43
Large Chassis
To install the Vertical Economizer on the large chassis perform the
following procedure:
1. Turn off unit power supply and install lockout tag.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing or servicing system, always turn off main
power to system and install lockout tag. There may be more
than one disconnect switch. Turn off accessory heater
power switch if applicable.
!
WARNING
2. Remove economizer hood top panel from the return side of
the unit. See Fig. 34. Keep screws and panel next to the
unit.
3. Remove red shipping tape that attaches the outside air
temperature (OAT) sensor to the economizer assembly and
place sensor next to the unit.
4. Remove horizontal return duct cover panel and cut the wire
ties that hold the hood divider to the economizer assembly.
Slide hood divider off from the two slots holding it in place
and place next to the unit. See Fig. 35.
NOTE
: Gas units have a flue hood attached to the hood divider.
Unscrew the fastener holding the flue hood in place and dispose
the screw. Follow unit’s literature for flue hood installations.
5. Replace horizontal return duct cover panel. Screw in place
ensuring all seams are air and watertight.
6. Open economizer hood package found on the top skid.
Mount OAT sensor to its assigned bracket by screwing
together with provided two #8 fasteners. Afterwards install
OAT sensor to the right side hood panel with the provided
#10 screws. See Fig. 36.
7. Install the 2 angle filter brackets to the right and left hood
side panels respectively with the #10 screws provided. See
Fig. 37.
8. Assemble hood according to Fig. 38 screwing together with
provided #10 sheet metal screws.
9. Install assembled hood over the economizer opening in the
replacement return chamber panel. See Fig. 39. Screw in
place through pre-punched holes. Make sure all seams are
watertight.
NOTE
: The two wires that connect to the outside air temperature
sensor (OAT) should remain accessible.
10. Connect the outside air temperature sensor (OAT) to the
economizer per wiring diagram.
OAT Sensor
Filter Access
Panel
Hoop Top
Panel
A09696
Fig. 34 -- Economizer Hood Top Panel Removal
Horizontal
Return Duct
Cover Panel
Hood
Divider
Hood Divider
(Removed)
A09697
Fig. 35 -- Horizontal Return Duct Cover Panel and Hood Divider Removal
674D
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A
Summary of Contents for Legacy 674D
Page 3: ...3 A09473 Fig 2 674D A24 36 Unit Dimensions 674D A...
Page 4: ...4 A09474 Fig 3 674D A42 60 Unit Dimensions 674D A...
Page 24: ...24 A10207C Fig 14 208 230 1 60 Connection Wiring Diagram Unit 674D 674D A...
Page 25: ...25 A10207L Fig 14 Cont 208 230 1 60 Ladder Wiring Diagram Unit 674D A 674D A...
Page 26: ...26 A10208C Fig 15 208 230 3 60 Connection Wiring Diagram Unit 674D A 674D A...
Page 27: ...27 A10208L Fig 15 Cont 208 230 3 60 Ladder Wiring Diagram Unit 674D A 674D A...
Page 28: ...28 A08019 Fig 16 Cooling Charging Table Subcooling 674D A...
Page 49: ...49 A10059 Fig 49 Economizer Wiring Diagram 674D A...
