What is Hazardous Locations

According to the NEC (NFPA 70), hazardous locations are "areas where fire or explosion hazards may exist due to flammable gases or vapors, flammable liquids, combustible dust, or ignitable fibers or flyings." In these areas, the presence of such materials can endanger electrical components and the individuals working with them. Therefore, strict precautions must be taken to ensure that electrical wiring, conduits, and fittings are properly installed and connected to mitigate risks.

Different Classes of Hazardous Locations

The NEC divides hazardous locations into three primary classes:

1. Class I (NEC Article 501): This class encompasses areas where inflammable gases or vapors are present in quantities sufficient to create explosion or flammable mixture risks. It is further divided into two divisions. Division 1 includes locations where a hazardous atmosphere is likely to occur during normal operations. Division 2, on the other hand, involves areas where volatile flammable liquids or gases are handled, processed, or used, typically within closed containers or systems.
2. Class II (NEC Article 502): Class II hazardous locations are characterized by the presence of combustible dust. Similar to Class I, this class has two divisions. Division 1 includes areas where combustible dust is suspended in the air under normal conditions in quantities that can form explosive or ignitable mixtures, or where equipment malfunctions can create an ignition source. Division 2 refers to areas where combustible dust is not normally suspended but can accumulate and interfere with the heat dissipation of electrical equipment.
3. Class III (NEC Article 503): Class III hazardous locations involve the presence of easily ignitable fibers or flyings in quantities that can produce ignitable mixtures. Division 1 covers areas where these fibers or materials are handled or manufactured, while Division 2 includes areas where they are stored or handled.

Can Flexible Conduit Systems Meet Safety Requirements?

Flexible liquid tight conduit systems can indeed meet safety requirements, but within specific limitations. These systems are suitable for installation in Class I Division 2 hazardous locations. However, current regulations for Class I Division 1 hazardous locations (NEC Article 501) only permit the installation of rigid conduits, liquid tight cables, or wiring. No flexible liquid tight conduits should be installed in Class I Division 1 areas due to the heightened risk of ignition.

The Advantages of Flexible Conduit Systems in Hazardous Locations

Flexible liquid tight conduit systems offer a practical and efficient solution for electrical installations in hazardous locations. They can significantly reduce installation and maintenance time and labor. The liquid tight jackets and fitting seals act as a reliable barrier, separating electrical components from volatile substances in the environment. This prevents sparks or hot wiring from igniting flammable materials, thereby enhancing overall safety.

In addition to their safety benefits, these conduits and fittings are designed to be corrosion, oil, and flame resistant. They are well - suited for harsh environments where regular maintenance may be challenging. The liquid tight seals effectively keep out corrosive atmospheres, sprays, and dirt, protecting critical electrical connections from damage and extending the lifespan of the electrical system

Available Options for Hazardous Locations

There are several types of approved conduit systems for different hazardous location applications:

• Halogen - Free Conduits: Ideal for installation in confined spaces, tunnels, and under raised floors, these conduits eliminate the risk of toxic halogen gas release in case of a fire.
• High - Temperature Conduits: Designed to withstand a wide range of operating temperatures, from below freezing to well above the boiling point of water, making them suitable for extreme environments.
• Ant - Static Conduits: These are a great choice for locations where airborne dust poses a hazard, as they help prevent static - related ignition risks.
• Food - Grade Conduits: Specifically designed for food and pharmaceutical production areas, they meet strict hygiene requirements and can withstand frequent washdowns and decontamination processes.
• Non - Metallic Conduits: Perfect for applications that require frequent bending and high resilience to impacts, they offer flexibility without compromising on protection.

When choosing a conduit system for hazardous locations, look for certifications such as those from Underwriters’ Laboratories (UL). These certifications ensure that the products meet stringent safety standards.

In conclusion, understanding the different types of hazardous locations and the appropriate conduit systems is essential for maintaining electrical safety. Flexible conduit systems, when used within the specified regulatory limits, can provide a reliable, efficient, and safe solution for electrical installations in challenging environments.

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