Whether you’re rewiring a garage, adding a subpanel, or running power to an outbuilding, pulling wire through conduit is a key part of ensuring a safe and code-compliant electrical installation. While it might seem straightforward, the process requires planning, proper tools, and a clear understanding of code requirements. Here’s a breakdown of how it’s done—and what to avoid.
What Is Electrical Conduit?
Electrical conduit is a protective tube that houses and routes electrical wiring. It safeguards the wires from physical damage, moisture, sunlight, and other hazards. Common types of conduit include:
- PVC (Polyvinyl Chloride): Lightweight, corrosion-resistant, and great for underground or outdoor use.
- EMT (Electrical Metallic Tubing): Thin-walled steel or aluminum; widely used in commercial and residential applications.
- Rigid Metal Conduit (RMC): Thick, strong, and used where durability and protection are paramount.
- Flexible Conduit: Ideal for tight spaces and areas requiring mobility or adjustments.
When Is Conduit Required?
The National Electrical Code (NEC) may require conduit in the following scenarios:
- Underground electrical runs
- Exposed wiring in garages, basements, or utility rooms
- Areas where Romex (NM cable) is not allowed
- Commercial or outdoor applications
Using conduit not only protects your wiring but makes future upgrades and repairs easier and safer.
Steps to Pull Wire Through Conduit
1. Plan Your Route
Calculate your run length, identify the number of bends, and select the proper wire size. NEC limits the total bend angle between pull points to 360°—any more and you’ll need an accessible junction box.
2. Use Wire Lubricant as Needed
For longer or more complex pulls, a wire-pulling lubricant can help reduce friction and prevent insulation damage.
3. Use a Fish Tape or Pull String
- Short runs: Use fish tape to manually guide the path.
- Longer runs: Use a vacuum and foam piston to blow in mule tape, then attach wires for pulling.
4. Attach Wires Cleanly
Secure the wire ends in a staggered, tapered formation using electrical tape. Avoid bulky or sharp edges that could catch inside the conduit.
5. Pull Gently and Evenly
Teamwork is best—one person feeds while the other pulls. Communicate throughout the process. If you hit resistance, stop and assess—never force a pull.
Tips for a Clean and Code-Compliant Pull
- Use sweep bends instead of sharp 90s when possible.
- Always de-burr conduit ends before pulling wire.
- Stay within NEC conduit fill limits to prevent overheating.
- Label or color-code wires when pulling multiple conductors for easy identification.
Common Mistakes to Avoid
- Skipping conduit fill calculations: Overfilling conduit can lead to overheating, difficult pulls, and code violations.
- Pulling too quickly: This can damage wire insulation and lead to future faults.
- Running different voltage classes in the same conduit without proper planning:
This is often misunderstood. NEC 300.3(C)(1) allows conductors of different systems (such as 120V and 277V) to occupy the same raceway if all conductors are rated for the highest voltage present. As long as insulation types (e.g., THHN) and voltage ratings are the same and adequate (typically 600V), it’s allowed. Always verify that every wire meets or exceeds the highest system voltage.
When to Hire a Pro
Pulling wire through conduit may seem like a DIY-friendly job, but complex routes, high voltage systems, or large commercial runs should be handled by a licensed electrician. Hughes Electric LLC has years of experience installing conduit systems that are safe, efficient, and NEC-compliant.
Need Help with Your Electrical Project?
Hughes Electric LLC serves residential and commercial customers across New Hampshire with expert electrical installation, panel upgrades, and conduit wiring. Contact us today to schedule a consultation.
