When installing a sub-panel, it is important to choose the right size wire for the job. The wire size will depend on a number of factors, including the distance between the main panel and the sub-panel, the amperage of the sub-panel, and the type of wire you are using. In this case, you are looking to install a 100 amp sub-panel 100 feet away, so let’s take a closer look at what wire size you will need.
The first thing you need to consider is the amperage of the sub-panel. A 100 amp sub-panel requires a wire size of at least #3 AWG copper or #1/0 AWG aluminum. The larger the amperage, the larger the wire size required. It is important to note that the wire size must be able to handle the full amperage of the sub-panel without overheating or causing a fire hazard.
Next, you need to consider the distance between the main panel and the sub-panel. The longer the distance, the larger the wire size needed. This is because the wire will experience voltage drop over distance. Voltage drop is the reduction in voltage that occurs when electricity is transmitted over a long distance. The longer the distance, the greater the voltage drop. This can cause problems such as dimming lights or equipment failure. To prevent voltage drop, you will need to use a larger wire size.
To determine the correct wire size for your application, you will need to calculate the voltage drop over the distance. This calculation requires several factors, including the amperage of the sub-panel, the length of the wire, and the resistance of the wire. There are online calculators and tables that can help you with this calculation, but it is important to make sure you are using the correct data for your specific situation.
For a 100 amp sub-panel located 100 feet away, you will need a wire size of at least #3 AWG copper or #1/0 AWG aluminum. This will ensure that the wire is able to handle the full amperage of the sub-panel without overheating or causing a fire hazard. However, you may need to use a larger wire size depending on the voltage drop calculation.
When choosing the type of wire to use, there are several options to consider. Copper wire is the most commonly used because it has a lower resistance than aluminum wire, which means less voltage drop. However, copper wire is also more expensive than aluminum wire. Aluminum wire is a good choice for longer distances because it is lighter and less expensive than copper wire. However, aluminum wire has a higher resistance than copper wire, which means more voltage drop.
In addition to the wire size, you will also need to choose the correct type of wire for your application. There are several types of wire available, including THHN, THWN, and XHHW. THHN wire is the most commonly used for indoor applications, while THWN and XHHW wire are suitable for both indoor and outdoor applications. It is important to make sure you are using the correct type of wire for your specific application to ensure safety and compliance with local electrical codes.
In summary, when installing a 100 amp sub-panel 100 feet away, you will need a wire size of at least #3 AWG copper or #1/0 AWG aluminum. However, depending on the voltage drop calculation, you may need to use a larger wire size. It is important to choose the correct type of wire for your specific application and to ensure compliance with local electrical codes. If you are unsure about any aspect of your sub-panel installation, it is recommended that you consult with a licensed electrician.