What is RHH/RHW-2? The Versatile "All-Rounder" of Building Wire

Understanding RHH/RHW-2 Wire 

When it comes to residential and industrial-grade wiring, the "alphabet soup" of cable types can be confusing. However, RHH/RHW-2 stands out as one of the most versatile building wire options available. Whether you are running power to a new sub-panel, wiring an industrial motor, or setting up a solar array, here is why this wire is a staple for professional contractors.

Decoding the Name

Let's break down the acronym to understand the performance of this wire.

• R: Originally stood for Rubber, but in modern cables, it signifies XLPE (Cross-Linked Polyethylene) insulation. This is a "thermoset" material, meaning it is chemically cured to never melt or drip under extreme heat—a massive safety advantage over standard PVC.

• H: Heat resistant.

• HH: High heat resistant (up to 90°C).

• W: Water resistant (suitable for wet locations).

• -2: Means the wire maintains a 90°C rating in wet/dry conditions. Standard RHW is limited to 75°C. 

What is the Difference Between RHH and RHW-2?

In the modern electrical world, you will almost always find these two paired together.

• RHH is technically the rating for dry locations (like inside a building's conduit).

• RHW-2 adds the ability to be used in "wet" locations (like an underground conduit that might fill with water). By carrying both ratings, the wire is versatile enough to handle almost any environment.

By carrying both ratings, the wire is versatile enough to handle various environments, from a hot attic to a damp underground trench.

The "Triple Rating" Advantage: USE-2 / RHH / RHW-2

At Wire America, our stock is frequently Triple-Rated (USE-2/RHH/RHW-2), meeting the standards of both UL 854 (Service Entrance) and UL 44 (Thermoset Insulated Wires).

1. USE-2 allows the wire to be buried directly in the ground.

2. RHH/RHW-2 allows that same wire to be pulled into a building.

The Benefit: You can run one continuous wire from an outdoor underground trench (as USE-2) directly into a service panel inside the building (as RHH/RHW-2) without needing a junction box to switch wire types. This eliminates a potential point of failure and saves significant labor, time, and money.

SHOP USE-2/RHH/RHW-2 WIRE>>

RHH/RHW-2 vs. THHN: What is the Difference?

While THHN is the most common wire for basic residential projects, RHH/RHW-2 offers a major technical upgrade for demanding environments.

The primary difference lies in the chemistry of the insulation. THHN uses a Thermoplastic (PVC) jacket with a thin nylon skin; if it gets too hot, the plastic can melt, drip, or become brittle. In contrast, RHH/RHW-2 uses XLPE (Cross-Linked Polyethylene), which is a Thermoset material. During manufacturing, the molecules are chemically "locked" together, meaning the insulation will not melt or drip even under severe electrical overloads or extreme heat.

Copper vs. Aluminum: Which do you need?

We offer RHH/RHW-2 in both aluminum and copper constructions allowing to choose whats best for your budget & environment. 

Key Technical Specs

• Insulation: Chemically Cross-Linked Polyethylene (XLPE)

• Voltage: 600V Rated

• Conductors: Available in both copper and aluminum stranded conductors.
  

• Standards: UL 854 (Service Entrance) & UL 44 (Thermoset Insulated)

• Temperature: 90°C Continuous in both Wet and Dry locations

• Compliance: NEC Article 310 and 338

What is RHH/RHW-2 Used for?

How Wire America can help

Not sure which gauge or material you need for your project? Our team specializes in utility, residential, commercial and industrial-grade wire & cable solutions. 

Call us today at (833) 268-8644 or email info@wireamerica.com for support. 

Browse our full selection of RHH/RHW-2 USE-2 Building Wire here>>

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At Wire America, we believe in genuine conversation. You'll always talk with real people who understand that every project requires careful product selection. We're here to ensure you feel educated, confident, and great about your final purchase. Feel free to give us a call to discuss your project! You can reach us at: 833-268-8644

⚠️ Important Disclaimer: Safety and Compliance

Wire America provides this information as a guide only. Electrical installations must strictly adhere to the National Electrical Code (NEC) and all state, local, and jurisdictional requirements, which vary widely. Always consult a licensed electrician, electrical engineer, or the local inspecting authority before purchasing material or starting any electrical project. Wire America assumes no liability for the installation, use, or interpretation of these guides.