Plug-In Busway Under Raised Access Floor - Plenum

[publicgood]

300.22(C) is pretty clear. Plug-in busway under raised access floor are not permitted in a plenum application. My question comes with the wording of 368.10(B)(2). It makes it seem opposite of what 300.22(C) is saying. Also, are there concerns for working clearance of the plug-in units?

(B) Behind Access Panels. Busways shall be permitted to be installed behind access panels, provided the busways are totally enclosed, of nonventilating-type construction, and installed so that the joints between sections and at fittings are accessible for maintenance purposes. Where installed behind access panels, means of access shall be provided, and either of the following conditions shall be met:
(1) The space behind the access panels shall not be used for air-handling purposes.
(2) Where the space behind the access panels is used for environmental air, other than ducts and plenums, there shall be no provisions for plug-in connections, and the conductors shall be insulated.

 

[ron]

300.22(C) is pretty clear. Plug-in busway under raised access floor are not permitted in a plenum application. My question comes with the wording of 368.10(B)(2). It makes it seem opposite of what 300.22(C) is saying. Also, are there concerns for working clearance of the plug-in units?

(B) Behind Access Panels. Busways shall be permitted to be installed behind access panels, provided the busways are totally enclosed, of nonventilating-type construction, and installed so that the joints between sections and at fittings are accessible for maintenance purposes. Where installed behind access panels, means of access shall be provided, and either of the following conditions shall be met:
(1) The space behind the access panels shall not be used for air-handling purposes.
(2) Where the space behind the access panels is used for environmental air, other than ducts and plenums, there shall be no provisions for plug-in connections, and the conductors shall be insulated.

The first sentence of 300.22(C)(1) seems to agree with 368.10(B)(2). feeder busway is ok, but plug-in type is not.

 

[publicgood]

(2) Where the space behind the access panels is used for environmental air, other than ducts and plenums, there shall be no provisions for plug-in connections, and the conductors shall be insulated.

The piece "other than ducts and plenums" is the confusing part. If is not a duct or plenum, it is a space not for environmental air. #2 makes it sound like you can have plug-in units if it IS a duct or plenum. Am I reading this wrong or is the code just mis-written?

 

[GoldDigger]

1 and 2 are an either/or pair.
Either you do not use the space behind access panels containing a bus duct for air handling at all (not plenum, not duct, not other environmental air space) or if it is used only for other environmental air there cannot be plugins.

Not the ideal logical construction for clarity, but not ambiguous either.

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