Cables in conduit with a gas/vapour tight continuous sheath capable of transmitting gases or vapors through the cable core shall be sealed in Division 1 after removing the jacket and coverings.

Cables in conduit with a gas/vapour tight continuous sheath capable of transmitting gases or vapors through the cable core shall be sealed in Division 1 after removing the jacket and coverings.

• A. by sealing and splicing the cable
• B. after removing the jacket and coverings
• C. by applying compound to the cable
• D. by splicing within a seal

Answer: (B)

In Division 1 hazardous locations, preventing gas or vapor from migrating through a cable’s core is essential. Cables with a gas/vapor tight continuous sheath can still transmit vapors along the core, so the seal must be made after the jacket and coverings are removed. This allows the sealing medium to contact the exposed insulation directly and form a true barrier around the core inside the enclosure, rather than relying on the jacket to block any path. Other methods like sealing while the jacket remains, splicing the cable, or splicing within a seal wouldn’t reliably stop vapor migration through the core, so the required practice is to seal after removing the jacket and coverings.

In Division 1 hazardous locations, preventing gas or vapor from migrating through a cable’s core is essential. Cables with a gas/vapor tight continuous sheath can still transmit vapors along the core, so the seal must be made after the jacket and coverings are removed. This allows the sealing medium to contact the exposed insulation directly and form a true barrier around the core inside the enclosure, rather than relying on the jacket to block any path. Other methods like sealing while the jacket remains, splicing the cable, or splicing within a seal wouldn’t reliably stop vapor migration through the core, so the required practice is to seal after removing the jacket and coverings.