Conduit Types & Their Applications

A Comprehensive Overview

In the world of electrical installations, conduit plays a crucial role in protecting and routing electrical wiring. Whether you’re a DIY enthusiast or a professional electrician, understanding the different types of conduits and their applications is essential to ensure safe and efficient wiring systems. 

This article provides a comprehensive overview of the various conduit types available and their specific applications in residential, commercial, and industrial settings.

What is a Conduit?

A conduit is a tube or trough that protects electrical wires from physical damage, moisture, chemicals, and other environmental factors. Conduits come in different materials and styles, each suited for specific applications depending on the location, load, and type of wiring required.

Types of Electrical Conduits

Several types of electrical conduits are available, each with its advantages, limitations, and best use cases. The most common types include:

Rigid Metal Conduit (RMC)

Material: Galvanized steel or aluminium

Applications:

• Heavy-duty protection in industrial and commercial installations
• Outdoor use, especially where wires are exposed to harsh environments like construction sites or factory settings
• Underground installations (direct burial)

Key Features:

• Extremely durable and provides excellent protection from physical damage
• Corrosion-resistant, especially in the galvanised steel variant
• Requires threaded fittings, making it more time-consuming to install

Intermediate Metal Conduit (IMC)

Material: Galvanized steel

Applications:

• Suitable for outdoor, indoor, and exposed applications
• Frequently used in industrial buildings or facilities with large wiring installations

Key Features:

• Lighter than RMC but provides similar levels of protection
• Easier to install than RMC
• Ideal for areas that need strong protection without the weight of rigid conduits

Electrical Metallic Tubing (EMT)

Material: Thin-walled steel or aluminium

Applications:

• Common in residential and commercial buildings
• Indoor wiring where physical damage is minimal

Key Features:

• Lightweight and easy to bend, making it ideal for flexible installations
• Requires compression or clamp-type fittings instead of threaded ones
• Provides moderate protection but is not suitable for extreme outdoor conditions

Flexible Metal Conduit (FMC)

Material: Spiral-wound metal strips

Applications:

• Frequently used in tight spaces, such as inside walls or around obstructions
• Ideal for retrofitting or making quick adjustments to wiring layouts

Key Features:

• Highly flexible, allowing easy installation around curves and angles
• Provides less physical protection than rigid conduits but more versatility
• Often used to connect fixed appliances like water heaters, furnaces, and pumps

Liquid-Tight Flexible Metal Conduit (LFMC)

Material: Coated flexible metal conduit

Applications:

• Outdoor installations exposed to moisture or water
• Ideal for areas where movement, vibration, or moisture is present, such as HVAC units and outdoor equipment

Key Features:

• Liquid-tight covering prevents water ingress, making it suitable for wet environments
• Offers flexibility while providing more protection than FMC
• Commonly used for applications requiring frequent movement or exposure to harsh weather

PVC Conduit (Polyvinyl Chloride)

Material: Rigid plastic

Applications:

• Outdoor and underground installations where corrosion resistance is essential
• Wet locations, including pools, spas, and outdoor lighting

Key Features:

• Lightweight, non-conductive, and corrosion-resistant
• Available in various grades and schedules for different levels of wall thickness and strength
• Can be glued together using PVC cement, simplifying installation

Rigid Non-Metallic Conduit (RNC)

Material: PVC or other non-metallic substances

Applications:

• Ideal for direct burial in concrete or underground use
• Suitable for environments with high moisture or corrosive chemicals

Key Features:

• Non-conductive and resistant to water and corrosion
• Lightweight and easy to install, though not as durable as metal conduits
• Often used in environments where electrical grounding isn't necessary

Electrical Non-Metallic Tubing (ENT)

Material: Corrugated plastic

Applications:

• Designed for indoor use in dry locations
• Popular in residential construction and for low-voltage wiring installations

Key Features:

• Extremely lightweight and flexible, simplifying the installation process
• Snap-lock fittings make assembly quick and easy
• Best used in areas with limited risk of mechanical damage

Choosing the Right Conduit

Choosing the correct conduit for your application involves considering several factors, including:

Location

Where the conduit will be installed plays a vital role in selecting the appropriate type. Outdoor and underground installations typically require a more durable and corrosion-resistant option like RMC, IMC, or PVC. Indoor installations in areas with minimal physical hazards can make use of lighter, more flexible options like EMT or FMC.

Moisture and Corrosion Resistance

In areas exposed to moisture or corrosive substances, non-metallic options like PVC and RNC are preferred, as they offer protection from these elements. LFMC is a great option if you require flexibility in addition to moisture resistance.

Flexibility vs. Durability

If flexibility is more important than durability (such as in areas with tight turns or small spaces), flexible conduits like FMC and LFMC are ideal. However, if the installation is in an area prone to damage, a more durable conduit like RMC or IMC should be selected.

Cost

The cost of conduits can vary significantly depending on the material. While metal conduits offer durability, they are often more expensive. For installations where cost is a concern, non-metallic conduits like PVC or ENT can be a more affordable alternative, especially in less critical applications.

Conduit Fittings

Conduit fittings are essential components that allow conduits to connect to junction boxes, electrical panels, or other sections of conduit. These fittings include elbows, couplings, connectors, and reducers, each serving a specific purpose depending on the type of conduit used.

• Compression Fittings: Used with EMT and ensure a tight seal.
• Threaded Fittings: Required for RMC and IMC.
• Snap-lock Fittings: These are common with flexible conduits like ENT and FMC for quick installation.

Best Practices for Conduit Installation

When installing electrical conduits, it's important to follow some best practices to ensure safety and reliability:

• Ensure Conduit Sizing: The conduit should be appropriately sized for the number and size of wires it will carry.
• Proper Grounding: Metal conduits should be properly grounded to prevent electrical hazards.
• Use of Appropriate Tools: When cutting or bending metal conduits, use the right tools to avoid damaging the conduit or wire insulation.
• Avoid Sharp Turns: Sharp bends can damage electrical wires. Conduit bends should follow specified radii to protect the electrical system's integrity.

Conclusion on Conduit Types & Applications

Understanding the different types of conduits and their applications is vital for creating safe, efficient, and long-lasting electrical systems. Whether you're working on a small residential project or a large-scale commercial installation, choosing the right conduit can make all the difference in protecting your wiring and ensuring compliance with electrical standards.

At Brite Lighting & Electrical, we offer a wide range of high-quality conduits and fittings to suit every electrical need. We have the products and expertise to help you find the best solution for your project. Visit our conduit selection to explore our offerings today.