Intrinsically Safe Cables: ATEX & Class I Div 1 Guide

Intrinsic Safety (IS) is a low-energy signaling technique that prevents explosions from occurring by ensuring energy transferred to a hazardous area is well below the energy output required to initiate an explosion. The energy levels generated are significantly smaller but usable and more than adequate for many instrumentation systems. Specifically, the two forms of energy that can initiate an explosion are Sparks and hot surfaces. In other words, the electrical and thermal output is the cause of hazardous reactions. And, like any electrical equipment, the Intrinsically Safe cable exists to limit the risk of hazards at the worksite.

How do you make a cable intrinsically safe?

Electrical cables are already sealed and are sometimes regarded as IS when protected from damage, external electrical or magnetic fields (EMI), and isolated from non-IS circuits. Additionally, junctions and switches pose as potential hazardous ignition points in these environments and electrical circuits.

Intrinsically Safe cables contain a blue coating that identifies the potential risk of the electric circuit and the need for special consideration. Furthermore, strong sheathing materials such as polyurethane protect the cables to prevent any mechanical damage that could compromise electrical safety.

Contrarily, Non-IS cables contain a grey coating and carry currents in Non-IS circuits.

Types of Intrinsically Safe Cables

Each Intrinsically Safe cable is a type of control cable. Moreover, each cable is UV and weather-resistant according to ISO 4892-2. Cables are protection type ‘i’ for an IS circuit design; that also come in a range of sizes:

• OLFLEX EB for a flexible, intrinsic safety barrier circuit
• OLFLEX EB CY for high-degree screening of low transfer impedance
• OZ-BL (and other variations) for flexible control & measuring in hazardous areas

To learn more, ask our experts at 832 699 6726 Monday through Friday, 9am-5pm CST

Also read our article on What makes a flashlight Intrinsically Safe