Rockwell Automation 1512B MV Controllers, 200/400A Two-High Cabinet, Standard and Arc-Resistant Enclosure - Manual (Page 80)

72 Rockwell Automation Publication 1500-UM055G-EN-P - May 2013
Appendix A ArcShield Unit Information
Exhaust Systems: Chimney or
Plenum Option Plenum Information
A plenum can be provided for each unit, and is to be field-mounted on the top of
the unit structure (some incoming units may not have a plenum if top cable entry
is required). The purpose of the plenum is to direct the hazardous flames and
gases away from the top of the arc resistant enclosure. Unit plenums are secured
to the top of the unit structure and to adjacent plenums, creating a continuous
conduit for release of the arc flash energy. Refer to
Appendix B for plenum
installation instructions.
Each ArcShield line-up includes a plenum exhaust section that extends beyond
either the left or right ends of the line-up. The other end of the plenum is capped
with an end cover. Extensions can be added to the plenum to allow the arc flash
energy to be directed further away from the ArcShield line-up to an area where
safe venting of the plasma gases can occur.
Figure 69 - Elements of ArcShield Plenum