What Size Wire Do You Need For A 200 Amp Service?

This post covers the basics of electrical wiring and includes a diagram to help you select the right size wire for your 200 amp service.

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If you’re planning to install a new 200 amp electrical service in your home, you’ll need to make sure that you have the proper size wire. The following guide will help you determine the right size wire for your 200 amp service:

-For a single-family home, you’ll need #4 copper or #2 aluminum wire.
-For a duplex or two-family home, you’ll need #3 copper or #1 aluminum wire.
-For a three-family home, you’ll need #2 copper or #1/0 aluminum wire.
-For a four-family home, you’ll need #1/0 copper or 2/0 aluminum wire.

The Basics of Electrical Wiring and Amperage

Electrical wiring is an important part of any home or office. It’s essential to know the basics of electrical wiring and amperage before beginning any wiring project. The size of the wire you’ll need will depend on the amperage of the circuit you’re wiring. A 200 amp circuit will require a larger wire than a 100 amp circuit.

What is Electrical Wiring?

In order to provide power to a home, business, or other structure, electrical wiring must be run to the site. This wiring can either be run underground or overhead, but it must be able to connect to the main power grid. Electrical wiring is made up of insulated cables that are used to carry electricity from the power source to the various outlets and appliances in the building. The size of the wire used will depend on the amount of electricity that needs to be carried, as well as the distance it needs to travel.

What is Amperage?

Amperage is the measurement of electric current flow. It is measured in amperes or “amps” (A). Amperage is a very important factor when working with electricity because it helps to determine the appropriate size of breakers, fuses and wire that should be used for a circuit.

The ampacity rating of a conductor is the measure of the amount of current that can flow through that conductor without exceeding its temperature rating. This measurement is important when determining the correct size wire for an electrical circuit. The wrong size wire can cause fires or damage to equipment.

Wire size is measured by its gauges. The lower the number, the thicker the wire and the higher the ampacity rating. The most common sizes used in electrical wiring are:
14 gauge – 15 A
12 gauge – 20 A
10 gauge – 30 A
8 gauge – 40 A
6 gauge – 60 A
4 gauge – 80 A

How to Choose the Right Size Wire for a 200 Amp Service

The size of the wire you need for a 200 amp service will depend on the length of the run and the gauge of the wire. The most common wire gauges used for a 200 amp service are 4/0 and 2/0. The 4/0 wire is the thicker of the two and is typically used for long runs, while the 2/0 wire is thinner and typically used for shorter runs.

Step One: Determine the Length of the Wire Run

The first step is to determine the length of the wire run from the main breaker panel to the subpanel. This will give you the base amount of wire you need to get the job done. Keep in mind that you will need extra wire for any accepted electrical code requirements, such as adding an extra foot or two of wire in case you need to make a repair down the line.

If your main breaker panel is located 100 feet from your subpanel, you will need at least 100 feet of 4/0 AWG aluminum wire (or equivalent) to complete the job.

Step Two: Determine the Number of Conductors

The next step is to determine the number of conductors, or “hot” wires, that you need for your 200-amp service. The main rule of thumb is that you’ll need two hot wires plus one neutral wire for each circuit. So, for a service with 30 circuits (common in a home), you’ll need 61 wires total: two hot wires plus one neutral wire for each of the 30 circuits.

Step Three: Select the Wire Gauge

based on the standards set by the National Electrical Code (NEC), while copper Romex 12-2 AWG wires are sufficient for 20-amp breakers, they are only allowed to be used on 60-amp breakers if they are rated for photovoltaic power systems. Under the NEC, THHN or THWN-2 copper wires must be used for wiring circuits rated at 60 amps or more.


As a rule of thumb, you’ll need two-stranded copper wire of 8 AWG (American Wire Gauge) for your 200 amp service. This will be sufficient to carry the current your home needs while also being able to handle any future electrical needs you may have.