Wire Sizing for a 200-Amp Electrical Service
A 200-amp electrical service is the standard for modern American homes and requires specific wire sizes to safely carry the full rated current from the utility meter to the main breaker panel. Using undersized wire on a 200-amp service creates a fire hazard, will fail inspection, and violates the National Electrical Code. Here are the exact wire specifications.
Copper Conductor Sizing
For copper conductors, 200-amp service requires 2/0 AWG (also written as “00” or “double-ought”) for the hot conductors. The neutral conductor is typically 1/0 AWG copper (one size smaller per NEC allowance for residential services). The ground conductor is 4 AWG copper. A complete copper service entrance cable is designated as 2/0-2/0-2/0-1/0 SER (three 2/0 conductors plus one 1/0 neutral) for a 3-wire plus neutral configuration. Copper provides the best conductivity per size but costs 2 to 3 times more than aluminum for equivalent ampacity.
Aluminum Conductor Sizing
For aluminum conductors (the most common choice for residential service entrance), 200-amp service requires 4/0 AWG for the hot conductors. The neutral conductor is typically 2/0 AWG aluminum. The ground conductor is 4 AWG copper (ground conductors are always copper regardless of the service conductor material). A complete aluminum service entrance cable is designated as 4/0-4/0-4/0-2/0 SER. Aluminum is the standard material for residential service entrance wiring because it provides the required ampacity at a fraction of the copper cost. IB Lighting stocks SER cable in both copper and aluminum configurations at our electrical wire collection.
Cable Types for 200-Amp Service
SER (Service Entrance Rated) cable is the standard for the meter-to-panel run. It contains the hot conductors, neutral, and is rated for service entrance duty. For underground service entrance (where the utility feed comes from below ground rather than overhead), USE-2 (Underground Service Entrance) rated conductors in conduit are required. THHN/THWN-2 conductors in conduit can also be used for service entrance runs, particularly for longer distances or when the installation requires conduit anyway.
Distance Considerations
The wire sizes listed above are for standard residential distances (typically under 100 feet from meter to panel). For longer runs, voltage drop becomes a factor. On a 200-amp circuit, every additional 50 feet of distance increases voltage drop. For runs exceeding 100 feet, upsizing to the next larger conductor (3/0 AWG aluminum or 1/0 AWG copper) is recommended to keep voltage drop under 3%. Your electrician will calculate the exact size needed based on the actual distance in your installation.
When You Need This Wire
The most common situations requiring 200-amp service entrance wire are new home construction, upgrading from 100-amp or 150-amp to 200-amp service to support a standby generator, EV charger, or additional electrical load, and replacing damaged or deteriorated service entrance cable. If you are installing a standby generator and your home currently has 100-amp service, your electrician may recommend upgrading to 200-amp service to accommodate both the generator transfer switch and your existing loads.
IB Lighting stocks SER cable and all service entrance wire types from Southwire. Browse our electrical wire and cable collection or call (800) 674-9019 for help with your specific project requirements.