What Is Romex?
Romex is a common trade name for nonmetallic-sheathed cable used in residential electrical wiring. The cable contains insulated conductors and a grounding conductor inside a protective outer jacket. Electricians use Romex to connect circuits between electrical boxes, outlets, switches, lights, and panels where the installation conditions allow this cable type.
Quick Facts About Romex
Category
Nonmetallic-sheathed electrical cable
Used for
Residential branch-circuit wiring
Common confusion
Romex is a trade name, not a universal cable type
Also called
NM cable, Nonmetallic cable
Often discussed with
Electrical Rewiring
Key Takeaways About Romex
- Romex has multiple conductors inside one protective jacket.
- Romex simplifies concealed wiring between electrical boxes.
- Romex is not the same as wire inside metal conduit.
How Romex Works
Romex works as a grouped cable assembly for electrical circuits. The outer jacket protects the insulated current-carrying conductors and the grounding conductor as the cable passes between approved wiring points. Each conductor connects to a specific part of the circuit, such as a hot connection, neutral connection, or grounding path.
Related glossary terms: Wire gauge, Junction box, Conduit.
Electricians route the cable through accessible building spaces and secure it near electrical boxes. The cable ends inside a box, where the conductors connect to devices or other circuit wiring. Cable markings identify the product and its permitted use, while the wire size and circuit protection must match the planned electrical load. Damaged, overheated, or improperly routed cable needs careful inspection during electrical rewiring.
From the Center Electric Service team
When we work on electrical rewiring, we inspect Romex for jacket damage, loose connections, and unsuitable routing. Our team also checks the cable markings, conductor condition, grounding path, and connection points before deciding whether existing wiring can remain in service.
Romex in Practice: A Real-World Example
During a home electrical rewiring project, Romex may run from the electrical panel through wall spaces to a bedroom outlet and light switch. The electrician routes the cable carefully and connects each conductor inside the approved electrical boxes.
Related Services
Related Terms
Wire gauge
Wire gauge is a sizing system that describes the diameter and current-carrying capacity of an electrical…
Junction box
A Junction box is an enclosed electrical container that protects wire connections and splices. Conductors enter…
Conduit
A conduit is a protective pathway for electrical wires and cables. It may be made from…
Neutral wire
A neutral wire is a current-carrying conductor that completes the electrical path from a load back…
Center Electric Service
Have Questions About Romex?
Contact Center Electric Service for practical guidance on Romex and related 24 hour electrician work in Riverside.