Filling Inertia Fan Base; Thrust Restraint Replacement And Adjustment; Rear Discharge Orientation; Figure 96 - Supply Fan Restraint - Pace PAI Installation And Assembly Manual

PACE │ Installation & Assembly Manual

FILLING INERTIA FAN BASE

Inertia fan bases are pre-engineered according to the
fan and motor size. Use the following instructions to fill
an inertia fan base with concrete.
• Calculate the amount of concrete by measuring
the overall length and width of the fan base as-
sembly cavities that have the corrugated metal
bottoms. The standard depth of a cavity is 4 in.
• Fill each cavity to the top with wet concrete. Do not
get concrete mix on the bolts and adjusting parts
of the adjustable motor base, sheaves, belts, or
on the floor under the edges of the isolated fan
base.
THRUST RESTRAINT REPLACEMENT
AND ADJUSTMENT
Fan segments are cabinets containing a fan and mo-
tor. They can develop extremely high thrusts. These
forces are horizontally opposite to the airflow. Thrust
restraints are provided for all fans when the air thrust
exceeds 15% of the equipment weight when the fan
discharge is rear (see Figure 96 on page 60). Any
other fan orientation does not require restraints due to
one of several reasons:

Figure 96 - Supply Fan Restraint

Issue Date: 07/03/2018
SECTION 3 - HANDLING, STORAGE, AND INSTALLATION
• Top and Top Inverted - Isolators function as thrust
restraints.
• Bottom and Bottom Inverted - The weight of the
fan/motor exceed potential thrust.
• Rear Inverted - The horizontal thrust component
is low with respect to the center of gravity of the
fan/motor assembly.

Rear Discharge Orientation

On forward curved fans, the thrust is un-
der 15% of the total weight. In this case,
the thrust restraints are not required.
On airfoil fans, it is required that thrust
restraints be used where the TSP is
greater than 6".
On plenum fans, it is required that thrust
restraints be used where the TSP is
greater than 3".
Tools Required
Two 8" crescent wrenches.
Material Required
Appropriate Thrust Restraint Kit.
Procedure
See Figure 96 on page 60 and Figure 97 on page
61.
60
LD08592-1
Form PA102.20-N1