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100 amp rated wire is designed to safely carry 100 amps of electrical current. It is commonly used for high power applications in residential, commercial and industrial settings. This article provides an in-depth look at 100 amp rated wire – how it works, the different types available, proper installation, safety considerations and typical uses.

100 Amp Rated Wire

Understanding Ampacity Ratings

The ampacity rating of a wire refers to the maximum current it can continuously carry without overheating. It is based on the wire’s material composition and thickness. For copper wire, a thicker gauge (lower AWG number) allows more current flow. Ampacity charts provide the rated amps for each gauge.

100 amp wire must have the appropriate thickness to handle that level of power. Overloading thinner wire past its ampacity rating can cause overheating, insulation breakdown and fires. Under-rated wiring cannot provide the power needed by connected loads. Using the right wire size for the expected load is critical for safety and performance.

Wire Gauges for 100 Amps

For residential and light commercial use, 100 amp circuits generally require 6 AWG or 4 AWG copper wire. Here are some common options:

  • 6 AWG copper – Rated for 65A (can handle 100A for limited distances)
  • 4 AWG copper – Rated for 85A
  • 2 AWG copper – Rated for 115A

6 AWG is the minimum size that should be used. 4 AWG provides a better safety margin and less voltage drop over longer cable runs. 2 AWG further increases capacity if required. These gauges are for general building wire with THHN or THWN-2 insulation at 75°C.

Conductor Materials

Copper is the standard material used for 100 amp electrical wire due to its high conductivity and durability. However, aluminum and copper-clad aluminum (CCA) wires are also available as cheaper alternatives and allowed by code for 100A circuits.

Some key points about each material:

  • Copper – Most conductive, durable and widely used. Provides easiest termination.
  • Aluminum – Lightweight, cheaper, and still reasonably conductive. Requires special terminations rated for aluminum wire. More prone to oxidation and thermal expansion issues.
  • CCA – Copper coating over aluminum core. Combines conductivity of copper with cost savings of aluminum. Requires proper terminations to account for dissimilar metals.

Insulation Types

Insulation is critical to prevent current from escaping the copper conductors and to protect from contact with other wires or grounded surfaces. Many types of wire insulation can be used for 100 amp circuits, including:

  • PVC (or vinyl) – Basic general-use insulation, rated to 75°C typically.
  • THHN/THWN-2 – Durable insulation rated for both wet/dry use up to 90°C. Common for 100A wire.
  • XHHW-2 – Similar to THHN but also resistant to sunlight/UV rays.
  • USE-2 / RHH / RHW-2 – Various rubber insulations, rated up to 90°C in wet or dry conditions.
  • Teflon / PTFE – Highly heat resistant up to 250°C. Used for high temp wire.
  • Cross-Linked Polyethylene (XLPE) – Durable, moisture resistant and heat resistant. Used for underground feeders.
  • The insulation material will be specified for the expected environment and maximum temperature of the wire run.

Uses of 100 Amp Wire

100 amp wire has many uses in residential and commercial settings:

  • Service entrance wires – Feeder lines from the utility to the electrical panel.
  • Main panel supply – 100A breaker with thick 6 AWG or 4 AWG wire is common for main power.
  • Subpanels – To supply additional circuit capacity to remote panels.
  • High power circuits – For central AC, electric stoves/ovens, machinery or other large loads.
  • Welder circuits – Welders can draw 70-100+ amps so thick wire is required.
  • Underground conduit runs – THHN or XHHW wire housed in PVC conduit below grade.
  • EV charging circuits – Electric vehicle chargers require up to 100A capacity wire.
  • PV solar arrays – To carry DC current from rooftop panels to inverter.

100 amp circuits can provide power distribution and control for many residential, commercial and industrial applications.

Installation Tips

When installing 100 amp rated wires, follow these guidelines:

  • Use approved insulation types like THHN/THWN-2 based on environment.
  • Maintain proper wire gauge – minimum 6 AWG for copper.
  • Use appropriate terminations and lugs rated for 100A. Tighten to specified torque.
  • Leave adequate space in boxes, conduit and panels for wire bending radius.
  • Clamp cables securely and provide protection from damage.
  • Use cable trays, conduit, or other wiring methods as specified by code.
  • Keep conductors isolated from each other and grounded surfaces.
  • Use copper for all terminations or use devices approved for other metals.
  • Label wire runs appropriately for voltage and load controlled.
  • Check overcurrent protection device (breaker/fuse) ratings match wire ampacity.
  • Size conduit properly based on number and thickness of conductors.
  • Inspect wiring thoroughly before energizing circuit.

Proper installation is critical to ensure 100 amp circuits operate safely and efficiently.

Safety Considerations

Exercise caution when working with 100 amp circuits:

  • Use PPE – Insulated tools, enclosed panels, eye/face protection.
  • De-energize and confirm wires are dead before starting work.
  • Check for proper grounding. Ground fault circuit interrupters (GFCIs) should also be installed.
  • Don’t overload small gauge wires past their ampacity rating.
  • Be mindful of voltage – many 100A+ circuits carry 240-480V.
  • Beware of aluminum wire hazards like oxidation or incorrect terminations.
  • Replace old, damaged or undersized wiring.
  • Keep flammable materials away from electrical sources.
  • Ensure all covers and barriers in place to avoid contact with live parts.
  • Service high amp circuits with qualified electricians.
  • Follow all electrical codes and permit requirements.
  • Post warning signs for high voltage installations.
  • Monitor cables during operation for hot spots or insulation damage.
  • Use cable management practices to avoid pinched wires or strain on connections.

Understanding proper safety procedures is critical when using large gauge, high ampacity wire. Following codes and best practices reduces risk of personal injury or property damage.

Published On: 2023年11月8日Categories: ,