Electricity is an important part of our everyday lives nowadays. To supply this electricity to various places where we need it, wires are important. Different kinds of wires are required for different kinds of wiring.
You may ask what size of wire you need for a 70 amp breaker. Let us investigate and find out which wire is suitable for this kind of need along with some important facts about it as well.
What size wire do I need for a 70 amp breaker?
You will need 4 gauge copper wire for a 70 amp breaker. This is the general rule of choosing a wiring size for a certain type of wiring. This wire is an average of 22 mm2 in size and is a 4 AWG wire. You can also use 2 AWG aluminum wires as well if preferred. But the copper wire is a better choice.
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There are various kinds of wires available in the market. But not all of them will work for wiring a 70 amp breaker. A 70 amp breaker will require a heavy-duty wire to supply big loads of electricity. Thus, you will need to purchase 4 gauge copper wire.
4 gauge copper wire is certified for 70 amp electricity supply under any temperature. This wire can supply 70 – 85 amps within temperatures of around 140 – 167 degrees Fahrenheit. Therefore, 4 gauge copper wire is the perfect wire choice for a 70 amp breaker.
You may also think 4 AWG aluminum wire is another great option to use with a 70 amp breaker. But there are some problems with using an aluminum wire. It is said by experts that aluminum is not the best for transferring electricity.
For that, copper is the best choice among all other wires.
Moreover, you will have to use thick wires to get the necessary amps if you use aluminum wire. This may cause problems with the wiring in your building. Therefore, copper wire is the best choice for you.
There are various kinds of wires available in the market. Let us help you know about a certain wire that is perfect for a 70 amp breaker:
Gauge copper wire for 70 amp breaker:
Among all the wires of this class, 4 gauge copper wire is the best for this use. It can supply 70 – 85 amps at a certain temperature without any issue. Moreover, this wire is better for electricity transfer.
Can I use a 6 THHN gauge wire with 70 amp breaker?
Yes, you can use a 6 THHN gauge wire with a 70 amp breaker. 6 THHN gauge wire can provide around 55 – 70 amp of electricity to the breaker. Although it can provide the required electricity to the 70 amp breaker, it will depend on the temperature of your area.
If the temperature of your area is high around 170 Fahrenheit, this particular wire can provide you the necessary amount of electricity required for the breaker. But whenever the temperature drops below that, it cannot provide 70 amp electricity.
Thus, you will have to keep in mind the temperature while you wire a 70 amp breaker using this particular wire.
What size ground wire do I need for a 70 amp sub panel?
You will need 6 THHN gauge wires for a 70 amp sub panel. THHN wire is certified to be used underground without any doubt. If you maintain the basic rules of digging the hole at the proper depth and environmental facts, you can use this wire without any doubt.
Whenever you think about using a wire underground, this wire is better than any aluminum or copper wire. It can supply the necessary 70 amp of electricity to the sub-panel without any problem and provide protection from any kind of damage.
What determines which size wire to use for a breaker?
There are various ways that you can use to determine which size wire to use for a breaker. Here are some factors that we think you should maintain when choosing the correct wire for a breaker in a building:
The amp of the breaker:
When choosing a wire for your breaker, you have to check the amp of the breaker. Depending on the amp of the breaker, you have to choose the wire.
The amp of the breaker will be written on the breaker itself or it may be written on the box of the breaker that it comes with.
Distance of the breaker from the mainboard:
Distance between the breaker and mainboard is another factor in choosing a wire. You may need to use higher gauge wires if the distance between the breaker and mainboard is significant.
Moreover, the amount of power that is distributed from the mainboard is another fact as well.
Temperature of the area:
Temperature plays an important role in the selection of wires. Experts provide charts based on an optimal temperature. But the size will vary based on the temperature in your area where the building is situated.
How do I calculate what size wire I need?
Choosing the proper wire size is crucial. This ensures that all the areas that your wires will receive the necessary amount of electricity according to their need. There are various ways to calculate the size of wire you will need to properly wire the building that you want.
The simplest way to find the size that you will need is to find the amp rating of the breaker that you will connect. You will find that rating on the breaker itself or on the box that it comes with. Finding this amp rating is crucial for choosing the appropriate wire size.
After you find the amp rating of the breaker, you will have to choose the wire now. For 7 amps you will need 18 gauge wire. Therefore, for 10, 15, 20, 30, 40, 55, 70 & 95 amps you will need 16, 14, 12, 10, 8, 6, 4 and 2 gauge wire.
What is a 70 amp breaker used for?
A 70 amp breaker is basically used for electricity distribution in the electrical board. As it works with heavy loads in most cases, it is common to see that it will be used for heavy load operation.
Here are some use cases that we think are noteworthy to tell of where this 70 amp breaker is used:
Feed for a large load:
You may need to provide electricity load to heavy loads like a welder and air compressor. For providing power to such electrical components, a 70 amp breaker is perfect for an uninterrupted power supply.
Feeding smaller circuits in a subpanel:
Distributing power to smaller circuits in a subpanel is vital in building wiring. For that, a 70 amp breaker is perfect to feed those smaller breakers. It can provide the perfect amount of electricity to them.
Final thoughts
You will need a 4 gauge copper wire in order to use a 70 amp breaker. You can also use a 2 AWG aluminum wire as well for this kind of wiring. But the copper wire is always preferred by experts and electricians for maximum electrical transmission in the system.