Installation manual

IM-487 Page 43
Preparing Unit for Operation
Relief Damper Tie-Down
(RDS 800-802 units only)
Economizer sections with a 30" or 40" return fan have a
relief damper that is tied down for shipping. Two brackets
and two screws must be removed before operation to allow
free movement of dampers. Access is from inside the econo-
mizer section.
Spring Isolated Fans
Release of Spring Mounts
Spring-mounted supply and return fans are locked down
for shipment.
Return Fans
Hold-down fasteners are located at each spring mount. These
fasteners must be removed before operating the fans.
The front mounts on RDS 800-802 return fans are accessible
by removing a 3" OD closure plug in the louvered fresh air
intake. Replace the plug after removing the lock-down bolts.
If it is necessary to change or replace the forward (front) iso-
lators on the RDS 800 or 802 return fan, proceed as follows:
1. Open fresh air intake louver door and remove the triangu-
lar shaped floor pan (remove sheet metal screws).
2. Forward spring mount is now visible and can be replaced.
3. Caulk all edges of the floor pan before reinstalling to pre-
vent leaks.
Supply Fans
Hold-down fasteners are located at each of the two spring
mounts on the inlet side of the fan base. A third hold down
fastener is located on the fan base directly below the bearing
on the wheel side of the fan assembly. Refer to Figure 49.
Figure 49. Supply Fan Assembly
Figure 50 shows a typical spring mount. Note that the 3/8"
hold-down bolt securing the fan base to the unit cross chan-
nel must be removed, as well as all 1/4"screws directly above
the spring mount.
In some unit arrangements, one of the 3/8" hold-down bolts
lies below the motor base. The bolt can be reached with a
9/16" socket and must be removed.
After removing the hold-down fasteners, rock by hand the
fan assembly to check for freedom of movement.
Figure 50. Spring Mounted Hold-Down Fasteners - All Units
WARNING
Moving machinery hazard.
Can cause severe injury or death.
Lock out and tag out all power and lock off before servic-
ing equipment. More than one disconnect may be
required to de-energize unit.
H o l d - d o w n
F a s t e n e r s
H o l d - d o w n
F a s t e n e r s
3
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( M a y b e s e c u r e d t o
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i t h e r f l a n g e o n
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r o s s c h a n n e l ) ;
R e m o v e B e f o r e
R u n n i n g F a n
1 / 4 " H o l d - d o w n S c r e w ;
R e m o v e B e f o r e
R u n n i n g F a n