Rockwell Automation 1512A MV Controllers, 400A One-High Cabinet, Standard and Arc-Resistant Enclosure - Manual (Page 76)

68 Rockwell Automation Publication 1512A-UM100F-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 plenum based, ArcShield line-up includes a plenum exhaust piece that
extends beyond either the left or right ends of the line-up. The other end of the
plenums 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 64 - Elements of ArcShield Plenum