IMPORTANT: If the power exhaust accessory is to be installed on the unit, the hood shipped with the unit will not be used and must be discarded. Save the aluminum filter for use in the power exhaust hood assembly.
3.The indoor coil access panel will be used as the top of the hood. Remove the screws along the sides and bot- tom of the indoor coil access panel. See Fig. 24.
4.Swing out indoor coil access panel and insert the hood sides under the panel (hood top). Use the screws provided to attach the hood sides to the hood top. Use screws provided to attach the hood sides to the unit. See Fig. 25.
5.Remove the shipping tape holding the economizer barometric relief damper in place.
6.Insert the hood divider between the hood sides. See Fig. 25 and 26. 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.
SIDE
PANEL
| TOP |
| SIDE |
| PANEL |
| CAULK |
| HERE |
INDOOR | INDOOR |
COIL | COIL |
ACCESS | ACCESS |
PANEL | PANEL |
Fig. 24 — Indoor Coil Access Panel Relocation
TOP
PANEL
INDOOR COIL
ACCESS PANEL
LEFT |
|
HOOD | SCREW |
SIDE | B |
| 19 1/16” |
33 3/8”
HOOD DIVIDER
Fig. 25 — Outdoor-Air Hood Construction
17 1/4”
DIVIDER
OUTSIDE 
AIR
HOOD
CLEANABLE
ALUMINUM 
FILTER
FILTER
BAROMETRIC RELIEF
FILTER CLIP
Fig. 26 — Filter Installation
7.Open the filter clips which are located underneath the hood top. Insert the aluminum filter into the bot- tom 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. 26.
8.Caulk the ends of the joint between the unit top panel and the hood top. See Fig. 24.
9.Replace the filter access panel.
10.Install all EconoMi$er IV accessories. EconoMi$er IV wiring is shown in Fig. 27.
Barometric flow capacity is shown in Fig. 28. Outdoor air leakage is shown in Fig. 29. Return air pressure drop is shown in Fig. 30.
F. EconoMi$er IV Standard Sensors
Outdoor Air Temperature (OAT) Sensor
The outdoor air temperature sensor (HH57AC074) is a 10 to 20 mA device used to measure the
Supply Air Temperature (SAT) Sensor
The supply air temperature sensor is a 3 K thermistor located at the inlet of the indoor fan. See Fig. 31. This sensor is factory installed. The operating range of temperature measurement is 0° to 158 F. See Table 3 for sensor tempera- ture/resistance values.
The temperature sensor looks like an eyelet terminal with wires running to it. The sensor is located in the “crimp end” and is sealed from moisture.
Outdoor Air Lockout Sensor
The EconoMi$er IV is equipped with an ambient tempera- ture lockout switch located in the outdoor airstream which is used to lockout the compressors below a 42 F ambient tem- perature. See Fig. 21.