Enclosures for overcurrent devices are permitted to be used as junction boxes provided the wiring is being added to an enclosure forming part of an existing installation and the conductors and splices do not fill up the wiring space at any cross-section to more than _________of the cross sectional area of the space.
A. 40% b. 53% c. 31% d. 75% Rule #
Rule 12-3034(2)(b). Paraphrased, the CEC Handbook Intent for this rule states "Where wiring is required to be added to an existing installation, the Rule permits the existing enclosures to be used as junction boxes or as raceways provided that the conductors, splices, and taps do not fill the cross-sectional area of the space to more than 75% and that conductors run through the enclosure do not fill the wiring space at any cross-section to more than 40% of the cross-sectional area of the space.
This is an exception for existing installations only and is not an acceptable practice for new installations where the design can incorporate the required enclosures for the wiring systems."
Electrical Safety Authority