Hood box – Bryant 549B User Manual

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5. Remove the shipping tape holding the economizer

barometric relief damper in place.

6. Insert the hood divider between the hood sides. See

Fig. 18 and 19. Secure hood divider with 2 screws on
each hood side. The hood divider is also used as the
bottom filter rack for the aluminum filter.

7. Open the filter clips which are located underneath

the hood top. Insert the aluminum filter into the
bottom filter rack (hood divider). Push the filter into
position past the open filter clips. Close the filter clips
to lock the filter into place. See Fig. 19.

8. Caulk the ends of the joint between the unit top panel

and the hood top. See Fig. 17.

9. Replace the filter access panel.

10. Install all EconoMi$er IV accessories. EconoMi$er IV

wiring is shown in Fig. 20.

Barometric flow capacity is shown in Fig. 21. Outdoor air
leakage is shown in Fig. 22. Return air pressure drop is
shown in Fig. 23.

D. EconoMi$er IV Standard Sensors

Outdoor Air Temperature (OAT) Sensor
The outdoor air temperature sensor (HH57AC074) is a 10 to
20 mA device used to measure the outdoor-air temperature.
The outdoor-air temperature is used to determine when the
EconoMi$er IV can be used for free cooling. The sensor is
factory-installed on the EconoMi$er IV in the outdoor air-
stream. See Fig. 14. The operating range of temperature
measurement is 40 to 100 F.

Supply Air Temperature (SAT) Sensor
The supply air temperature sensor is a 3 K thermistor
located at the inlet of the indoor fan. See Fig. 24. This sensor
is factory installed. The operating range of temperature
measurement is 0° to 158 F. See Table 5 for sensor
temperature/resistance values.

The temperature sensor looks like an eyelet terminal with
wires running to it. The sensor is located in the “crimp end”
and is sealed from moisture.

Outdoor Air Lockout Sensor
The Economi$er IV is equipped with an ambient tempera-
ture lockout switch located in the outdoor airstream which is
used to lock out the compressors below a 42 F ambient tem-
perature. See Fig. 14.

Hood

Box

HOOD BOX
BRACKET

Fig. 16 — Hood Box Removal

SIDE
PANEL

INDOOR
COIL
ACCESS
PANEL

CAULK
HERE

TOP
SIDE
PANEL

Fig. 17 — Indoor Coil Access Panel Relocation

TOP
PANEL

INDOOR COIL
ACCESS PANEL

24 9/16”

SCREW

HOOD DIVIDER

LEFT
HOOD
SIDE

40 3/8”

Fig. 18 — Outdoor-Air Hood Construction

22 1/4”

DIVIDER

BAROMETRIC
RELIEF

CLEANABLE
ALUMINUM
FILTER

FILTER

HOOD

FILTER
CLIP

OUTSIDE
AIR

Fig. 19 — Filter Installation