Which Size AWG Wire Should You Use For 100 Amp Service?
One of the most common questions wire and cable buyers ask is: Which wire gauge to use for 100 amp service, and which type of cable to choose? The truth is that you can use many types of copper and aluminum wire in a 100-amp service. Options include THHN, XHHW, UF-B, USE, and SER.
Typical sizes of wires for 100 Amp Service are 4 AWG or 2 AWG for copper wiring and 2 AWG, 1 AWG, or 1/0 AWG for aluminum or copper-clad wiring. These sizes are also used for direct burial.
When choosing 100 amp service wire size, remember that a 100 amp circuit at 240V can proceed up to 24,000W of electricity.
If the run of the wire is significantly long, such as over 100 feet, you should use a larger size out of the sizes described above to accommodate for voltage drop.
The ground wire size for 100 Amp service is different. You would typically use 8 AWG copper grounding wire or 6 AWG aluminum grounding wire.
Where is 100 AMP Service Used?
Is 100 amp service enough for your home? The answer depends on the size of your home and your appliances.
A 100-Amp service panel is typical for mid-size private houses and apartments with several 240-volt appliances and basic air conditioning. It is quite standard for older homes that have a limited number of appliances.
While 100-amp service is enough for such homes, it is not common for larger houses with the combination of electric and gas appliances and high-power demand. In these houses, 150 amp and 200 amp services are more common. 100 Amp service is not good for houses over 3,000 square feet with central air conditioning or electric heat.
Other basic applications of a 100 amp service panel are detached garages, workshops, agricultural facilities, and temporary power at the construction sites. 100 Amp service may also be used to feed different subpanels and circuit breaker panels in residential, commercial, and industrial buildings. In general, a 100 AMP service is very common, and you can find a 100 amps sub panel everywhere.
Types Of Wire Used in 100 Amp Service
Wires Used in 100 Amp service are different depending on whether it is copper or aluminum wire. Both are perfectly fine to use in these panels. For commercial applications, flame-retardant, plenum or riser-rated, and low-smoke zero halogen cables should be used.
Types of Copper Wire For 100-amp Service Panels
Common types of copper wire used in 100 Amp service are THHN/THWN-2, USE-2 RHH RHW-2, XHHW, type MC cable, copper SER cable, and UF-B cable. The last one is suitable for underground service.
- THHN/THWN-2 and XHHW-XHHW-2 are used in conduit.
- USE-2 RHH RHW-2 can be used for underground service entrance applications.
- Copper SER is a popular choice for panels and subpanels. Make sure to choose the cable with a suitable size of a ground wire.
- Type MC cable has a protective armor and can be used without conduit.
- UF-B cable is used for underground service and as a direct burial cable.
Types of Aluminum Wire For 100-amp Service Panels
Aluminum wire for 100 AMP service is just as good as copper wire as long as you choose the correct size.
Common types of aluminum wire used in 100 Amp service are:
- 2-2-2-4 Dyke Quadruplex Aluminum Conductor Underground Direct Burial 600V URD
- SER service entrance cable
- XHHW
- USE-2 (approved for underground service)
Most of these have the same characteristics as their aluminum counterparts, but one cable that is specifically aluminum is 2-2-2-4 Dyke Quadruplex Aluminum Conductor Underground Direct Burial 600V URD.
2-2-2-4 Dyke Quadruplex Aluminum Conductor Underground Direct Burial 600V URD is an all-around great budget-friendly choice for 100 amp service. This cable is suitable for wet and dry applications, as well as for underground service and direct burial.
If you still have questions about different types of electric wiring in service panels, here are a couple of posts to clear things up:
