For a qualifying single-phase residential service that supplies the full electrical load of one dwelling, 2 AWG aluminum wire is a commonly referenced size for a 100 amp service under NEC dwelling-service provisions. This answer should not be applied automatically to every 100 amp feeder, subpanel, workshop, commercial building, or long cable run.
Electrical service work involves serious shock, fire, and equipment risks. The final wire size, conductor type, installation method, and terminal requirements should be confirmed by a licensed electrician and the local authority having jurisdiction.
The breaker rating is only one part of conductor selection. Two projects can both use a 100 amp breaker while requiring different wire sizes.
The commonly quoted 2 AWG size generally applies to a qualifying residential service or feeder carrying the entire load of an individual dwelling.
A 100 amp feeder supplying only a detached garage, workshop, apartment subpanel, commercial space, or part of a building may need to be sized under different ampacity rules.
Aluminum conductors may be installed as service-entrance cable, individual conductors in conduit, underground cable, or overhead service conductors.
The selected product must be approved for the actual installation environment. A conductor suitable for dry conduit may not be suitable for a wet underground raceway.
A conductor can meet the basic ampacity requirement and still create excessive voltage drop over a long distance.
Voltage drop can cause:
Weak appliance performance
Motor-starting problems
Dim or unstable lighting
Unnecessary heat
Reduced usable voltage at the panel
An electrician may increase the conductor size when the meter and panel are far apart.
High ambient temperatures can reduce conductor capacity. Several current-carrying conductors grouped inside one conduit may also require adjustment.
Terminal temperature ratings, conductor insulation, raceway fill, and surrounding conditions must all be checked before installation.
Aluminum wire should only be connected to terminals and lugs approved for aluminum conductors.
The installer must check:
AL or AL/CU terminal markings
Correct conductor stripping
Suitable lug size
Manufacturer-specified tightening torque
Oxide-inhibiting compound when required
Correct grounding and bonding
Protection from water and physical damage
Aluminum naturally develops a thin oxide layer. Poor preparation, loose terminals, or incompatible hardware can increase connection resistance and create dangerous heating.
The conductor should not be repeatedly bent near the terminal, and strands should not be cut away simply to make an oversized wire fit a smaller lug.
Copper has higher electrical conductivity by volume, so an aluminum conductor normally needs a larger cross-sectional size to carry a similar load.
This does not make aluminum unsuitable. Aluminum is widely used in service and transmission applications because it provides useful conductivity at a lower weight and often at a lower material cost.
The conductor must still be an electrical-grade product with the correct insulation, listing, and code approval.
A proper service calculation should confirm:
Service voltage
Single-phase or three-phase supply
Main breaker rating
Residential or commercial application
Whether the conductor carries the full dwelling load
Total cable distance
Overhead or underground installation
Conduit or cable type
Ambient temperature
Utility requirements
Panel terminal rating
Applicable code edition
The local electric utility may also have service requirements that go beyond the building code.
Electrical aluminum wire is manufactured and certified for carrying current. Extruded Aluminum Profiles are structural or functional components selected according to alloy, cross-section, wall thickness, strength, finish, and dimensional tolerance.
Our factory focuses on aluminum profiles for LED lighting, solar mounting, architectural structures, general applications, and industrial systems. Our production equipment includes extrusion machines, aging furnaces, and powder-coating lines for different profile sizes and finishes.
We do not treat structural aluminum profiles as replacements for certified electrical conductors. Buyers sourcing electrical cable should work with a qualified cable manufacturer and confirm all required approvals.
For many qualifying 100 amp residential services, 2 AWG aluminum is a common starting answer. The actual project may require a larger size because of feeder classification, distance, temperature, installation method, or local rules.
The conductor should be selected as part of the complete electrical design rather than from breaker size alone.
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