Can you use a box extension to add thru feed lugs to a NQ or NF panel?

No, this is not recommended.Box extensions do not contain box studs so there is nothing to attach themounting rails that come with the sub/feed thru lug kits. In the case of the 400A and largerinteriors, the longer box also means a longer vented trim. This wouldmove the vents on the trim down an additional 6 inches which allows the thru feed lugs to clear the trim vents. Adding a box extension does not move the trim vents away from the lugs and that results in the lugs being too close to the vents and arcing can occur.

Released for: Schneider Electric Canada