HOLT Electricians Practice Exam

When is sealing not required for conduits entering an explosion-proof enclosure?

1. All conduits must be sealed at all times

2. If the conduit is longer than 10 feet

3. If it remains unbroken and is within 12 inches of the unclassified location

4. If the conduit is made of non-metallic material

The correct answer is: If it remains unbroken and is within 12 inches of the unclassified location

Sealing is an important safety measure in electrical installations, especially for conduits entering explosion-proof enclosures. In the context of this question, the correct answer indicates that sealing is not required if the conduit remains unbroken and is within 12 inches of an unclassified location. This exemption is based on the understanding that the potential for hazardous materials or explosive atmospheres primarily exists beyond the unclassified area. If the conduit is intact and extends only a short distance into the unclassified location, there is a reduced risk of ignition or explosion since there is no break in the system that could allow gases or vapors to enter the explosion-proof area. The requirement for sealing conduits is more stringent as they penetrate into classified areas where the potential hazard exists. In essence, maintaining the integrity of the conduit up to that point minimizes the risk of triggering a hazardous situation. The other choices reflect scenarios where sealing would typically be mandatory due to safety concerns and regulatory standards governing electrical installations in potentially explosive environments.