Rockwell Automation 1512A MV Controllers - 800A One-High Cabinet - Manual (Page 75)

Appendix
A
1512A-UM102B-EN-P – June 2013
ArcShield Unit Information
Overview
ArcShield units have a robust arc resistant enclosure design that has been
tested per IEEE C37.20.7 (2001). Each ArcShield structure was tested to
withstand the effects of an arc flash at 40 kA for 0.5 seconds. ArcShield
units provide Type 2 Accessibility.
ArcShield Design
ArcShield units typically include a pressure relief vent on the roof of the
structure (some incoming units may not have a pressure relief vent if top
cable entry is required). Under arc flash conditions, the pressure relief
vent will open allowing hazardous flames and gases to exit the enclosure
via the plenum. The low voltage panel area is sealed to prevent flames and
gases from entering; however, suitable personal protective equipment
(PPE) must be used whenever working on live circuits.
A T T E N T I O N A T T E N T I O N
To ensure Arc resistant integrity, it is important to
ensure that the following rules are followed:
 The pressure relief vent may not be tampered with, and it is not to
be used as a step.
 No alterations can be made to the ArcShield structure.
 All covers and plates removed for installation or maintenance
purposes must be re-installed and properly secured. Failure to do
so voids the arc resistant integrity.
 Power cable entry points are to be treated as the boundary between
a hazardous location and sealed accordingly. Failure to do so voids
the arc resistant integrity.
 A plenum or chimney must be used to direct the arc flash energy to
a suitable location. Failure to do so voids the arc resistant integrity.
Refer to Appendix B for plenum installation instructions. Refer to
Appendix C for chimney installation instructions.
 All wiring between the low voltage panel and the power cell must
be routed through a suitable gland to ensure flames and gases are
not transmitted into this area (as fitted from factory).
 The medium voltage power cell doors must be properly secured,
using both the handle mechanism and the door bolts (refer to
instruction label on the power cell door and in Chapter 2). Failure
to do so voids the arc resistant integrity.