Cancels: IIK 548-36-17
IIK 548-36-26
9/15/95
Installation and Start-Up Instructions
Part Numbers CRECOMZR001A02 and CRECOMZR002A02
PACKAGE USAGE AND CONTENTS
UNIT
PACKAGE
NO.
CONTENTS
3 to 6
Tons
CRECOMZR
001A02
1 — Barometric Relief Damper Hood
2 — Hood Sides
1 — Hood Top
1 — Outdoor-Air Inlet Screen
1 — Screen Retainer Cap
2 — Spacers
1 — Horizontal Block-Off Plate
30 —
5
⁄
8
-in. no. 10 Screws
2 —
3
⁄
4
-in. no. 10 Screws
1 — Economizer with Control Board
Attached
1 — Outdoor-Air Thermostat (OAT)
1 — Knob
1 — Supply-Air Thermostat (SAT)
2 — Wirenuts
1 — Wire Tie
3 — Seal Strips
1 — Outdoor-Air Opening Panel
7
1
⁄
2
to
12
1
⁄
2
Tons
CRECOMZR
002A02
1 — Barometric Relief Damper Hood
2 — Hood Sides
1 — Hood Top
2 — Outdoor-Air Inlet Screens
1 — Screen Retainer Cap
3 — Spacers
1 — Horizontal Block-Off Plate
1 — Vertical Discharge Block-Off
Plate
40 —
5
⁄
8
-in. no. 10 Screws
3 —
3
⁄
4
-in. no. 10 Screws
1 — Economizer with Control Board
Attached
1 — Outdoor-Air Thermostat (OAT)
1 — Knob
1 — Supply-Air Thermostat (SAT)
2 — Wirenuts
1 — Wire Tie
1 — Screen Clasp
1 — Bottom Stop
3 — Seal Strips
1 — Outdoor-Air Opening Panel
GENERAL
Accessory economizer package utilizes cool outdoor air
to satisfy cooling load and minimize energy consumption.
Economizer cooling can be used alone or in conjunction with
mechanical cooling.
A standard economizer uses a dry bulb thermostat to sense
outdoor-air temperature. For a more efficient system, an ac-
cessory solid-state enthalpy control can be substituted for
the dry bulb thermostat.
Also available as an economizer accessory is the differ-
ential enthalpy control. This system compares the tempera-
ture and humidity of outdoor air and return air and then ad-
justs the economizer position to ensure the lowest enthalpy
air is used for cooling.
IMPORTANT: Read these instructions completely
before attempting to install the accessory economizer.
INSTALLATION
Turn off unit power! Electrical shock and personal in-
jury could result.
1. Determine quantity of ventilation air required. Record
amount of air for use in Step 10.
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 indoor coil access panel. Dis-
card panel and save screws. See Fig. 1.
3. Assemble outdoor-air hood top and side plates as shown
in Fig. 2. 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. On all 10 and 12
1
⁄
2
ton units, install vertical discharge
block-off plate over duct openings. See Fig. 3.
5. Slide economizer into unit and secure with screws. See
Fig. 4.
6. If barometric pressure relief is required, remove the hold-
down screw from the barometric relief damper and mount
the barometric relief damper hood around the damper
with the 4 screws supplied. The longest part of the hood
should be above the top of the damper.
7. To install the economizer for a horizontal discharge
application:
a. Install the economizer so that the motor faces the
outdoor-air section and secure with screws. See
Fig. 5.
b. If barometric pressure relief is required, rotate baro-
metric relief damper 90 degrees so that it opens and
closes vertically. Mount the barometric damper hood
around the damper with the supplied screws. The long-
est part of the hood should be above the top of the
damper.
c. Install horizontal discharge block-off plate over open-
ing on the access panel. Block-off plate MUST be
installed before installing hood assembly. See Fig. 6.
NOTE: Install spacers at the same time as the hori-
zontal block-off plate using same screws. The spac-
ers are used to cover gaps between the economizer
assembly and the unit.
Small Rooftop Units
Gas Heating/Electric Cooling, Electric Cooling, and
Heat Pump Units
3 to 12
1
⁄
2
Tons (50/60 Hz)
Accessory Economizer Package
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1
1
1
4
4
4
Tab
1a 1b 5a 5a 6a 6b
PC 111
Catalog No. 534-892
Printed in U.S.A.
Form 48/50-39SI
Pg 1
9-95
Replaces: 48/50-31SI
