Install Economizer Hoods (48ZT,ZW Units) —
The economizer uses a total of 4 outdoor intake hoods, 2 on each side of the unit. See Fig. 37. Two small hoods (one per side) are
INSTALL SMALL HOODS — To install the small econo- mizer hoods, perform the following procedure:
1.Remove the 10 screws holding each of the small econo- mizer hood shipping covers in place.
2.Pivot hoods outward. (There are a total of 2 hoods.)
3.Apply seal strip to vertical flange of hood sides.
4.Install 15 screws (4 each side, 7 across top) around the outside of each hood. Screws are in the fastener package taped to the basepan inside the fan section.
5.Apply a bead of RTV or similar sealant to corner of econ- omizer hood at pivot point to prevent water leaks. (See Fig. 30.)
INSTALL LARGE HOODS — Large hoods are shipped dis- assembled in the economizer section of the unit behind the large economizer hood shipping cover. See Fig. 38 for assem- bly details for large economizer hoods. To install the large economizer hoods, perform the following procedure:
1.Remove the 17 screws holding each of the large econo- mizer hood shipping covers in place.
2.Remove the packages containing the disassembled large economizer hoods (total of 2 packages). Each package
contains the following: left hood side, right hood side, hood top, hood front, top filter flange, side filter flanges (4), bottom support, front support, filters (6), filter clips (9), seal strip, fasteners.
3.Place seal strip on backside of bottom support along en- tire length of support, covering 6 clearance holes.
4.Attach bottom support piece to unit. Be sure seal strip is between bottom support and panel on unit.
5.Place seal strip on
6.Attach the side filter flanges to the left and right hood sides, 2 on each hood side.
7.Attach left and right hood sides to unit. Be sure seal strip is between hood side and unit.
8.Place seal strip on
9.Attach top filter flange to hood top.
10.Attach top hood to unit and to hood sides. Be sure seal strip is between hood top and unit.
11.Attach front support between left and right hood sides.
12.Place seal strip on all filter flanges.
13.Attach filter clips to front and bottom supports.
14.Install filters and filter clips. Filters are held in place with filter clips.
15.Attach hood front to hood top and sides.
16.Apply RTV or similar sealant to 6 places shown in Fig. 38.
EXHAUST
AIR
LEGEND
PE VFD
ACCESS DOOR
AUXILIARY
CONTROL BOX
LARGE ECONOMIZER
HOOD LOCATION
POWER EXHAUST
ACCESS DOOR
SMALL ECONOMIZER
HOOD LOCATION
PE VFD — Power Exhaust Variable Frequency Drive
Fig. 37 — Economizer Hood Location — 48ZT,ZW Units
35