Air-cooled heat exchanger (ACHE) drives can spin backwards when fans
are off but subjected to air movement across the fan blades. This is known as
back-drafting or wind-milling and can be dangerous. Technicians are often in
close contact with the drive, and in extreme situations bodily damage occurs
due to back-drafting. DraftguardTM anti-rotation device secures the drive from
spinning backwards during maintenance operations. Draftguard also protects the
entire system from extreme shock load which causes unnecessary wear of the
motor components and which can lead to belt breakage. Often design engineers don't consider the effect a drive which rotates
the opposite direction causes. Draftguard protects the drive from damage, or
other unsatisfactory events from occurring, when units back draft.† The design of the flange plate allows
Draftguard to mount on nearly any bushing or shaft which eliminates the need of
retrofitting drive components. Gates Draftguard can be mounted to prevent
rotation in either the clockwise or counter clockwise direction. It can easily
be mounted on either vertical or horizontal shafts and typically fits within
the existing fan cage.
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