ABB ACS800 Hardware Manual page 25

Cooling Air Flow
Provide the drive with the amount of clean cooling air given in "Technical Data" /
"NEMA Ratings".
Enclosure Ratings
NEMA 1 (NEMA Standard 7-15-1991)
Type 1 enclosures are intended for indoor use primarily to provided a degree of
protection against limited amounts of falling dirt.
UL Type 1 (ANSI/UL50)
Indoor use primarily to provide protection against contact with the enclosed
equipment and against a limited amount of falling dirt.
Recommendation
NEMA 1 / UL Type 1 enclosures should be applied to clean environments without
circulating dust or other contaminants that may collect on surfaces. Equipment of
this enclosure rating should be applied to clean electrical room or installed in another
enclosure with higher degree of protection. NEMA 1 / UL Type 1 enclosures typically
are not the best selection for installation on industrial factory floors.
NEMA 12 (NEMA Standard 7-15-1991)
Type 12 enclosures are intended for indoor use primarily to provide a degree of
protection against circulating dust, falling dirt, and dripping noncorrosive liquids.
UL Type 12 (ANSI/UL50)
Indoor use to provide a degree of protection against dust, dirt, fiber flyings, dripping
water, and external condensation of noncorrosive liquids.
Recommendation
NEMA 12 / UL Type 12 enclosures should be used in environments that contain
circulating dust or other contaminant particles. NEMA 12 / UL Type 12 enclosures
are recommended for most applications in industrial factory floor where dust is
present but spraying liquids are not.
Regular preventative maintenance of filter changing or cleaning is required. Inspect
the enclosure and installed equipment for dust or particle build up that may limit
cooling, clean as needed.
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Mechanical Installation