A - arcshield unit information, Overview, Arcshield design – Rockwell Automation 1512B MV Controllers, 200/400A Two-High Cabinet, Standard and Arc-Resistant Enclosure User Manual
Page 79: Appendix a, Be found in, Arcshield unit information, Appendix
Rockwell Automation Publication 1500-UM055G-EN-P - May 2013
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Appendix
A
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 2B
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,
appropriate personal protective equipment (PPE) must be used whenever
working on live circuits. (Refer to NFPA-70E) or (SA-Z462 in North America).
ATTENTION: 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 resistance
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
for plenum installation instructions. Refer to
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 refer to
Opening the Medium Voltage Doors on page 22 of
). Failure to do so voids the arc resistance integrity.