Optional Varislide™ Economizer - Carrier 48TJE Series Installation, Start-Up And Service Instructions Manual

OPTIONAL VARISLIDE ™ ECONOMIZER — The op-
tional economizer hood assembly is packaged and shipped
in the filter section. Damper blades and control boards are
installed at the factory and the economizer is shipped in the
vertical discharge position.
NOTE: Horizontal discharge block-off plate is shipped with
the air hood package. If unit is to be used for vertical dis-
charge application, discard this plate.
Assembly:
1. Determine if ventilation air is required in building. If
so, determine minimum amount to be supplied by each
unit and record quantity of ventilation air needed for use
in Step 7.
2. Remove filter access panel by raising panel and swing-
ing panel outward. Panel is now disengaged from track
and can be removed. No tools are required to remove
filter access panel. Remove outdoor-air opening panel.
Save panels and screws. See Fig. 17. Remove optional
outdoor-air damper hood package from filter section.
FILTER
ACCESS
PANEL
Fig. 17 — Typical Access Panel Locations
3. Assemble outdoor-air hood top and side plates as shown
in Fig. 18. Install seal strips on hood top and sides. Put
aside screen retainer and screws for later assembly. Do
not attach hood to unit at this time.
4. To convert to horizontal discharge application:
a. Rotate economizer 90 degrees until the economizer
motor faces the condenser section (see Fig. 19).
b. Rotate the barometric relief damper cover 90
degrees.
c. Install horizontal discharge block-off plate over the
opening on the access panel. (Block-off plate MUST
be installed before installing hood assembly.) See
Fig. 20.
5. Insert economizer plug into economizer harness. Re-
move tape from barometric relief damper. See Fig. 21.
6. If ventilation air is not required, proceed to Step 8. If
ventilation air is required, determine minimum position
setting for required airflow. See Fig. 22. Adjust mini-
mum position setting by adjusting the screws on the po-
sition setting bracket. Slide bracket until the top screw
is in the position determined by Fig. 22. Tighten screws.
7. Remove tape from outdoor-air thermostat (OAT). Fas-
ten OAT to inside of hood using screws and speed clips
provided. See Fig. 23. Make sure OAT terminals are
positioned up.
CONTROL BOX
PANEL
14
8. Replace outdoor-air opening panel using screws from
Step 2. Replace filter access panel. Ensure the filter
access panel slides along the tracks and is securely
engaged.
9. Fasten hood top and side plate assembly (Fig. 18) to
outdoor-air opening panel with screws provided.
10. Place knob supplied with economizer on OAT. See
Fig. 23. Set for 3° F below indoor room thermostat set-
ting. If accessory enthalpy control (EC) is used in place
of OAT, see instructions shipped with EC for installa-
tion and adjustment. See Fig. 23.
11. Connect OAT per Fig. 24.
12. Slide outdoor-air inlet screen into screen track on hood
side plate. While holding screen in place, fasten screen
retainer to hood using screws provided.
NOTE: Refer to Fig. 25 for economizer barometric relief damper
characteristics.
Fig. 18 — Outdoor-Air Hood Details
ECONOMIZER
CONTROL
BOARD
BAROMETRIC
RELIEF
DAMPER
ECONOMIZER
PLUG
ECONOMIZER
MOTOR
Fig. 19 — Horizontal Varislide™ Economizer
Installation