An industrial electrician is asked to install a new control panel with several conduits entering from the bottom. The panel is located in a Class I, Division 2 hazardous location where flammable gases or vapours may be present in abnormal operating conditions. What specific CEC requirement must be met for the conduit entries to prevent the spread of gas into the panel or adjacent non-hazardous areas?

Question: An industrial electrician is asked to install a new control panel with several conduits entering from the bottom. The panel is located in a Class I, Division 2 hazardous location where flammable gases or vapours may be present in abnormal operating conditions. What specific CEC requirement must be met for the conduit entries to prevent the spread of gas into the panel or adjacent non-hazardous areas?

Answer options:

• All conduits must be sealed with a firestopping compound. ✅ A sealing fitting must be installed in each conduit entrance to the enclosure or within 450 mm (18 inches) of the enclosure.
• The conduits must be drained and vented to the atmosphere.
• Only liquidtight flexible metal conduit can be used for connections to the panel.

Correct answer: A sealing fitting must be installed in each conduit entrance to the enclosure or within 450 mm (18 inches) of the enclosure.

Explanation: CEC Rule 18-102(3)(b) specifically requires that in Class I, Division 2 locations, a sealing fitting must be installed in each conduit run entering an enclosure that contains arcing or high-temperature devices, or within 450 mm (18 inches) of such an enclosure, to prevent the passage of flammable gases or vapours.