors can carry without overheating. The voltage doesn’t factor into that equation. The voltage won’t change an 8mm cable’s amp rating.
On the other hand, if you want to select the appropriate insulation, the voltage is one of the most important considerations.
8mm Cable VS Distance
The distance cannot change a cable’s amp rating. This comes as a surprise to some laypeople because the tables they visit on the internet associate larger distances with higher ampacities.
Those tables are not wrong. However, some homeowners misinterpret them. A longer distance cannot change a cable’s amp rating. Instead, it will compel you to replace a line with a lower gauge with one that has a higher gauge.
This is because longer conductors have higher resistance, and a higher resistance can lead to overheating.
Consider an 8mm cable as an example. The wire’s ampacity is 150A regardless of whether it has to traverse 50 or 150 feet. However, 8mm cabling is more like to overheat at 150 feet because of the higher resistance. It will also plague your applications and appliances with significant voltage drops that may even interrupt their operations.
Therefore, your best bet is to get a thicker wire than 8mm. The cable’s ampacity has not changed. Instead, you have replaced the 8mm conductor with a thicker option that can cross 150 feet without overheating.
8mm Armored Cable Amp Rating
8mm Armoured cable can transmit as much as 210 amps. Armored cables appeal to consumers that want to install conductors in settings with harsh elements that typically expedite wear and tear. For instance, you can bury armored cables underground because they can withstand variables like pressure and pests.
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