In intrinsically safe apparatus, conduits and cables that are required to be sealed shall ___.

In intrinsically safe apparatus, conduits and cables that are required to be sealed shall ___.

• A. be explosionproof
• B. not be required to be sealed
• C. be flameproof
• D. minimize passage of gases, vapors, or dusts

Answer: (D)

Intrinsic safety protects by keeping electrical energy and fault energy so low that a spark or heat cannot ignite a surrounding atmosphere. When conduits and cables must be sealed in such systems, the goal is to minimize the entry or escape of hazardous gases, vapors, or dusts. This helps ensure that any internal fault cannot easily interact with flammable substances outside the enclosure. Explosionproof or flameproof ratings are different protection methods that deal with containing an ignition, not with limiting energy transfer in intrinsically safe circuitry. Sealing to minimize passage of contaminants is the appropriate, protective practice here.

Intrinsic safety protects by keeping electrical energy and fault energy so low that a spark or heat cannot ignite a surrounding atmosphere. When conduits and cables must be sealed in such systems, the goal is to minimize the entry or escape of hazardous gases, vapors, or dusts. This helps ensure that any internal fault cannot easily interact with flammable substances outside the enclosure. Explosionproof or flameproof ratings are different protection methods that deal with containing an ignition, not with limiting energy transfer in intrinsically safe circuitry. Sealing to minimize passage of contaminants is the appropriate, protective practice here.