What is the difference between a junction box and Pull Box?

When planning or installing electrical systems, it is crucial to understand the difference between junction boxes and pull boxes for safety, efficiency, and compliance with codes. Although both serve as enclosures in conduit systems, their functions and design intents differ.

 

1. Purpose and Function

✅ Junction Box:

A junction box is used to house wire splices or connections.

Electricians install them at points where:

Wires are joined, split, or branched.

Electrical loads are transferred between circuits.

Key roles:

Protect wire connections

Organize wiring

Prevent exposure to moisture, dust, or mechanical damage

✅ Pull Box:

A pull box is designed to aid in pulling long or heavy electrical cables through conduit runs.

They are installed when:

Conduit length exceeds code limits for a single pull.

Multiple 90° bends make cable pulling difficult.

Large-gauge wires are used.

Key roles:

Ease wire installation

Prevent cable damage from tension or friction.

Allow future access for maintenance.

Important: Pull boxes do not contain wire splices or electrical connections.

These electrical junction boxes are available in both metal and plastic options, offering reliable protection for electrical connections in a variety of settings. The plastic enclosures, made of ABS or PC material, are lightweight and corrosion-resistant, ideal for indoor use. The metal boxes provide added durability and shielding for outdoor or industrial environments. All models support customizable configurations and come with IP66 waterproof ratings for enhanced performance.

 2 Physical Differences

特徴	Junction Box	Pull Box
Size	Typically small to medium	Usually larger for cable access
Contents	Wire connections/splices	Only cables being pulled through
Access Panels	May be fully enclosed	Often has removable covers
Mounting Location	Walls, ceilings, device outlets	Inline with long conduit runs

3 Code Compliance (NEC-Based)

Junction boxes must be used where splicing is required and should remain accessible.

Pull boxes are required when:

Conduit runs exceed 100 ft (30 m)

There are more than two 90° bends in a run

Wire size or conduit fill makes pulling difficult

Always refer to NEC Article 314 and local building codes for installation guidelines.

 

4 Why It Matters: Expert Insight

Incorrectly using a pull box in place of a junction box—or vice versa—can lead to:

Code violations

Increased risk of fire or circuit failure

Difficulties during inspection or maintenance

Professional electricians and contractors always select the enclosure based on function, location, and safety requirements.

5 Summary Table

特徴	Junction Box	Pull Box
Wire Splicing	✅ Yes	❌ No
Used for Cable Pulling	❌ No	✅ Yes
Typical Size	Small to medium	Medium to large
NEC Function	Wire connection point	Access for wire pulling
Installation Use	Residential/commercial wiring	Long conduit runs, industrial setups

Conclusion

Use a junction box when you need to make or protect wire connections.

Use a pull box to ease the installation of long, heavy, or complex wire runs.

Each has a distinct role in ensuring safe, compliant, and efficient electrical systems.

Pull boxes and junction boxes are used for different purposes. Use a pull box when you need to pull wires through long or bent conduits. Use a junction box when you need to connect and protect wires. Choosing the right one helps keep your system safe and up to code.

Not sure which one to use? ホーフェンファブ tech support team is ready to help. We can guide you on box types, sizes, and materials to fit your project. Contact Hofengfab today for expert advice and custom solutions.